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Johnson Johnson SERVICEMANUAL 1971-1989 1-60hp TABLE OF CONTENTS 1 SAFETY HEAD SERVICE 3-5 REED SERVICE 3-7 INTRODUCTION 1-1 Description CLEANING, WAXING, POLISHING 1-1 CONTROLLING CORROSION 1-2 Reed Valve Adjustment 3-8 Cleaning and Service PROPELLERS 1-2 Installation 3-10 FUEL SYSTEM 1-7 LOADING 1-9 BYPASS COVERS 3-10 HORSEPOWER 1-10 Installation 3-11 EXHAUST COVER 3-1 1 FLOTATION 1-10 EMERGENCY EQUIPMENT 1-12 COMPASS 1-15 ANCHORS 1-17 Cleaning 3-12 Installation 3-12 MISCELLANEOUS EQUIPMENT 1-18 TOP SEAL 3-13 BOATING ACCIDENT REPORTS 1-19 Removal 3-13 NAVIGATION 1-19 Installation 3-13 BOTTOM SEAL 3-14 Inspec tion 3-14 CENTERING PINS 3-15 2 TUNING INTRODUCTION 2-1 TUNE-UP SEQUENCE 2-2 COMPRESSION CHECK 2-3 SPARK PLUG INSPECTION 2-4 IGNITION SYSTEM 2-5 SYNCHRONIZING 2-5 BATTERY SERVICE 2-6 CARBURETOR ADJUSTMENTS 2-8 MAIN BEARING BOLTS AND CRANKCASE SIDE BOLTS 3-15 Installation 3-16 CRANKCASE COVER 3-16 Removal 3-16 Cleaning and Inspection 3-16 CONNECTING RODS AND PISTONS 3-17 Removal 3-18 FUEL PUMPS Disassembling 3-18 STARTER AND SOLENOID 2-10 Rod Inspection and Service 3-21 INTERNAL WIRING HARNESS 2-11 Piston and Ring Inspection WATER PUMP CHECK 2-11 and Service 3-23 PROPELLERS 2-12 Assembling 3-25 LOWER UNIT 2-13 CRANKSHAFT 3-27 BOAT TESTING 2-14 Removal 3-27 Cleaning and Inspec tion 3-29 CYLINDER BLOCK SERVICE 3-30 3 POWERHEAD Honing Procedures 3-30 Assembling 3-32 INTRODUCTION 3-1 Piston and Rod Installation 3-32 Theory of Operation 3-1 Crankshaft Installation CHAPTER ORGANIZATION 3-4 Needle Main and POWERHEAD DISASSEMBLING Rod Bearings 3 POWERHEAD (CONTI TYPE IV CARBURETOR Removal Crankshaft Installation Dis a sse mb ling 4-41 With Top Needle Main Brg. Cleaning and Inspecting 4-42 and Babbitt Ctr. & Bottom Assembling 4-46 With Top & Bottom Needle Installation 4-49 Brg. and Ctr. Babbitt Brg. With All Babbitt Main Brgs. 3-38 FUEL PUMP SERVICE 4-51 Crankshaft Installation Removal and lnstalla tion 4-51 Babbitt Main and Cleaning and Inspecting 4-51 Rod Bearings 3-39 Crankcase Cover Installation 3-40 FUEL TANK SERVICE 4-53 Main Bearing Bolt and Crankcase Side Bolt Instl. 3-41 ELECTRIC PRIMER CHOKE 4-55 Bottom Seal Installation 3-42 Reed Box Installation 3-43 MANUAL PRIMER CHOKE Head Installation 3-44 BREAK-IN PROCEDURES 3-44 OIL INJECTION SYSTEMS VRO Oil Inject. 4-57 AccuMix (AutoBlend) 4-62 4 FUEL INTRODUCTION GENERAL CARBURETION INFORMATION 4-1 5 IGNITION FUEL SYSTEM TROUBLESHOOTING INTRODUCTION 5- 1 Fuel Pump Tests Fuel Line Test 4-6 SPARK PLUG EVALUATION Rough Engine Idle 4-8 POLARITY CHECK Excessive Fuel Consumption WIRING HARNESS 5-4 Engine Surge 4-9 FLYWHEEL MAGNETO IGNITION JOHNSON/EVINRUDE 1.25 hp --1987 & on CARBURETORS 2 hp --1971-86 TYPE I CARBURETOR 4-11 2.5 hp --1987 & on Removal 4-11 4 hp --1971-84 Disassembling 4-12 6 hp --1971-76 Cleaning and Inspecting 4-13 9.5 hp --1971-73 Assembling 4-15 18 hp --1971-73 Installation 4-18 20 hp --1971-72 25 hp --1971-72 CHOKE SYSTEM SERVICE 4-19 40 hp --1971-73 ALL ELECTRIC CHOKE REMOVAL 4-20 TYPE II CARBURETOR 4-21 TROUBLESHOOTING Disassembling 4-21 Wiring Harness Cleaning and Inspecting 4-23 Key Switch 5-8 Assembling 4-25 Compression 5-10 Adjustments 4-30 Condenser 5-11 Breaker Points 5-12 TYPE III CARBURETOR 4-31 Removal 4-31 SERVICING FLYWHEEL MAGNETO Disassembling 4-32 IGNITION SYSTEM 5-13 Cleaning and Inspecting 4-33 Removal 5-13 Assembling Cleaning and Inspecting Installation 4-37 Assembling 5-20 LOW TENSION FLYWHEEL MAGNETO IGNITION SYSTEM 9. 9 hp -1974- 76 15 hp --1974-76 1 .. hp --1973 20 hp -1973 25 hp --1973-76 35 hp --1976 40 hp --1 974-76 40 hp Comm. -1981- 83 5-26 Description 5-26 Theory of Operation 5-27 Troubleshooting 5-27 Removal 5-32 Cleaning and Inspec ting 5-36 Assembling 5-36 TYPE I CAPACITOR DISCHARGE (CD) FLYWHEEL MAGNETO WITH TIMER BASE 50 hp -1971- 75 55 hp --1976-77 5-41 Description 5-41 Theory of Operation 5-41 Troubleshooting 5-42 Servicing 5-48 Stator and Charge Coil Replacement 5-48 Timer Base and Sensor Assembly Replacement 5-49 Power Pack Replacement 5-50 Timing Check and Adjustment 5-51 TYPE II CD FLYWHEEL MAGNETO IGNITION WITH SENSOR COIL 2.5 hp -1987 & on 4 hp Dlx. --1984 & on 4.5 hp -1 980-85 5 hp --1984-85 6 hp -1977- 79 6 hp -1 98 2 & on 7.5 hp -1980- 85 8 hp --1984 & on 9.9 hp -1 977 & on 15 hp --1 977 & on 20 hp -1981 & on 25 hp --1977 & on 30 hp -1 985 & on 35 hp --1977-84 40 hp -1 984 & on 50 hp --1 97 8 & on 55 hp -1978- 83 60 hp -1980- 85 5-51 Description 5-51 Theory of Operation 5-52 Troubleshooting 5-54 Checking Type II System 5-55 Flywheel Removal 5-64 Armature Plate Removal 5-65 Armature Pia te Installation 5-65 Charge or Sensor Coil Removal 5-66 Charge or Sensor Coil Installation 5-67 Charge or Sensor Coil Adjustment 5-67 Flywheel Installation 5-68 Power Pack Replacemen t 5-69 Timing Check Adjustment 5-69 SYNCHRONIZATION FUEL AND IGNITION SYSTEMS 5-70 Primary Pickup Adjustments and Locations 5-70 The No. A Location 5-71 The No. B Location 5-71 The No. C Location 5-72 The No. D Location The No. E Location 5-75 6 ELECTRICAL INTRODUCTION 6-1 BATTERIES 6-1 Marine Batteries 6-1 Battery Construe tion 6-2 Battery Ratings 6-2 Battery Location 6-2 Battery Service 6-2 Jumper Cables 6-5 Storage 6-5 Dual Battery lnstalla tion 6-5 GAUGES AND HORNS 6-7 Constant Voltage System 6-7 Temperature Gauges 6-7 Warning Lights 6-7 Thermomelt Sticks 6-8 FUEL SYSTEM 6-8 Fuel Gauge 6-8 Fuel Gauge Hookup 6-8 Fuel Gauge Troubleshooting 6-9 TACHOMETER 6-10 HORNS 6-10 ELECTRICAL SYSTEM GENERAL INFORMATION 6-11 GENERATING CHARGING CIRCUIT SERVICE 6-12 Troubleshooting 6-13 Removal and Disassembling 6-16 Armature Testing 6-17 Cleaning and Inspecting 6-18 Assembling 6-20 6 ELECTRICAL (CONT) PUSHBUTTON TYPE SHIFT BOX SERVICE --EVINRUDE ONLY 7-14 ALTERNATOR CHARGING Troubleshooting 7-15 CIRCUIT SERVICE 6-22 Disassembling 7-17 Trqubleshooting 6-22 Cleaning and Inspecting 7-18 CHOKE CIRCUIT SERVICE 6-26 Assembling 7-18 STARTER MOTOR SINGLE-LEVER REMOTE CIRCUIT SERVICE 6-26 CONTROL SHIFT BOX 7-20 Circuit Description 6-26 Troubleshooting 7-21 Starter Motor Description 6-26 Disassembling 7-22 Testing 6-28 Assembling 7-23 SHIFT BOX REPAIR 7-26 STARTER DRIVE GEAR SERVICE 6-30 Disassembling 7-26 Disassembling Type I 6-30 Cleaning and Inspecting 7-27 Cleaning and Inspecting 6-31 Assembling 7-27 Assembling Type I 6-32 Disassembling Type II 6-32 CABLE END FITTING INSTALLATION Cleaning and Inspecting 6-32 AT THE ENGINE END FOR ALL Assembling Type II 6-32 SHIFT BOXES EXCEPT SINGLE LEVER REMOTE CONTROL 7-29 BOSCH STARTER MOTOR SERVICE6-33 Removal 6-33 8 LOWER UNIT Disassembling 6-34 Armature Testing 6-34 DESCRIPTION 8-1 Cleaning and Inspecting 6-35 Chapter Coverage 8-2 Assembling 6-37 Illustrations 8-3 PROPELLER SERVICE 8-3 PRESTOLITE SERVICE 6-40 Propeller with Shear Pin 8-3 Removal 6-40 Removal 8-3 Disassembling 6-41 Exhaust Pro peller 8-4 Armature Testing 6-42 Removal 8-5 Cleaning and Inspecting 6-44 Propeller with Shear Pin Assembling 6-44 Installation 8-5 STARTER MOTOR TESTING 6-45 Exhaust Propeller Installation 8-6 STARTER MOTOR INSTALLATION 6-46 LOWER UNIT LUBRICATION 8-7 Draining 8-7 7 REMOTE CONTROLS Filling 8-8 INTRODUCTION 7-1 NO SHIFT LOWER UNIT SERVICE SHIFT BOXES 7-1 1.25 to 4.0 HP 1971 & on 8-8 DOUBLE-LEVER SHIFT Description 8-8 BOX SERVICE 7-3 Troubleshooting 8-9 Troubleshooting Removal 8-9 Removal Water Pump Removal Disassembling 7-5 Lower Unit Disassembling Cleaning and Inspecting Cleaning and Inspecting Assembling ELECTRIC GEAR BOXES AND Assembling 8-13 Water Pump Installation SINGLE LEVER CONTROL 7-8 Troubleshooting 7-8 SINGLE LEVER SHIFT BOX SERVICE JOHNSON UNITS ONLY 7-10 Disassembling 7-10 Cleaning and Inspecting 7-1 1 Assembling 7-12 Lower Unit Installation 8-15 Filling Lower Unit 8-16 Propeller Installation 8-16 SHIFT WITH NO DISCONNECT 4 DELUX THRU 8 HP 1980-'85 8-17 Description 8-17 Removal 8-18 Water Pump Disassembling Lower Unit Disassembling Cleaning and Inspecting Lower Unit Assembling Water Pump Installation Lower Unit Installation Func tiona! Check TROUBLESHOOTING MANUAL SHIFT 6.0 to 40 HP ALL MODELS EXCEPT 35 HP WITH PROPELLER EXHAUST LOWER UNIT SERVICE MANUAL SHIFT 6.0 HP 1971-79 9.5 HP to 20 HP --1971-73 25 HP 1971-85 Shift Rod Disconnec t Lower Unit Removal Water Pump Removal Lower Unit Disassembling Cleaning and Inspecting Lower Unit Assembling Water Pump Installation Lower Unit Installation Functional Check LOWER UNIT SERVICE MANUAL SHIFT 40 HP THRU 1976 Lower Unit Removal Water Pump Removal Lower Unit Disassembling Cleaning and Inspecting Lower Unit Assembling Water Pump Installation Lower Unit Installation Func tiona! Check PROPELLER EXHAUST MECHANICAL SHIFT 9.9 HP 1974 &: on 15 HP 1 97 4 &: on Description Troubleshooting Lower Unit Removal Water Pump Removal Lower Unit Disassembling Cleaning and Inspecting Lower Unit Assembling Water Pump Installation Lower Unit Installation Functional Check 8-18 8-19 8-23 8-26 8-33 8-34 8-35 8-35 8-39 8-39 8-40 8-41 8-42 8-44 8-48 8-52 8-53 8-55 8-56 8-56 8-57 8-57 8-60 8-64 8-67 8-68 8-69 8-70 8-70 8-70 8-72 8-73 8-73 8-77 8-80 8-86 8-87 8-88 PROPELLER EXHAUST MECHANICAL SHIFT 35 HP 1976-84 20 HP 1 974 &: on 25 HP 1986 &: on 30 HP 1981 &: on Description Troubleshooting Lower Unit Removal Water Pump Removal Lower Unit Disassembling Cleaning and Inspecting Lower Unit Assembling Water Pump Installation Lower Unit Installation Func tiona! Check ELECTRIC SHIFT TWO SOLENOIDS 50 HP 1971-72 Description Troubleshooting Lower Unit Removal Water Pump Removal "Frozen" Propeller Shaft Cleaning and Inspecting Lower Unit Assembling Water Pump Installation Lower Unit Installation Functional Check MECHANICAL SHIFT HYDRAULIC ASSIST SHIFT DISCONNECT UNDER LOWER CARBURETOR 50 HP 1973-74 Description Troubleshooting Lower Unit Removal Water Pump Removal "Frozen" Propeller Shaft Cleaning and Inspecting Lower Unit Assembling Water Pump Installation Lower Unit Installation Func tiona! Check MECHANICAL SHIFT SHIFT DISCONNECT UNDER LOWER CARBURETOR 40 HP 1977 &: on 50 HP 1972-73 50 HP 197 5 and 1980 &: on 55 HP 1975-83 60 HP 1 980 &: on Description Troubleshooting 8-88 8-88 8-88 8-91 8-93 8-93 8-99 8-100 8-1 10 8-1 12 8-1 14 8-114 8-114 8-1 15 8-1 17 8-1 18 8-121 8-125 8-127 8-137 8-140 8-141 8-142 8-1'"'2 8-142 8-145 8-145 8-148 8-156 8-156 8-167 8-170 8-171 8-171 8-171 8-171 8 LOWER UNIT (CONTI Starter Disassembling 9-27 Cleaning and Inspecting 9-29 Lower Unit Removal 8-173 Assembling 9-29 Water Pump Removal 8-175 Installation 9-30 "frozen" Propeller Shaft 8-178 Adjustment 9-31 Cleaning and Inspecting 8-182 Lower Unit Assembling 8-185 TYPE V MOUNTED A TOP Water Pump Installation 8-193 FLYWHEEL WITH NO Lower Unit Installation 8-196 RETURN SPRINGS "FROZEN" PROPELLER 8-197 40 HP --1971-76 & 1981-85 9-32 Removal 9 HAND STARTERS Cleaning and Inspecting Assembling 9-36 INTRODUCTION 9-1 Rope Installation Emergency Starting 9-3 TYPE I STARTER CYLINDER WITH PINION GEAR All 5 HP All6 HP All 7.5 HP All8 HP 9-4 Starter Rope Replacement 9-4 Removal 9-4 Installation 9-5 Starter Removal 9-5 Disassembling 9-7 Starter Installation 9-39 TYPE VI MOUNTED A TOP FLYWHEEL WITH ONE OR TWO NYLON PAWLS COLT, JUNIOR, & ULTRA 1986 & on 2 HP 1971-85 2.5 HP 1987 & on 4 HP 1980 & on 18 HP 1971-73 20 HP 1971-73, 1985 & on 25 HP 1971 & on Cleaning and Inspecting 35 HP 1976-84 9-41 Assembling 9-8 Starter Removal 9-41 Disassembling 9-41 TYPE II STARTER Cleaning and Inspecting 9-43 CYLINDER WITH PINION GEAR Starter Assembling 9-44 All 9.5 HP 9-11 Rope Installation 9-4'-J. Rope Removal 9-11 Starter Installation 9-48 Rope Installation 9-12 Starter Removal 9-12 Cleaning and Inspecting 9-14 TYPE VII MOUNTED ATOP FLYWHEEL Assembling 9-15 WITH LARGE PAWL PLATE Installation 9-15 Starter Removal 9-48 Disassembling 9-48 TYPE III STARTER Cleaning and Inspecting 9-49 COIL SPRING WITH SWING ARM Starter Assembling 9-49 VERTICAL MOUNT Starter Installation 9-50 4 HP 1971-78 4 HP DELUX 1982 & on 4.5 HP 1980-84 9-17 Removal 9-17 Disassembling 9-18 Cleaning and Inspecting 9-19 10 POWER TRIM/TILT Assembling 9-20 SYSTEM DESCRIPTION 10-1 TYPE IV STARTER FILLING SYSTEM 10-2 COIL SPRING WITH SLIDING GEAR TROUBLESHOOTING 10-2 HORIZONTAL MOUNT SERVICING 10-3 All 9.9 HP All 15 HP 9-23 ELECTRICAL MOTOR SERVICE 10-3 Removal 9-23 Cleaning &:: Inspecting 10-4 Starter Rope Replacement 9-24 Testing 10-4 11 MAINTENANCE INTRODUCTION 11-1 ENGINE SERIAL NUMBERS 11-2 FIBERGLASS HULLS 11-3 ALUMINUM HULLS 11-3 BELOW WATERLINE SERVICE 11 -4 SUBMERGED ENGINE SERVICE 11-5 WINTER STORAGE 11-7 LOWER UNIT SERVICE 11-9 Pro pellers 11 -9 BATTERY STORAGE 11-14 PRESEASON PREPARATION 11-15 APPENDIX METRIC CONVERSION CHART A-1 DRILL SIZE CONVERSION CHART A-2 TORQUE SPECIFICATIONS A-3 TUNE-UP SPECIFICATIONS A-4 to A-17 POWERHEAD SPECIFICATIONS A-18 OIL/FUEL MIXTURE A-19 GEAR OIL CAPACITIES A-19 STARTER MOTOR SPECS. A-20 REGULA TOR SPECIFICATIONS A-20 GENERATOR SPECIFICATIONS A-20 CONDENSER SPECIFICATIONS A-21 STARTER ROPE SPECIFICATIONS A-21 WIRE IDENTIFICATION DRAWINGS Typical l-ey linder pwrhd. A-22 2.5 hp, Excel, Ultra, &. 4 hp -1984 &. on A-23 4 Delux thru 55 hp w/CD II Ign., w /manual start; Also models equipped with A.C. lighting A-24 9.9 hp and 15 hp w/electric start --1974-76 A-25 9.9 hp and 15 hp wIelectric start --1977-85 A-26 9.9 hp and 15 hp w/electric start --1986 &. on A-27 18 hp, 20 hp, &. 25 hp wIelectric start --1971-72 A-28 18 hp, 20 hp, &. 25 hp w/e1ectric start --1973-76 A-29 35 hp w/electric start --1976 A-30 25 hp and 35 hp --1977-78 A-31 20 hp thru 40 hp w/std. shift &. wIelectric start 1979-85 A-32 40 hp w/generator, w/std. shift &. w/electric start --1971-73 A-33 40 hp w/alternator, w/std. shift &. w/electric start --1974-76 A-34 50 hp w Ialtern a tor &. w/electric start --1971-72 A-35 50 hp w Ialternator &. w/electric start --1973-77 Also 55 hp with no thermo switch -1977 A-36 50 hp w/manual Start --1980-85 A-37 55 hp w/electric start --1977 A-38 50 hp &. 55 hp w/electric start --1978 A-39 50 hp --1 979, 55 hp --1979-83, &. 60 hp --1 980-81 all w Ielectric start A-40 20 hp, 25 hp, 30 hp, 35 hp, 40 hp, 50 hp, and 60 hp w/remote electric start - 1982-85 A-41 40 hp &. 50 hp w I tiller electric start --1986 &. on A-42 40 hp &. 50 hp w/remote electric start --1986 &. on A-43 Remote Control Box A-44 1 SAFETY 1-1 INTRODUCTION Today, a boat and power unit represents a sizeable investment for the owner. In order to protect this investment and to receive the maximum amount of enjoyment from the boat, it must be cared for properly while being used and when it is out of the water. Always store the boat with the bow higher than the stern and be sure to remove the transom drain plug and the inner hull drain plugs. If any type cover is used to protect the boat, plastic, canvas, whatever, be sure to allow for some movement of air through the hull. Proper ventilation will assure evaporation of any condensation due to changes in temperature and humidity. 1-2 CLEANING, WAXING, AND POLISHING An outboard boat should be washed with clear water after each use to remove surface dirt and any salt deposits from use in salt water. Regular rinsing will extend the time between waxing and polishing. It will also give you "pride of ownership", by having a sharp looking piece of equipment. Elbow grease, a mild detergent, and a brush will be required to remove stubborn dirt, oil, and other unsightly deposits. Stay away from harsh abrasives or strong chemical cleaners. A white buffing compound can be used to restore the original gloss to a scratched, dull, or faded area. The finish of your boat should be thoroughly cleaned, buffed, and polished at least once each season. Take care when buffing or polishing with a marine cleaner not to overheat the surface you are working, because you will burn it. A small outboard engine mounted on an aluminum boat should be removed from the boat and stored separately. Under all circumstances, any outboard engine must ALWAYS be stored with the power head higher than the lower unit and exhaust system. This position will prevent water trapped in the lower unit from draining back through the exhaust ports into the powerhead. Lower unit badly corroded_because the zinc was not Whenever the boat is stored, for long or short replaced. Once the zinc is destroyed, more costly parts periods, the bow should be slightly higher than the stern will be damaged. Attention to the zinc condition is and the drain plug in the transom removed to ensure extre[Tlely important during boat operation in salt proper drainage of rain water. water. 1-2 SAFETY A new zinc prior to installation. This inexpensive item will save corrosion on more valuable parts. Most outboard engines have a flat area on the back side of the powerhead. When the engine is placed with the flat area on the powerhead and the lower unit resting on the floor, the engine will be in the proper altitude with the powerhead higher than the lower unit. 1-3 CONTROLLINGCORROSION Since man first started out on the water, corrosion on his craft has been his enemy. The first form was merely rot in the wood and then it was rust, followed by other forms of destructive corrosion in the more modern materials. One defense against corrosion is to use similar metals throughout the boat. Even though this is difficult to do in designing a new boat, particularily the undersides, similar metals should be used whenever and wherever possible. A second defense against corrosion is to insulate dissimilar metals. This can be done by using an exterior coating of Sea Skin or by insulating them with plastic or rubber gaskets. Using Zinc The proper amount of zinc attached to a boat is extremely important. The use of too much zinc can cause wood burning by placing the metals close together and they become "hot". On the other hand, using too small a zinc plate will cause more rapid deterioration of the the metal you are trying to protect. If in doubt, consider the fact that it is far better to replace the zincs than to replace planking or other expensive metal parts from having an excess of zinc. When installing zinc plates, there are two routes available. One is to install many different zincs on all metal part.. and thus run the risk of wood burning. Another route, is to use one large zinc on the transom of the boat and then connect this zinc to every underwater metal part through internal bonding. Of the two choices, the one zinc on the transom is the better way to go. Small outboard engines have a zinc plate attached to the cavitation plate. Therefore, the zinc remains with the engine at all times. 1-4 PROPELLERS As you know, the propeller is actudlly what moves the boat through the water. This is how it is done. The propeller operates in water in much the manner as a wood screw does in wood. The propeller "bites" into the water as it rotates. Water passes between the blades and out to the rear in the sha pe of a cone. The pro peller ''biting" through the water in much the same manner as a wood auger is what propels the boat. Diameter and pitch are the two basic dimensions of a propeller. The diameter is measured across the circumference of a circle scribed by the propeller Propeller and associated parts in order, washer, blades, as shown. shear pin, and nut, ready for installation. PROPELLERS 1-3 Diagram to explain the pitch dimension of a propeller. The pitch is the theoretical distance a propeller would travel through the water if there was no slippage. Arrangement of propeller and associated parts, in order, for a small horsepower engine. Diameter and Pitch Only two dimensions of the propeller are of real interest to the boat owner: the diameter and the pitch. These two dimensions are stamped on the propeller hub and always appear in the same order: the diameter first and then the pitch. For instance, the number 15-19 stamped on the hub, would mean the propeller had a diameter of 15 inches with a pitch of 19. The diameter is the measured distance from the tip of one blade to the tip of the other as shown in the accompanying illustration. The pitch of a propeller is the angle at which the blades are attached to the hub. This figure is expressed in inches of water travel for each revolution of the propeller. In our example of a 15-19 propeller, the propeller should travel 19 inches through the water each time it revolves. If the propeller action was perfect and there was no slippage, then the pitch multiplied by the propeller rpms would be the boat speed. Most outboard manufacturers equip their units with a standard propeller with a diameter and pitch they consider to be best sui ted to the engine and the boat. Such a propeller allows the engine to run as near to the rated rpm and horsepower (at full throttle) as possible for the boat design. The blade area of the propeller determines its load-carrying capacity. A twoblade propeller is used for high-speed running under very light loads. Shear pin installed behind the propeller instead of in front of the propeller. A four-blade propeller is installed in boats intended to operate at low speeds under very heavy loads such as tugs, barges, or large houseboats. The three-blade propeller is the happy medium covering the wide range between the high performa'nce units and the load carrying workhorses. Propeller Selection There is no standard propeller that will do the proper job in very many cases. The list of sizes and weights of boats is almost endless. This fact coupled with the many boat-engine combinations makes the propeller selection for a specific purpose a difficult job. In fact, in many cases the propeller is changed after a few test runs. Proper selection is aided through the use of charts set up for various engines and boats. These charts should be studied and understood when buying a propeller. However, bear in mind, the charts are based on average boats 21" 1-4 SAFETY with average loads, therefore, it may be necessary to make a change in size or pitch, in order to obtain the desired results for the hull design or load condition. A wide range of pitch is available for each of the larger horsepower engines. The choice available for the smaller engines, up to about 25 hp, is restricted to one or two sizes. Remember, a low pitch takes a smaller bite of the water than the high pitch propeller. This means the low pitch propeller will travel less distance through the water per revolution. The low pitch will require less horsepower and will allow the engine to run faster and more efficiently. It stands to reason, and it's true, that the high pitch propeller will require more horsepower, but will give faster boat speed if the engine is allowed to turn at its rated rpm. If a higher-pitched propeller is installed on a boat, in an effort to get more speed, extra horsepower will be required. If the extra power is not available, the rpms will be reduced to a less efficient level and the actual boat speed will be less than if the lower-pitched propeller had been left installed. All engine manufacturers design their units to operate with full throttle at, or slightly above, the rated rpm. If you run your engine at the rated rpm, you will increase spark plug life, receive better fuel economy, and obtain the best performance CAVITATION BURN 0 00 0 from your boat and engine. Therefore, take time to make the proper propeller selection for the rated rpm of your engine at full throttle with what you consider to be an average load. Your boat will then be correctly balanced between engine and propeller throughout the entire speed range. A reliable tachometer must be used to measure engine speed at full throttle to ensure the engine will achieve full horse power and operate efficiently and safely. To test for the correct propeller, make your run in a body of smooth water with the lower unit in forward gear at full throttle. Observe the tachometer at full throttle. NEVER run the engine at a high rpm when a flush attachment is installed. If the reading is above the manufacturer's recommended operating range, you must try propellers of greater pitch, until you find the one that allows the engine to operate continually within the recommended full throttle range. If the engine is unable to deliver top performance and you feel it is properly tuned, then the propeller may not be to blame. Operating conditions have a marked effect on performance. For instance, an engine will lose rpm when run in very cold water. It will also lose rpm when run in salt water as compared with fresh water. A hot, low-barometer day will also cause your engine to lose power. Cavitation (air bubbles) formed at the propeller. A corroded hub on a small engine propeller. ReManufacturers are constantly fighting this problem, as placement of this propeller will be less expensive than explained in the text. the cost of a rebuild. Ventilation Ventilation is the forming of voids in the water just ahead of the propeller blades. Marine propulsion designers are constantly fighting the battle against the formation of these voids due to excessive blade tip speed and engine wear. The voids may be filled with air or water vapor, or they may actually be a partial vacuum. Ventilation may be caused by installing a piece of equipment too close to the lower unit, such as the knot indicator pickup, depth sounder, or bait tank pickup. Vibration Your propeller should be checked regularly to be sure all blades are in good condition. If any of the blades become bent or nicked, this condition will set up vibrations in the drive unit and the motor. If the vibration becomes very serious it will cause a loss of power, efficiency, and boat performance. If the vibration is allowed to continue over a period of time it can have a damaging effect on many of the operating parts. Vibration in boats can never be completely eliminated, but it can be reduced by keeping all parts in good working condition and through proper maintenance and lubrication. Vibration can also be reduced in some cases by increasing the number of blades. For this reason, many racers use PROPELLERS 1-5 two-blade props and luxury cruisers have four-and five-blade props installed. Shock Absorbers The shock absorber in the propeller plays a very important role in protecting the shafting, gears, and engine against the shock of a blow, should the propeller strike an underwater object. The shock absorber allows the propeller to stop rotating at the instant of impact while the power train continues turning. How much impact the propeller is able to withstand before causing the clutch hub to slip is calculated to be more than the force needed to propel the boat, but less than the amount that could damage any part of the power train. Under normal propulsion loads of moving the boat through the water, the hub will not slip. However, it will slip if the propeller strikes an object with a force that would be great enough to stop any part of the power train. I 0° RAKE Rubber hub removed from a propeller. This hub was fllustration depicting the rake of a propeller, as removed because the hub was slipping in the propeller. explained in the text. Comparison of a constant and progressive pitch propeller. Notice how the pitch of the progressive pitch propeller, right, changes to give the blade more thrust and therefore, the boat more speed. 1-6 SAFETY If the power train was to absorb an impact great enough to stop rotation, even for an instant, something would have to give and be damaged. If a propeller is subjected to repeated striking of underwater objects, it would eventually slip on its clutch hub under normal loads. If the propeller would start to slip, a new hub and shock absorber would have to be installed. Propeller Rake If a propeller blade is examined on a cut extending directly through the center of the hub, and if the blade is set vertical to the propeller hub, as shown in the accompanying illustration, the propeller is said to have a zero degree (0°) rake. As the blade slants back, the rake increases. Standard propel- o 0 lers have a rake angle from 0 to 15 • A higher rake angle generally improves propeller performance in a cavitating or ventilating situation. On lighter, faster boats, higher rake often will increase performance by holding the bow of the boat higher. Progressive Pitch Progressive pitch is a blade design innovation that improves performance when forward and rotational speed is high and/ or the propeller breaks the surface of the water. Progressive pitch starts low at the leading edge and progressively increases to the trailing edge, as shown in the accompanying illustration. The average pitch over the entire blade is the number assigned to that propeller. In the illustration of the progressive pitch, the average pitch assigned to the propeller would be 21. Propeller with a "cupped" leading edge. "Cupping" gives the propeller a better "hold" in the water. Cupping If the propeller is cast with a edge curl inward on the trailing edge, the blade is said to have a cup. In most cases, cupped blades improve performance. The cup helps the blades to "HOLD" and not break loose, when operating in a cavi.tating or ventilating situation. This action permits the engine to be trimmed out further, or to be mounted higher on the transom. This is especially true on high-performance boats. Either of these two adjustments will usually add to higher speed. CONSTANT PITCH PROGRESSIVE-PITCH The cup has the effect of adding to the propeller pitch. Cupping usually will reduce full-throttle engine speed about 150 to 300 rpm below the same pitch propeller without a cup to the blade. A propeller re pair sho p is able to increase or decrease the cup on the blades. This change, as explained, will alter engine rpm to meet specific operating demands. Cups are rapidly becoming standard on propellers. In order for a cup to be the most effective, the cup should be completely concave (hollowed) and finished with a sharp corner. If the cup has any convex rounding, the effectiveness of the cup will be reduced. Rotation Pro pellers are manufactured as righthand rotation (RH), and as left-hand rotation (LH). The standard propeller for outboards is RH rotation. A right-hand propeller can easily be identified by observing it as shown in the accompanying illustration. Observe how the blade slants from the lower left toward the upper right. The left-hand propeller slants in the opposite direction, from upper left to lower right, as shown. When the propeller is observed rotating from astern the boat, it will be rotating clockwise when the engine is in forward gear. The left-hand propeller will rotate counterclockwise. Propeller Modification If poor acceleration is experienced on hard-to-plane boats, or-..-tc suggests a slight modification be performed. The modification involves drilling three 6 mm (7/32") COUNTERCLOCKW ISE OR LEFT HAND CLOCKW ISE OR RI GHT HAND Right-and left-hand propellers showing how the angle of the blades is reversed. Right-hand propellers are by far the most popular. PROPELLERS 1-7 holes through the outer shell in a precise pattern. The holes allow exhaust gasses to bleed onto the propeller blades causing controlled ventilation during the acceleration period. This action will allow the motor to turn at a higher rpm under acceleration, thus providing more power to plane the boat. Layout the exact position of each hole 16 ±2mm (5/8" .±.1/16") back from the inner lip and the same amount in a CLOCKWISE direction from the base of each blade, as shown in the accompanying illustration. If an inner rib is located under the position of any one of the holes, another propeller must be used. If the holes are properly positioned, and the correct size is drilled, there will be no affect on top speed, maximum rpm, or ventilation in turns. Im proper location or size holes will have no affect on performance, particularly in turns. 1-5 FUEL SYSTEM With Built-in Fuel Tank All parts of the fuel system should be selected and installed to provide maximum service and protection against leakage. Reinforced flexible sections should be installed in fuel lines where there is a lot of motion, such as at the engine connection. The flaring of copper tubing should be annealed after it is formed as a protection against harden ing. CAUTION: Compression fittings should NOT be used because they are so easily overtightened, which places them under a strain and subjects them to fatigue. Layout for drilling three holes through the propeller shell for increased performance to provide more power to plane the boat, as explained in the text. 1-8 SAFETY Such conditions will cause the fitting to leak after it is connected a second time. The capacity of the fuel filter must be large enough to handle the demands of the engine as specified by the engine manufacturer. A manually-operated valve should be installed if anti-siphon protection is not provided. This valve should be installed in the fuel line as close to the gas tank as possible. Such a valve will maintain anti-siphon protection between the tank and the engine. The supporting surfaces and hold-downs must fasten the tank firmly and they should be insulated from the tank surfaces. This insulation rna terial should be non-abrasive and nonabsorbent material. Fuel tanks installed in the forward portion of the boat should be especially well secured and protected because shock loads in this area can be as high as 20 to 25 g's ("g" equals force of gravity). Static Electricity In very simple terms, static electricity is called frictional electricity. It is generated by two dissimilar materials moving over each other. One form is gasoline flowing through a pipe or into the air. Another form is when you brush your hair or walk across a synthetic carpet and then touch a metal object. All of these actions cause an electrical charge. In most cases, static electricity is generated during very dry weather conditions, but when you are filling the fuel tank on a boat it can happen at any time. Fuel Tank Grounding One area of protection against the buildup of static electricity is to have the fuel A three-position valve permits fuel to be drawn from either tank or to be shut off completely. Such an arrangement prevents accidental siphoning of fuel from the tank. Old style pressure-type tank showing the fuel line to the engine and quick-disconnect fitting. tank properly grounded (also known as bonding). A direct metal-to-metal contact from the fuel hose nozzle to the water in which the boat is floating. If the fill pipe is made of metal, and the fuel nozzle makes a good contact with the deck plate, then a good ground is made. As an economy measure, some boats use rubber or plastic filler pipes because of compound bends in the pipe. Such a fill line does not give any kind of ground and if your boat has this type of installation and you do Adding fuel to a six-gallon OMC fuel tank. Some fuel must be in the tank before oil is added to prevent the oil from accumulating on the tank bottom. not want to replace the filler pipe with a metal one, then it is possible to connect the deck fitting to the tank with a copper wire. The wire should be 8 gauge or larger. The fuel line from the tank to the engine should provide a continuous metal-to-metal contact for proper grounding. If any part of this line is plastic or other non-metallic material, then a copper wire must be connected to bridge the non-metal material. The power train provides a ground through the engine and drive shaft, to the propeller in the water. Fiberglass fuel tanks pose problems of their own. One method of grounding is to run a copper wire around the tank from the fill pipe to the fuel line. However, such a wire does not ground the fuel in the tank. Manufacturers should imbed a wire in the fiberglass and it should be connected to the intake and the outlet fittings. This wire would avoid corrosion which could occur if a wire passed through the fuel. CAUTION: Itis not advisable to use a fiberglass fuel tank if a grounding wire was not installed.. Anything you can feel as a "shock" is enough to set off an explosion. Did you know that under certain atmospheric conditions you can cause a static explosion yourself, particularly if you are wearing synthetic clothing. It is almost a certainty you could cause a static spark if you are NOT wearing insulated rubber-soled shoes. As soon as the deck fitting is opened, fumes are released to the air. Therefore, to be safe you should ground yourself before A fuel tank properly grounded to prevent static electricity. Static electricity could be extremely dangerous when taking on fuel. LOADING 1-9 opening the fill pipe deck fitting. One way to ground yourself is to dip your hand in the water overside to discharge the electricity in your body before opening the filler cap. Another method is to touch the engine block or any metal fitting on the dock which goes down into the water. 1-6 LOADING In order to receive maximum enjoyment, with safety and performance, from your boat, take care not to exceed the load capacity given by the manufacturer. A plate attached to the huJI indicates the U.S. Coast Guard capacity information in pounds for persons and gear. If the plate states the maximum person capacity to be 750 pounds and you assume each person to weigh an average of 150 lbs., then the boat could carry five persons safely. If you add anoth er 250 lbs. for motor and gear, and the maximum weight capacity for persons and gear is 1,000 lbs. or more, then the five persons and gear would be within the limit. Try to load the boat evenly port and starboard. If you place more weight on one side than on the other, the boat will list to the heavy side and make steering difficult. You will also get better performance by placing heavy supplies aft of the center to keep the bow light for more efficient planing. U.S. COAST GUARD MAXIMUM CAPACITIES PERSONS OR LBS LBS PERSONS,MOTOR,GEAR H.P.MOTOR THIS BOAT COMPLIES WITH U.S. COAST GUARD SA FETY STANDARDS IN EF FECT ON THE DATE OF CERTI FICATION RECREATIONAL ENTERPRISES RIAL TO, CALIF . U.S. Coast Guard plate affixed to all new boats. When the blanks are filled in, the plate will indicate the Coast Guard's recommendations for persons, gear, and horsepower to ensure safe operation of the boat. These recommendations should not be exceeded, as explained in the text. 1-10 SAFETY Clarif ication Much confusion arises from the terms, certification, requirements, approval, regulations, etc. Perhaps the following may clarify a c<;>uple of these points. 1-The Coast Guard does not approve boats in the same manner as they "Approve" life jackets. The Coast Guard applies a formula to inform the public of what is safe for a particular craft. 2-If a boat has to meet a particular regulation, it must have a Coast Guard certification plate. The public has been led to believe this indicates approval of the Coast Guard. Not so. 3-The certification plate means a willingness of the manufacturer to meet the Coast Guard regulations for that particular craft. The manufacturer may recall a boat if it fails to meet the Coast Gtmrd requirements. 4-The Coast Guard certification plate, see accompanying illustration, may or may not be metal. The plate is a regulation for the manufacturer. It is only a warning plate and the public does not have to adhere to the restrictions set forth on it. Again, the plate sets forth information as to the Coast Guard's opinion for safety on that particular boat. Type I PFD Coast Guard Approved life jacket. This type flotation device provides the greatest amount of buoyancy. NEVER use them for cushions or other purposes. 5-Coast Guard Approved equipment is equipment which has been approved by the Commandant of the U.S. Coast Guard and has been determined to be in compliance with Coast Guard specifications and regulations relating to the materials, construction, and performance of such equipment. 1-7 HORSEPOWER The maximum horsepower engine for each individual boat should not be increased by any great amount without checking requirements from the Coast Guard in your area. The Coast Guard determines horsepower requirements based on the length, beam, and depth of the hull. TAKE CARE NOT to exceed the maximum horsepower listed on the plate or the warranty and possibly the insurance on the boat may become void. 1-8 FLOTATION If your boat is less than 20 ft. overall, a Coast Guard or BIA (Boating Industry of America) now changed to NMMA (National Marine Manufacturers Association) requirement is that the boat must have buoyant material built into the hull (usually foam) to keep it from sinking if it should become swamped. Coast Guard requirements are mandatory but the NMMA is voluntary. "Kept from sinking" is defined as the ability of the flotation material to keep the boat from sinking when filled with water A Type N PFD cushion device intended to be thrown to a person in the water. If air can be squeezed out of the cushion it is no longer fit for service as a PFD. and with passengers clinging to the hull. One restriction is that the total weight of the motor, passengers, and equipment aboard does not exceed the maximum load capacity listed on the plate. Life Preservers -Personal Flotation Devices (PFDs) The Coast Guard requires at least one Coast Guard approved life-saving device be carried on board all motorboats for each person on board. Devices approved are identified by a tag indicating Coast Guard approval. Such devices may be life preservers, buoyant vests, ring buoys, or buoyant cushions. Cushions used for seating are serviceable if air cannot be squeezed out of it. Once air is released when the cushion is squeezed, it is no longer fit as a flotation device. New foa.n cushions dipped in a rubberized material are almost indestructible. Life preservers have been classified by the Coast Guard into five type categories. All PFDs presently acceptable on recreational boats fall into one of these five designations. All PFDs MUST be U.S. Coast Guard approved, in good and serviceable condition, and of an appropriate size for the persons who intend to wear them. Wearable PFDs MUST be readily accessible and throwable devices MUST be immediately available for use. Type I PFD has the greatest required buoyancy and is designed to turn most UNCONSCIOUS persons in the water from a face down position to a vertical or slightly backward position. The adult size device provides a minimum buoyancy of 22 pounds and the child size provides a minimum buoyancy of 11 pounds. The Type I PFD provides the greatest protection to its wearer and is most effective for all waters and conditions. TypeD PFD is designed to turn its wearer in a vertical or slightly backward position in the water. The turning action is not as pronounced as with a Type I. The device will not turn as many different type persons under the same conditions as the Type I. An adult size device provides a minimum buoyancy of 15Yz pounds, the medium child size provides a minimum of 11 pounds, and the infant and small child sizes provide a minimum buoyancy of 7 pounds. FLOTATION 1-1 1 Type Ill PFD is designed to permit the wearer to place himself (herself) in a vertical or slightly backward position. The Type III device has the same buoyancy as the Type II PFD but it has little or no turning ability. Many of the Type III PFD are designed to be particularly useful when water skiing, sailing, hunting, fishing, or engaging in other water sports. Several of this type will also provide increased hypothermia protection. Type IV PFD is designed to be thrown to a person in the water and grasped and held by the user until rescued. It is NOT designed to be worn. The most common Type IV PFD is a ring buoy or a buoyant cushion. Type V PFD is any PFD approved for restricted use. Coast Guard regulations state, in general terms, that on all boats less than 16 ft. overall, one Type I, II, III, or IV device shall be carried on board for each person in the boat. On boats over 26 ft., one Type I, II, or III device shall be carried on board for each person in the boat plus one Type IV device. It is an accepted fact that most boating people own life preservers, but too few actually wear them. There is little or no excuse for not wearing one because the modern comfortable designs available today do not subtract from an individual's boating pleasure. Make a life jacket available to Type IV P F D ring buoy designed to be thrown.. On ocean cruisers, this type device usually has a weighted pole with flag, attached to the buoy. 1-12 SAFETY your crew and advise each member to wear it. If you are a crew member ask your skipper to issue you one, especially when boating in rough weather, cold water, or when runn ing at high speed. Naturally, a life jacket should be a must for non-swimmers any time they are out on the water in a boat. 1-9 EMERGENCY EQUIP MENT Visual Distress Signals The Regulation Since January 1, 1981, Coast Guard Regulations require all recreation boats when used on coastal waters, which includes the Great Lakes, the territorial seas and those waters directly connected to the Great Lakes and the territorial seas, up to a point where the waters are less than two miles wide, and boats owned in the United States when operating on the high seas to be equipped with visual distress signals. The only exceptions are during daytime (sunrise to sunset) for: Recreational boats less than 16 ft. (5meters) in length. Boats participating in organized events such as races, regattas or marine parades. Open sailboats not equipped with propulsion machinery and less than 26 ft. (8 meters) in length. Manually propelled boats. The above listed boats need to carry night signals when used on these waters at night. Pyrotechnic visual distress signaling devices MUST be Coast Guard Approved, in serviceable condition and stowed to be readily accessible. If they are marked with a date showing the serviceable life, this date must not have passed. Launchers, produced before Jan. 1, 1981, intended for use with approved signals are not required to be Coast Guard Approved. USCG Approved pyrotechnic visual distress signals and associated devices include: Pyrotechnic red flares, hand held or aerial. Pyrotechnic orange smoke, hand held or floating. Launchers for aerial red meteors or parachute flares. Moisture-protected flares should be carried on board for use as a distress signal. Internationally accepted distress signals. Non-pyrotechnic visual distress signaling devices must carry the manufacturer's certification that they meet Coast Guard requirements. They must be in serviceable condition and stowed so as to be readily accessible. This group includes: Orange distress flag at least 3 x 3 feet with a black square and ball on an orange background. Electric distress light --not a flashlight but an approved electric distress light which MUST automatically flash the international SOS distress signal ( •) four to six times each minute. Types and Quanti ti es The following variety and combination of devices may be carried in order to meet the require :nen ts. l-Three hand-held red flares (day and night). 2-One electric distress light (night on ly). 3-One hand-held red flare and two parachute flares (day and night). 4-One hand-held orange smoke signal, two floating orange smoke signals (day) and one electric distress light (day and night). If young children are frequently aboard your boat, careful selection and proper stowage of •tisual distress signals becomes especially important. If you elect to carry pyrotechnic devices, you should select those in tough packaging and not easy to ignite should the devices fall into the hands of children. Coast Guard Approved pyrotechnic devices carry an expiration date. This date can NOT exceed 42 months from the date of EMERGENCY EQUIPMENT 1-13 manufacture and at such time the device can no longer be counted toward the minimum requirements. SPECIAL WORDS In some states the launchers for meteors and parachute flares may be considered a firearm. Therefore, check with your state authorities before acquiring such a launcher. First Aid Kits The first-aid kit is similar to an insurance policy or life jacket. You hope you don't have to use it but if n..eded, you want it there. It is only natural to overlook this essential item because, let's face it, who likes to think of unpleasantness when planning to have only a good time. However, the prudent skipper is prepared ahead of time, and is thus able to handle the emergency without a lot of fuss. Good commercial first-aid kits are available such as the Johnson and Johnson "Marine First-Aid Kit". With a very modest expenditure, a well-stocked and adequate kit can be prepared at home. Any kit should include instruments, supplies, and a set of instructions for their use. Instruments should be protected in a watertight case and should include: scissors, tweezers, tourniquet, thermometer, safety An adequately stocked first-aid kit should be on A sounding device should be mounted close to the board for the safety of crew and guests. helmsperson for use in sounding an emergency alarm. 1-1 4 SAFETY pins, eye-washing cup, and a hot water bottle. The supplies in the kit should include: assorted bandages in addition to the various sizes of "band-aids" , adhesive tape , absorbent cotton, applicators, petroleum jelly, antiseptic (liquid and ointment), local ointment, aspirin, eye ointment, antihistamine, ammonia inhalent, sea-sickness pills, antacid pills , and a laxative. You may want to consult your family physician about including antibiotics. Be sure your kit contains a first-aid manual because even though you have taken the Red Cross course, you may be the patient and have to rely on an untrained crew for care. Fi re Extinguishers All fire extinguishers must bear Under writers Laboratory (UL) "Marine Type" ap proved labels. With the UL certification, the extinguisher does not have to have a Coast Guard approval number. The Coast Guard classifies fire extinguishers according to their size and type. Type B-1 or B-11 Designed for extinguish ing flammable liquids. Required on all mo torboats. The Coast Guard considers a boat having one or more of the following conditions as a "boat of closed construction" subject to fire extinguisher regulations. A suitable fire extinguisher should be mounted close to the helmsman for emergency use. 1-Inboard engine or engines. 2-Closed compartments under thwarts and seats wherein portable fuel tanks may be stored. 3-Double bottoms not sealed to the hull or which are not completely filled with flotation materials. 4-Closed living spaces. 5-Closed stowage compartments in which combustible or flammable material is stored. 6-Permanently installed fuel tanks. Detailed classification of fire extinguishers is by agent and size: B-1 contains 1-1/4-gallons foam, lJ. pounds carbon dioxide, 2 pounds dry chemical, and 2-1/2 pounds freon. B-U contains 2-1/2 gallons foam, 15 pounds carbon dioxide, and 10 pounds dry chemical. The class of motorboat dictates how many fire extinguishers are required on board. One B-II unit can be substituted for two B-I extinguishers. When the engine compartment of a motorboat is equipped · with a fixed (built-in) extinguishing system , one less portable B-I unit is required. Dry chemical fire extinguishers without At least one gallon of emergency fuel should be kept on board in an approved container. gauges or indicating devices must be weighed and tagged every 6 months. If the gross weight of a carbon dioxide fire extinguisher is reduced by more 10% of the net weight, the extinguisher is not accept able and·must be recharged. READ labels on fire extinguishers. If the extinguisher is U.L. listed, it is approved for marine use. DOUBLE the number of fire extinguishers recommended by the Coast Guard, because their requirements are a bare MINIMUM for safe operation. Your boat, family, and crew, must certainly be worth much more than "bare minimum". 1-10 COMPASS Selection The safety of the boat and her crew may depend on her compass. In many areas weather conditions can change so rapidly that within minutes a skipper may find himself "socked-in" by a fog bank, a rain squall, or just poor visibility. Under these conditions, he may have no other means of keeping to his desired course except with the compass. When crossing an open body of water, his compass may be the only means of making an accurate landfall. During thick weather when you can neither see nor hear the expected aids to navigation, attempting to run out the time on a given course can disrupt the pleasure of the cruise. The skipper gains 1i ttle comfort in a chain of soundings that does not match those given on the chart for the expected area. Any stranding, even for a short time, can be an unnerving experience. A pilot will not knowingly accept a cheap parachute. A good boater should not accept a bargain in lifejackets, fire extinguishers, or compass. Take the time and spend the few extra dollars to purchase a compass to fit your expected needs. Regardless of what the salesman may tell you, postpone buying until you have had the chance to check more than one make and model. Lift each compass, tilt and turn it, simulating expected motions of the boat. The compass card should have a smooth and stable reaction. The card of a good quality compass will come to rest without oscillations about the lubber's line. Reasonable movement in your hand, comparable to the rolling and pitching COMPASS 1-15 The compass is a delicate instrument and deserves respect. It should be mounted securely and in position where it can be easily observed by the helmsman. of the boat, should not materially affect the reading. Installation Proper installation of the compass does not happen by accident. Make a critical check of the proposed location to be sure compass placement will permit the helmsman to use it with comfort and accuracy. First, the compass should be placed directly in front of the helmsman and in such a position that it can be viewed without body stress as he sits or stands in a posture of relaxed alertness. The compass should be in the helmsman's zone of comfort. If the compass is too far away, he may have to bend forward to watch it; too close and he must rear backward for relief. Do not hesitate to spend a few extra dollars for a good reliable compass. If in doubt, seek advice from fellow boaters. 1-16 SAFETY Second, give some thought to comfort in heavy weather and poor visibilty conditions during the day and night. In some cases, the compass position may be partially determined by the location of the wheel, shift lever, and· throttle handle. Third, inspect the compass site to be sure the instrument will be at least two feet from any engine indicators, bilge vapor detectors, magnetic instruments, or any steel "Innocent" objects close to the compass, such as diet coke in an aluminum can, may cause serious problems and lead to disaster, as these three photos and the accompanying text illustrate. or iron objects. If the compass cannot be placed at least two feet (six feet would be better) from one of these influences, then either the compass or the other object must be moved, if first order accuracy is to be expected. Once the compass location appears to be satisfactory, give the compass a test before installation. Hidden influences may be concealed under the cabin top, forward of the cabin aft bulkhead, within the cockpit ceiling, or in a wood-covered stanchion. Move the compass around in the area of the proposed location. Keep an eye on the card. A magnetic influence is the only thing that will make the card turn. You can quickly find any such influence with the compass. If the influence can not be moved away or replaced by one of non-magnetic rna terial, test to determine whether it is merely magnetic, a small piece of iron or steel, or some magnetized steel. Bring the north pole of the compass near the object, then shift and bring the south pole near it. Both the north and south poles will be attracted if the compass is demagnetized. If the object attracts one pole and repels the other, then the compass is magnetized. If your compass needs to be demagnetized, take it to a shop equipped to do the job PROPERLY. After you have moved the compass around in the proposed mounting area, hold it down or tape it in position. Test everything you feel might affect the compass and cause a deviation from a true reading. Rotate the wheel from hard over to hard over. Switch on and off all the Lights, radios, radio direction finder, radio telephone, depth finder and the shipboard intercom, if one is installed. Sound the electric whistle, turn on the windshield wipers, start the engine (with water circulating through the engine), work the throttle, and move the gear shift lever. If the boat has an auxiliary genera tor, start it. If the card moves during any one of these tests, the compass should be relocated. Naturally, if something like the windshield wipers cause a slight deviation, it may be necessary for you to make a different deviation table to use only when certain pieces of equipment is operating. Bear in mind, following a course that is only off a degree or two for several hours can make considerable difference at the end, putting you on a reef, rock, or shoal. Check to be sure the intended compass site is solid. Vibration will increase pivot wear. Now, you are ready to mount the corn pass. To prevent an error on all courses, the line through the lubber line and the compass card pivot must be exactly parallel to the keel of the boat. You can establish the fore-and-aft line of the boat with a stout cord or string. Use care to transfer this line to the compass site. If necessary, shim the base of the compass until the stile-type lubber line (the one affixed to the case and not gimbaled) is vertical when the boat is on an even keel. Drill the holes and mount the compass. Magnetic Items After Installation Many times an owner will install an expensive stereo system in the cabin of his boat. It is not uncommon for the speakers to be mounted on the aft bulkhead up against the overhead (ceiling). In almost every case, this position places one of the speakers in very close proximity to the compass, mounted above the ceiling. As we all know, a magnet is used in the operation of the speaker. Therefore, it is very likely that the speaker, mounted almost under the compass in the cabin will have a very pronounced affect on the compass accuracy. Consider the following test and the accompanying photographs as prove of the statements made. First, the compass was read as l90 degrees while the boat was secure in her slip. Next a full can of diet coke in an aluminum can was placed on one side and the compass read as 204 degrees, a good 14 degrees off. Next, the full can was moved to the opposite side of the compass and again a reading was observed. This time as 189 degrees, 11 degrees off from the original reading. Finally the contents of the can were consumed, the can placed on both sides of the compass with NO affect on the compass reading. Two very important conclusions can be drawn from these tests. 1-Something must have been in the contents of the can to affect the compass so drastically. ANCHORS 1-17 2-Keep even "innocent" things clear of the compass to avoid any possible error in the boat's heading. REMEMBER, a boat moving through the 5water at 10 knots on a compass error of just degrees will be almost 1.5 miles off course in only ONE hour. At night, or in thick weather, this could very possibly put the boat on a reef, rock, or shoal, with disastrous results. 1-1 1 STEERING USCG or EIA certification of a steering system means that all materials, equipment1 and installation of the steering parts meet or exceed specific standards for strength, type, and maneuverability. Avoid sharp bends when routi.n£ the cable. Check to be sure the pulleys turn freely and aH fittings are secure. 1-12 ANCHORS One of the most important pieces of equipment in the boat next to the power plant is the ground tackle carried. The engine makes the boat go and the anchor and its line are what hold it in place when the boat is not secured to a dock or on the beach. The weight of the anchor MUST be adequate to secure the boat without dragging. 1-18 SAFETY The anchor must be of suitable size, type, and weight to give the skipper peace of mind when his boat is at anchor. Under certain conditions, a second, smaller, lighter anchor may help to keep the boat in a favorable 'position during a non-emergency daytime situation. . In order for rhe anchor to hold properly, a piece of chain must be attached to the anchor and then the nylon anchor line attached to the chain. The amount of chain should equal or exceed the length of the boat. Such a piece of chain will ensure that the anchor stock will lay in an approximate horizontal position and permit the flutes to dig into the bottom and hold. 1-13 MISCELLANEOUS EQUIPMENT In addition to the equipment you are legally required to carry in the boat and those previously mentioned, some extra items will add to your boating pleasure and safety. Practical suggestions would include: a bailing device (bucket, pump, etc.), boat The bilge pump line must be cleaned frequently to ensure the entire bilge pump system will function properly in an emergency. hook, fenders, spare propeller, spare engine parts, tools, an auxiliary means of propulsion (paddle or oars), spare can of gasoline, flashlight, and extra warm clothing. The area of your boating activity, weather conditions, length of stay aboard your boat, and the specific purpose will all contribute to the kind and amount of stores you put aboard. When it comes to personal gear, heed the advice of veteran boaters who say, "Decide on how little you think you can get by with, then cut it in half". Bilge Pumps Automatic bilge pumps should be equipped with an overriding manual switch. They should also have an indicator in the operator's position to advise the helmsman when the pump is operating. Select a pump that will stabilize its temperature within the manufacturer's specified limits when it is operated continuously. The pump motor should be a sealed or arcless type, suitable for a marine atmosphere. Place the bilge pump inlets so excess bilge water can be removed at all normal boat trims. The intakes should be properly screened to prevent the pump from sucking up debris from the bilge. Intake tubing should be of a high quality and stiff enough to resist kinking and not collapse under maximum pump suction condition if the intake becomes blocked. To test operation of the bilge pump, operate the pump switch. If the motor does not run, disconnect the leads to the motor. Connect a voltmeter to the leads and see if voltage is indica ted. If voltage is not indicated, then the problem must be in a blown fuse, defective switch, or some other area of the electrical system. If the meter indicates voltage is present at the leads, then remove, disassemble, and inspect the bilge pump. Clean it, reassemble, connect the leads, and operate the switch again. If the motor still fails to run, the pump must be replaced. To test the bilge pump switch, first disconnect the leads from the pump and connect them to a test light or ohmmeter. Next, hold the switch firmly against the mounting location in order to make a good ground. Now, tilt the opposite end of the switch upward until it is activated as indicated by the test light coming on or the ohmmeter showing continuity. Finally, lower the switch slowly toward the mounting position until it is deactivated. \1easure the distance between the point the S\Vi tc:h was ac tivated and the point it \Vas deacti hited. For proper service, the switch should deactivate between l /2-i nch and 1/'f-inch Jrom the planfled mounting posi tbn. CA UTION: The switch must never-be mounted lower than the bilge pump pickup. 1-14 BOATING ACCIDENT REPORTS New federal and state regula tlons require an accid..nt repor t to be filed with the nearest State boating authority within 48 hours if a person is lost, disa.ppears, r boats over 39' 4" (1 2 meters) siw:e 198 t, is to obtain an official copy of the ":<. •Jles of the Road", which includes Inland \Vaterways, Western R.iters, and the Great Lakes for study and reiidy reference. ThE" following two paragraphs give a VERY brief condensed and abbreviated almost a synopsis of the rules and should not be considered in any way as covering the entire subject. Po\vered boats must yield the right-ofway to all boats without motors, except when being overtaken. When mee thg another boat head-on, keep to starboard, un! ess you are too far to por t to make this practical. When overtaking another boat, the right-of-way belongs to the boat being overtaken. If your boat is being passed, you must maintain course and speed. When two boats approach at an angle and there is danger of collision, the boat to port :nust give wav to the boat to starboard. Always keep to starboard in a narrow chan:1 el or canal. Boats underway must stay clear of vessels fishing with nets, lines, or trawls. (Fishing boats are not allowed to fish in channels or to obstruct navigation.) Daymark Daymark MODIFICATIONS: Port hand aids will MODIFICATIONS: -Green will replace be green with green lights. All starboard black. Light rhythm will be changed to hand aids will have red lights. Composite Gp Fl (2 + 1). 2 TUNING 2-1 INTRODUCTION The efficiency, reliability, fuel economy and enjoyment available from engine performance are all directly dependent on having it tuned properly. The importance of performing service work in the sequence detailed in this chapter cannot be over emphasized. Before making any adjustments, check the Specifications in the Appendix. NEVER rely on memory when making critical adjustments. Before beginning to tune any engine, check to be sure the engine has satisfactory compression. An engine with worn or broken piston rings, burned pistons, or badly scored cylinder walls, cannot be made to perform properly no matter how much time and expense is spent on the tune-up. Poor compression must be corrected or the tuneup will not give the desired results. The opposite of poor compression would be to consider good compression as evidence of a satisfactory cylinder. However, this is not necessarily the case, when working on an outboard engine. As the professional mechanic has discovered, many times the compression check will indicate a satisfactory cylinder, but after the head is pulled A clean boat and engine-appearance reflects this owner's pride in his unit. Keeping the interior well Damaged piston, probably caused by inaccurate fuel lubricated and properly adjusted will give him the mixture, or improper point setting. enjoyment deserved for his investment. 2-2 TUNING and an inspection made, the cylinder will require service. A practical maintenance program that is followed throughout the year, is one of the best methods of ensuring the engine will give satisfactory performance at any time. The extent of the engine tune-up is usually dependent on the time lapse since the last service. A complete tune-up of the entire engine would entail almost all of the work outlined in this manual. A logical sequence of steps will be presented in general terms. If additional information or detailed service work is required, the chapter containing the instructions will be referenced. Each year higher compression ratios are built into modern outboard engines and the electrical systems become more complex, especially with electronic (capacitor discharge) units. Therefore, the need for reliable, authoratative, and detailed instructions becomes more critical. The information in this chapter and the referenced chapters fulfill that requirement. 2-2 TUNE-UP SEQUENCE If twenty different mechanics were asked the question, "What constitutes a major and minor tune-up?", it is entirely possible twenty different answers would be given. As the terms are used in this manual and other Seloc outboard books, the following work is normally performed for a minor and major tune-up. Mi nor Tune-up Lubricate engine. Drain and replace gear oil. Ad just points. Adjust carburetor. Clean exterior surface of engine. Tank test engine for fine adjustments. Major Tune-up Remove head. Clean carbon from pistons and cylinders. Clean and overhaul carburetor. Clean and overhaul fuel pump. Rebuild and adjust ignition system. Lubricate engine. Drain and replace gear oil. Clean exterior surface of engine. Tank test engine for fine adjustments. During a major tune-up, a definite sequence of service work should be followed to return the engine to the maximum performance desired. This type of work should not be confused with attempting to locate problem areas of "why" the engine is not performing satisfactorily. This work is classified as "troubleshooting". In many cases, these two areas will over lap, because many times a minor or major tune-up will correct the malfunction and return the system to normal operation. The time, effort, and expense of a tune-up will not A boat and lower unit covered with marine growth. restore an engine to satisfactory performance, if the Such a condition is a serious hinderance to satisfactory pistons are damaged. performance. The following list is a suggested sequence of tasks to perform during the tuneup service work. The tasks are merely listed here. Generally procedures are given in subsequent sections of this chapter. For more detailed instructions.. see the referenced chapter. 1-Perform a compression check of each cylinder, see next section. 2-Inspect the spark plugs to determine their condition. Test for adequate spark at the plug, see Section 2-4. 3-Start the engine in a body of water and check the water flow through the engine. See Chapter 8. 4-Check the gear oil in the lower unit. See Chapter 8. 5-Check the carburetor adjustments and the need for an overhaul. See Chapter 4. COMPRESSION CHECK 2-3 2-3 COMPRESSION CHECK A compression check is extremely important, because an engine with low or uneven compression between cylinders CANNOT be tuned to operate satisfactorily. Therefore, it is essential that any compression problem be corrected before proceeding with the tune-up procedure. See Chapter 3. If the powerhead shows any indication of overheating, such as discolored or scorched paint, especially in the area of the top (No. 1) cylinder, inspect the cylinders visually thru the transfer ports for possible scoring. A more thorough inspection can be made if the head is removed. It is possible for a cylinder with satisfactory compression to be scored slightly. Also, check the water pump. The overheating condition may be perform ance and 7tion system . See Chapter 5. 8 caused by a faulty water pump. Check the fuel pump for adequate An overheating condition may also be delivery. See Chapter caused by running the engine out of the water. For unknown reasons, many opera Make a general inspection of the igni tors have formed a bad habit of running a small engine without the lower unit being submerged. Such a practice will result in an Test the starter motor and the sole noid. See Chapter 7. overheated condition in a matter of seconds. 9-Check the internal wiring. 10-Check the timing and synchronization. See Chapter 5. It is interesting to note, the same operator would never operate or allow anyone else to run a large horsepower engine without water circulating through the lower unit for cooling. Bear-in-mind, the laws governing operation and damage to a large unit ALL apply equally as well to the small engine. A compression check should_ be taken in each cylinRemoving the spark plugs for inspection. Worn der before spending time and money on tune-up work. plugs are one of the major contributing factors to poor Without adequate compression, efforts in other areas to engine performance. regain engine performance will be wasted. 2-4 TuNING Damaged spark plugs. Notice the broken electrode on the left plug. The broken part must be found and re moved before returning the engine to service. Checking Compression Remove the spark plug wires. ALWAYS grasp the molded cap and pull it loose with a twisting motion to prevent damage to the connection. Remove the spark plugs and keep them in ORDER by cylinder for evaluation later. Ground the spark plug leads to the engine to render the ignition system inoperative while performing the compression check. Insert a compression gauge into the No. 1, top, spark plug opening. Crank the engine with the starter, or pull on the starter.. cord, thru at least 4 complete strokes with the throttle at the wide-open position, or until the highest possible reading is observed on the gauge. Record the reading. Repeat the test and record the compression for each cylinder. A variation between cylinders is far more important than the actual readings. A variation of more than 5 psi between cylinders indicates the lower compression cylinder may be defective. The problem may be worn, broken, or sticking piston rings, scored pistons or worn cylinders. These problems may only be determined after the head has been removed. Removing the head on an outboard engine is not that big a deal and may save many hours of frustration and the cost of purchasing unnecessary parts to correct a faulty condition. 2-4 SPARK PLUG INSPECTION Inspect each spark plug for badly worn electrodes, glazed, broken, blistered, or lead fouled insulators. Replace all of the plugs, if one shows signs of excessive wear. Make an evaluation of the cylinder performance by comparing the spark condition with those shown in Chapter 5. Check each spark plug to be sure they are all of the same manufacturer and have the same heat range rating. Inspect the threads in the spark plug opening of the head and clean the threads before installing the plug. If the threads are damaged, the head should be removed and and a Heli-coil insert installed. If an attempt is made to drill out the opening with the head in place, some of the filings may fall into the cylinder and cause damage to the cylinder wall during operation. Because the head is made of aluminum, the filings cannot be removed with a magnet. When purchasing new spark plugs, ALWAYS ask the marine dealer if there has been a spark plug change for the engine being serviced. Crank the engine through several revolutions to blow out any material which might have become dislodged during cleaning. Install the spark plugs and tighten them to the proper torque value. ALWAYS use a new gasket and wipe the seats in the block clean. The gasket must be fully compressed Today, numerous type spa..k plugs are available for A fouled spark plug. The condition of this plug service. ALWAYS check with your local marine dealer indicates problems in the air/fuel mixture or the to be sure you are purchasing the proper plugs for the amount of oil added to the mixture. engine being serviced. SYNCHRONIZING 2-5 Worn ignition points are a common problem area contributing to poor engine performance. on clean seats to complete the heat transfer process and to provide a gas tight seal in the cylinder. If the torque value is too high, the heat will dissipate too rapidly. Conversely, if the torque value is too low, heat will not dissipate fast enough. 2-5 IGNITION SYSTEM Four different ignition systems are usee on outboard engines covered in this manual: A flywheel magneto; a low-tension magneto; a capacitor discharge (CD) system with timer base; and a CD with a sensor coil. If engine performance is less than expected, and the ignition is di<:Jgnosed as the problem area, refer to Chatper 5 for detailed service procedures. To properly synchronize the ignition system with the fuel system, see appropriate Section in Chapter 5. The fuel and ignition systems on any engine MUsr be properly synchronized before maximum performance can be obtained from the unit. Breaker Poi nts Engines equipped with either the fly wheel magneto or low-tension magneto sys te ms utilize breaker points. Breaker points are NOT used in the magneto capacitor discharge (CD) ignition system. Rough or discolored contact surfaces are sufficient reason for replacement. The cam follower will usually have worn away by the time the points have become unsatisfactory for efficient service. Check the resistance across the con tacts. If the test indicates ZERO resis tance, the points are serviceable. A slight resistance across the points will affect idle operation. A high resistance may cause the ignition system to malfunction and loss of spark. Therefore, if any resistance across the points is indicated, the point set should be replaced. 2-6 SYNCHRONIZING The timing on small OMC (Johnson and Evinrude) outboard engines is controlled through adjustment of the points. On the 40hp, 50hp, 55hp, and 60hp engines, and some newer smaller models, the timing is adjustable through the synchronization, see Chapter 5. If the points are adjusted too closely, the spark plugs will fire early; if adjusted with excessive gap, the pbgs will fire too late, for efficient operation. Therefore, correct point adjustment and synchronization are essential for proper engine operation. An engine may be in appareht excellent mechanical condition, but perform poorly, unless the points anc synchronization have been adjusted precisely, according to the Specifications in the Appendix. To synchronize the engine, see Chapter 5. The battery MUsr be locqted near the engine in a well-ventilated area. It must be secured in such a manner that absolutely no movement is possible in any direction under the most violent action of the boat. 2-6 TUNING 2-7 BATTERY SERVICE Many owner/operators are not fully aware of the role a battery performs with a magneto ignition system outboard engine. To clarify:· With a magneto ignition system, a battery is only used to crank the engine for starting purposes. Once the engine is running properly, the battery could very well be removed without affecting engine operation. Therefore, if the battery is completely dead, the engine may be hand started with a pull cord and operate efficiently. If a battery is used for starting, inspect and service the battery, cables and connections. Check for signs of corrosion. Inspect the battery case for cracks or bulges, dirt, acid, and electrolyte leakage. Check the electrolyte level in each cell. Fill each cell to the proper level with distilled water or water passed thru a demineralizer. Clean the top of the battery. The top of a 12-·volt battery should be kept especially clean of acid film and dirt, because of the high voltage between the battery terminals. For best results, first wash the battery with a diluted ammonia or baking soda solution to An inexpensive brush should be purchased and used to clean the battery terminals. Clean terminals will ensure a proper connection. neutralize any acid present. Flush the solution off the battery with clean water. Keep the vent plugs tight to prevent the neutralizing solution or water from entering the cells. Check to be sure the battery is fastened securely in position. The hold-down device should be tight enough to prevent any movement of the battery in the holder, but not so tight as to place a strain on the battery case. Common set of jumper ca_bles for using a second battery to crank and start the engine. EXTREME care A check of the electrolyte in the battery should be a should be used when using a second battery, as explain regular task on the maintenance schedule on any boat. ed in the text. If the battery posts or cable terminals are corroded, the cables should be cleaned separately with a baking soda solution and a wire brush. Apply a thin coating of Multipurpose Lubricant to the posts and cable clamps before making the connections. The ' lubricant will help to prevent corrosion. If the battery has remained under-charged, check for high resistance in the charging circuit. If the battery appears to be using too much water, the battery may be defective, or it may be too small for the job. Jumper Cables If booster batteries are used for starting an engine the jumper cables must be connected correctly and in the proper sequence to prevent damage to either battery, or the alternator diodes. ALWAYS connect a cable from the positive terminals of the dead bz:.ttery to the positive terminal of the goocl b...ttery FIRST. NEXT, connect one end of the other ca.ble to the negative terminals of the good battery and the ot her emi on the ENGINE for a gooc! ground. By makin... the ground connection on the enpine? if there is an arc when you make the connection it wiH not be near the ba,ttery. An arc near the bcttery could cause an explosion, clestroyin!l' the batter y and causing serious personal injury. DISCONNECT the battery ground cable before replacing an alternator or before connecting any type of meter to. the alternator. If it is necessary to use a fast-charger on a dead battery, ALWAYS disconnect one of A 40 hp engine with a starter installed on the starboard side and a generator on the port side. The generator, in kit form, is available from the local OMC dealer. BATTERY SERVICE 2-7 the boat cables from the battery first, to prevent burning out the diodes in the alter nator. NEVER use a fast charger as a booster to start the engine because the diodes in the altern a tor will be DAMAGED. Generator Charging Normally a generating system is not standard equipment on the smaller horse power engines, up to the 40 hp model. However, a generator kit may be purchased and installed on the 40 hp engines for bat tery cha.rF!ing while the engine is operating. A generator system is standard equipment of the 40 hp electric shift model. When the battery is partially discharged, the ammeter should change from discharge to charge between 1500 to 1800 rpm for all models. If the battery is fully-charged, the rpm will be a little higher. With the engine running, in gear, in the water, increase the throttle until the rpm is approximately 5200 rpm. The ammeter reading should meet the Alternator Specifi cations in the Appendix. With a fully charged battery the ammeter reading will be a bit lower because of the self-regulating characteristics of the generating systems. Before disconnecting the ammeter, remove the red harness lead connected to the posi tive battery terminal. Alternator Charging When the battery is partially discharged, the ammeter should change from discharge to charge between 800 to lOOOrpm for all models. If the battery is fully-charged, the rpm will be a little higher. View of the armature plate with the flywheel removed to show the generating coils mounted on the plate. 2-8 TUNING With the engine running, increase the throttle to approximately 5200 rpm. The ammeter reading should be approximately equal to the amperage rating of the al ternator installed. With a fully-charged battery, the ammeter reading will be a bit lower because of the self-regulating characteristics of the generating systems. Before disconnecting the ammeter, reconnect the red harness lead to the positive battery terminal and install the wing nut. 2-8 CARBURETOR ADJUSTMENTS Fuel and Fuel Tanks Take time to check the fuel tank and all of the fuel lines, fittings, couplings, valves, flexible tank fill and vent. Turn on the fuel supply valve at the tank, if the engine is equipped with a self-contained fuel tank. If the gas was not drained at the end of the previous season, make a careful inspection for gum formation. When gasoline is al lowed to stand for long periods of time, particularly in the presence of copper, gum my deposits form. This gum can clog the filters, lines, and passageway in the carbu retor. If the condition of the fuel is in doubt, drain, clean, and fill the tank with fresh fuel. Fuel pressure at the carburetor should be checked whenever a lack of fuel volume at the carburetor is suspected. High-speed Adjustment The high-speed neecle valve is adjustable on some models covered in this manual through 1974. After 19759 the high-speed orifice is fixed at the factory and is NOT adjustable. However, larger or smaller orifices !T'ay be installed for different elevations. On all Johnson/Evinrude engines, the high-speed needle valve, or orifice9 is the lower valve on the carburetor. The upper needle valve is always the idle adjustment. A beginning "rough" adjustment for the high-speed needle valve is 3/4 turn out (counterclockwise) from the lightly seated (closed) position. TAKE CARE not to seat the valve firmly to prevent damage to the valve or the carburetor. To make the high-speed adjustment: a-Mount the engine in a test tank or body of water, preferably with a test wheel. Engines up to 40 hp may be operated in the high rpm range in a test tank without sustaining damage. NEVER, AGAIN NEVER, operate the engine at high speed with a flush device attached. The engine, operating at high speed with such a device attached, would RUN-AWAY from lack of a load on the propeller, causing extensive damage. b-Connect a tachometer to the engine. CAUTION: Water must circulate through the lower unit to the engine any time the engine is run to prevent damage to the water pump in the lower unit. Just five seconds without water will damage the water pump. c-Start the engine and allow it to warm to operating temperature. d-Shift the engine into forward gear. e-With the engine running in forward ' IDlE ADJUSTMENT An OMC six-gallon fuel tank with the fuel line connected through a quick-disconnect fitting. Such a fitting is handy when the tank is removed from the boat Small horsepower engine mounted in a test tank for filling. with the low-and high-speed adjustments indicated. gear, advance the throttle to the wide open position, and then very SLOWLY turn the high-speed needle valve inward (CLOCKWISE) until the engine begins to loose rpm. Now, SLOWLY rotate the needle valve outward (COUNTERCLOCKWISE) until the engine peaks out at the highest rpm. If the high-speed needle valve adjustment is too lean, the low-speed adjustment will be affected. Under certain conditions it may be necessary to adjust the high-speed needle valve just a bit richer in order to obtain a satisfactory idle adjustment. After the high-speed needle adjustment has been obtained, proceed with the idle adjustment as outlined in the next paragraphs. Idle Adjustment Due to local conditions, it may be necessary to adjust the carburetor while the engine is running in a test tank or with the boat in a body of water. For maximum performance, the idle mixture and the idle rpm should be adjusted under actual operating conditions. Set the idle mixture screw at the specified number of turns open from a lightly seated position. In most cases this is from 1 to 1 Y2 turns open from close. Start the engine and allow it to warm to operating temperature. CAUTION: Water must circulate through the lower unit to the engine any time the engine is run to prevent damage to the water pump in the lower unit. Just five seconds without water will damage the water pump. A 40hp powerhead with the idle adjustment screw and the high speed orifice plug identified. FUEL PUMP 2-9 NEVER, AGAIN NEVER, operate the engine at high speed with a flush device attached. The engine, operating at high speed with such a device attached, would RUN-AWAY from lack of a load on the propeller, causing extensive damage. With the engine running in forward gear, slowly turn the idle mixture screw COUNTERCLOCKWISE until the affected cylinders start to load up or fire unevenly, due to an over-rich mixture. Slowly turn the idle mixture screw CLOCKWISE until the cylinders fire evenly and engine rpm increases. Continue to slowly turn the screw CLOCKWISE until too lean a mixture is obtained and the rpms fall off and the engine begins to misfire. Now, set the idle mixture screw one-quarter (1/4) turn out (counterclockwise) from the lean-out position. This adjustment will result in an approximate true setting. A too-lean setting is a major cause of hard starting a cold engine. It is better to have the adjustment on the rich side rather than on the lean side. Stating it another way, do not make the adjustment any leaner than necessary to obtain a smooth idle. If the engine hesitates during acceleration after adjusting the idle mixture, the mixture is too lean. Enrich the mixture slightly, by turning the adjustment screw inward until the engine accelerates correctly. With the engine running in forward gear, rotate the nylon idle adjustment screw, located on the portside of the engine, until the engine idles at the recommended rpm, as given in the Specifications in the Appendix. This idle adjustment screw is always exposed on the outside of the shroud. Repairs and Adjustments For detailed procedures to disassemble, clean, assemble, and adjust the carburetor, see the appropriate section in Chapter 4 for the carburetor type on the engine being serviced. 2-9 FUEL PUMPS Many times , a defective fuel pump diaphragm is mistakenly diaf':nosed as a problem in the i..niti.on system. The most comm on problem is a tiny pin-hole in the diaphragm . Such a small -hole V'iH permit ,gas to enter the crankcase anc' wet foul the spark olug at idle-speed. Curing high-speed 2-10 TUNING Two of the many types of fuel pumps installed on OMC outboard engines. These fuel pumps cannot be rebuilt, as explained in the text. operation, gas quantity is limited, the plug is not foul and will therefore fire in a satisfactory manner. If the fuel pump fails to perform properly, an insufficient fuel supply will be delivered to the carburetor. This lack of fuel will cause the engine to run lean, lose rpm or cause piston scoring. When a fuel pressure gauge is added to the system, it should be installed at the end of the fuel line leading to the upper carburetor. To ensure maximum performance, the fuel pressure must be 2 psi or more at full throttle. Tune-up Task Most fuel pumps are equipped with a fuel filter. The filter may be cleaned by first removing the cap, then the filter element, cleaning the parts and drying them with compressed air, and finally installing them in their original position. A fuel pump pressure test should be made any time the engine fails to perform satisfactorily at high speed. NEVER use liquid Neoprene on fuel line fittings. Always use Permatex when making fuel line connections. Permatex is available at almost all marine and hardware stores. Only one Johnson/Evinrude fuel pump may be rebuilt, see accompanying illustration. All others pumps must be replace as a unit. For fuel pump service, see Chapter 4. 2-10 STARTER AND SOLENOID Starter Motor Test Check to be sure the battery has a 70ampere rating and is fully charged. Would you believe, many starter motors are needlessly disassembled, when the battery is actually the culprit. Lubricate the pinion gear and screw shaft with No. 10 oil. Commercial additives, such as Sta-bil, may be used to keep the gasoline in the fuel tank fresh. Under Starter Bendix drive mechanism. Good maintenance favorable conditions, such additives will prevent the practices should include just a drop of 10-weight oil fuel from "souring" for up to twelve months. periodically to the area shown. INTERNAL WIRING 2-11 have been discarded because of the erroneous belief the case is providing a ground and the unit should function when 12-volts is applied. Not so! One terminal of the solenoid is connected to a 12-volt source. The other terminal is connected via a white wire to a cutout switch on top of the engine. This cutout switch provides a safety to break the ground to the solenoid in the event the engine starts at a high rpm. Therefore, the solenoid ground is made and broken by the cutout switch. NEVER connect the battery leads to the large terminals of the solenoid, or the test meter will be damaged. Connect each lead of the test meter to each of the large terminals on the solenoid. Using battery jumper leads, connect the positive lead from the positive terminal of the battery to the the small "S" terminal of the solenoid. Connect the negative lead to the the "I" terminal of the solenoid. Connect the other end of the jumper lead to the negative battery terminal. If the meter indicates continuity, the solenoid is serviceable. If the meter fails to indicate continuity, the solenoid must be replaced. 2-11 INTERNAL WIRING HARNESS An internal wiring harness is only used on the larger horsepower engines covered in this manual. If the engine is equipped with a wiring harness, the following checks and test will apply. Check the internal wiring harness if problems have been encountered with any of the electrical components. Check for frayed or chafed insulation and/ or loose connections between wires and terminal connections. Check the harness connector for signs of corrosion. If the harness shows any evidence of damage or corrosion, the problem must be corrected before proceeding with any harness testing. Convince yourself a good electrical connection is being made between the harness connector and the remote control harness. 2-12 WATER PUMP CHECK FIRST A GOOD WORD: The water pump MUST be in very good condition for the engine to deliver satisfactory service. The pump performs an extremely important function by supplying enough water to properly cool the engine. Therefore, in most Functional diagram of a typical cranking circuit. Connect one lead of a voltmeter to the positive terminal of the starter motor. Connect the other meter lead to a good ground on the engine. Check the battery voltage under load by turning the ignition switch to the START position and observing the voltmeter reading. If the reading is 9-1/2 volts or greater, and the starter motor fails to operate, repair or replace the starter motor. See Chapter 7. Solenoid Test An ohmmeter is the only instrument required to effectively test a solenoid. Test the ohmmeter by connecting the red and black leads together. Adjust the pointer to the right side of the scale. On all Johnson/Evinrude engines the case of the solenoid does NOT provide a suitable ground to the engine. Hundreds of solenoids OHMMETER TEST LEADS Proper hook-up of an ohmmeter in preparation to testing a starter solenoid. 2-12 TUNING FLUSH ATTACHMENT Using a flush attachment with a garden hose hookup to clean the engine water circulation system with fresh water. This arrangement may also be used while operating the engine at idle speeds to make adjustments. cases, it is advisable to replace the com plete water pump assembly at least once a year, or anytime the lower unit is disassem bled for service. Sometimes during adjustment procedures, it is necessary to run the engine with a flush device attached to the lower unit. NEVER operate the engine over 1000 rpm with a flush device attached, because the engine may "RUNAWAY" due to the no-load condition on the propeller. A "runaway" engine could be severely damaged. As the name implies, the flush device is primarily used to flush the engine after use in salt water or contaminated fresh wa ter. Regular use of the flush device will prevent salt or silt deposits from accumulating in the water passageway. During and immedi ately after flushing, keep the motor in an upright position until all of the water has drained from the drive shaft housing. This will prevent water from entering the power head by way of the drive shaft housing and the exhaust ports, during the flush. It will TUBE GU IDE Water pump installed on a 50 hp lower unit. also prevent residual water from being trapped in the drive shaft housing and other passageways. To test the water pump, the lower unit MUST be placed in a test tank or the boat moved into a body of water. The pump must now work to supply a volume to the engine. Lack of adequate water supply from the water pump thru the engine will cause any number of powerhead failures, such as stuck rings, scored cylinder walls, burned pistons, etc. 2-13 PROPELLER Check the propeller blades for nicks, cracks, or bent condition. If the propeller is damaged, the local marine dealer can make repairs or send it out to a shop specializing in such work. Remove the cotter key, propeller nut, shear pin, and the propeller from the shaft. Check the propeller shaft seal to be sure it is not leaking. Check the area just forward of the seal to be sure a fish line is not wrapped around the shaft. When installing the propeller, ALWAYS use an OMC or approved seal compound on the propeller shaft splines to prevent the propeller from seizing onto the shaft. Example of a damaged propeller. This unit should have been replaced long before this amount of damage was sustained. LOWER UNIT 2-13 Considerable amount of fish line entangled around the propeller shaft. Some of the fish line actually melted, giving it the appearance of a washer. Operation At Recommended RPM Check with the local OMC dealer, or a propeller shop for the recommended size and pitch for a particular size engine, boat, and intended operation. The correct propeller should be installed on the engine to enable operation at recommended rpm. Two rpm ranges are usually given. The lower rpm is recommended for large, heavy slow boats, or for commercial applications. The higher rpm is recommended for light, fast boats. The wide rpm range will result in greater satisfaction because of maximum performance and greater fuel economy. If the engine speed is above the recommended rpm, try a higher pitch propeller or the same pitch cupped. See Chapter 1 for explanation of propeller terms, pitch, diameter, cupped, etc. For a dual engine installation, the next higher pitch propeller may prove the most satisfactory condition for water skiing. 2-14 LOWER UNIT NEVER remove the vent or filler plugs when the lower unit is hot. Expanded lubricant would be released through the plug New propeller ready for installation. Rebuilding a small propeller is not economical when balanced against the minor difference of purchasing a new unit. hole. Check the lubricant level after the unit has been allowed to cool. Add only OMC approved gear lubricant. NEVER use regular automotive-type grease in the lower unit, because it expands and foams too much. Outboard lower units do not have provisions to accommodate such expansion. If the lubricant appears milky brown, indicating the presence of water, a check should be made to determine how the water entered. If large amounts of lubricant must be added to bring the lubricant up to the full mark, a thorough inspection should be made to find the cause of the lubricant loss. Draining Lower Unit The fill/drain plug on Johnson/Evinrude lower units may be located towards the bottom of the unit on the port side, starboard side, or on the leading edge of the The gear oil in the lower unit should be checked on a Considerable debris entangled behind the propeller. daily basis during the season of operation. The oil This type of maintenance neglect will seriously affect should be drained and replenished "»ith new oil every powerhead efficiency and boat performance. 100 hours of operation. 2-14 TUNING lower unit. On many models a Phillips screw will be found very close to the fill/ drain plug. NEVER remove this Phillips screw because the lower unit would then have to be disassembled in order to return the cradle 'for the shift dog back in place. Remove the drain plug and then remove the vent plug located just above the anticavitation plate. Filling Lower Unit Position the drive unit approximately vertical and without a list to either port or starboard. Insert the lubricant tube into the FILL/DRAIN hole at the bottom plug hole, and inject lubricant until the excess begins to come out the VENT hole. Install the VENT plug first then replace the FILL plug with NEW gaskets. Check to be sure the gaskets are properly positioned to prevent water from entering the housing. Many times some of the gear lubricant is lost during installation of the plugs. Therefore, if the vent plug is removecl again, and more lubricant added very SLOWLY using a smallspout oil can to allow air to pass ou t the opening, the unit will be filled to capacity. For detailed lower unit service procedures .. see Chapter 8. For lower uni t lubrication capacities, see the Appendix. Filling the lower Wlit with new gear oil. Notice the unit is filled through the lower drain plug. The vent plug MUST be removed to allow trapped air to escape. HOOK ROCKER Boat performance will be drastically hampered, if the bottom is damaged. Repairs and Adjustments For detailed procedures to disassemble, clean, assemble, and adjust the carburetor, see the appropriate section in Chapter 4 for the carburetor type on the engine being serviced. 2-15 BOAT TESTING Hook and Rocker Before testing the boat, check the boat bottom carefully for marine growth or evidence of a "hook" or a "rocker" in the bottom. Either one of these conditions will greatly reduce performance. Performance Mount the motor on the boat. Install the remote control cables and check for proper adjustment. Make an effort to test the boat with what might be considered an average gross load. The boat should ride on an even keel, without a list to port or starboard. Adjust the motor tilt angle, if necessary, to permit the boat to ride slightly higher than the stern. If heavy supplies are stowed aft of the center, the bow will be light and the boat will "plane" more efficiently. For this test the boat must be operated in a body of water. Check the engine rpm at full throttle. The rpm should be within the Specifications in the Appendix. All OMC engine model serial number identification plates indicate the horsepower rating and rpm range for the engine. If the rpm is not within specified range, a propeller change may be in order. A higher pitch propeller will decrease rpm, and a lower pitch propeller will increase rpm. For maximum low speed engine performance, the idle mixture -and the idle rpm should be readjusted under actual operating conditions. 3 POWER HEAD 3-1 INTRODUCTION The carburetiori and ignition princip1es of two-cycle engine operation MUST be understood in order to perform a proper tuneup on an outboard motor. Therefor_, it would be well worth the time, .,.... ..:dy the principles of two-cycle engines, as outlined in this section. A Polaroid, or equivalent instant-type cam era is an extremely useful item providing the means of accurately recording the arrangement of parts and wire connections BEFORE the disassembly work begins. Such a record is most valuable during the assembly work. Tags are handy to identify wires after they are disconnected to ensure they will be connected to the same terminal from which they were removed. These tags may also be used for parts where marks or other means of identification is not possible. THEORY OF OPERATION The two-cycle engine differs in several ways from a conventional four-cycle (automobile) engine. 1-The method by which the fuel-air mixture is delivered to the combustion chamber. 2-The complete lubrication system. 3-In most cases, the ignition system. 4-The frequency of the power stroke. These differences will be discussed briefly and compared with four-cycle engine operation. Intake/Exhaust Two-cycle engines utilize an arrangement of port openings to admit fuel to the combustion chamber and to purge the exhaust gases after burning has been completed. The ports are located in a precise pattern in order for them to be open and closed off at an exact moment by the piston as it moves up and down in the cylinder. The exhaust port is located slightly higher than the fuel intake port. This arrangement opens the exhaust port first as the piston starts downward and therefore, the exhaust phase begins a fraction of a second before the intake phase. Actually, the intake and exhaust ports are spaced so closely together that both open almost simultaneously. For this reason, the pistons of most two-cycle engines have a deflector-type top. This design of the piston top serves two purposes very effectively. EXHAUST DEFLECTOR PORT INTAKE PORT INTAKE EXHAUST Drawing to depict the intake and exhaust cycles of a two-cycle engine. 3-2 POWERHEAD First, it creates turbulence when the incoming charge of fuel enters the combustion chamber. This turbulence results in more complete burning of the fuel than if the piston top were flat. The second effect of the deflector-type piston crown is to force the exhaust gases from the cylinder more rapidly. This system of intake and exhaust is in marked contrast to individual valve arrangement employed on four-cycle engines. Lubrication A two-cycle engine is lubricated by mixing oil with the fuel. Therefore, various parts are lubricated as the fuel mixture passes through the crankcase and the cylinder. Four-cycle engines have a crankcase containing oil. This oil is pumped through a circulating system and returned to the crankcase to begin the routing again. Power Stroke The combustion cycle of a two-cycle engine has four distinct phases. 1-Intake 2-Compression 3-Power 4-Exhaust Three phases of the cycle are accomplished with each stroke of the piston, and the fourth phase, the power stroke occurs INDUCED LOW AIR VENTURI PRESSURE ...._ with each revolution of the crankshaft. Compare this system with a four-cycle engine. A stroke of the piston is required to accomplish each phase of the cycle and the power stroke occurs on every other revolution of the crankshaft. Stated another way, two revolutions of the four-cycle engine crankshaft are required to complete one full cycle, the four phases. Physical Laws The two-cycle engine is able to function because of two very simple physical laws. One: Gases will flow from an area of high pressure to an area of lower pressure. A tire blowout is an example of this principle. The high-pressure air escapes rapidly if the tube is punctured. Two: If a gas is compressed into a smaller area, the pressure increases, and if a gas expands into a larger area, the pressure is decreased. If these two laws are kept in mind, the operation of the two-cycle engine will be easier understood. Actual Operation Beginning with the piston approaching top dead center on the compression stroke: ATMOSPHERIC AIR PRESSURE Air flow principle for a modern carburetor. Adding OMC approved oil into the fuel tank. DEFlECTOR CRANKCASE CONNECT ING ROD DEFlECTOR CRANKCASE CONNECT ING ROD THEORY OF OPERATION 3-3 The intake and exhaust ports are closed by the piston; the reed valve is open; the spark plug fires; the compressed fuel-air mixture is ignited; and the power stroke begins. The reed valve was open because as the piston moved 'upward, the crankcase volume increased, which reduced the crankcase pressure to less than the outside atmosphere. As the piston moves downward on the power stroke, the combustion chamber is filled with burning gases. As the exhaust port is uncovered, the gases, which are under great pressure, escape rapidly through the exhaust ports. The piston continues its downward movement. Pressure within the crankcase increases, closing the reed valves against their seats. The crankcase then becomes a sealed chamber. The air-fuel mixture is compressed ready for delivery to the combustion chamber. As the piston continues to move downward, the intake port is uncovered. Fresh fuel rushes through the intake port into the combustion chamber striking the top of the piston where it is deflected along the cylinder wall. The reed valve remains closed until the piston moves upward again. When the piston begins to move upward on the compression stroke, the reed valve opens because the crankcase volume has been increased, reducing crankcase pressure to less than the outside atmosphere. The INTAKE COMPRESSION Drawing to depict fuel flow of the "loop charge" while the piston is on the down stroke. intake and exhaust ports are closed and the fresh fuel charge is compressed inside the combustion chamber. Pressure in the crankcase decreases as the piston moves upward tind a fresh charge of air flows through the carburetor picking IGNITION POWER STROKE EXHAUST Complete piston cycle of a two-cycle engine, depicting intake, power, and exhaust. 3-4 POWERHEAD up fuel. As the piston approaches top dead center, the spark plug ignites the air-fuel mixture, the power stroke begins and one complete cycle has been completed. Cross Fuel Flow Principle OMC pistons area defector dome type. The design is necessary to deflect the fuel charge up and around the combustion chamber. The fresh fuel mixture enters the combusion chamber through the intake ports and flows across the top of the piston. The piston design contributes to clearing the combustion chamber, because the incoming fuel pushes the burned gases out the exhaust ports. Loop Scavenging The 40 hp (since 1983), and the 50 hp, 55 hp, and 60 hp powerheads have what is commonly known as a loop scavenging system. The piston dome is relatively flat on top with just a small amount of crown. Pressurized fuel in the crankcase is forced up through the skirt of the piston and out through irregular shaped openings cut in the skirt. After the fuel is forced out the piston skirt openings it is transfered upward through long deep grooves molded into the cylinder wall. The fuel then enters the combustion portion of the cylinder and is compressed, as the piston moves upward. Drawing to depict the exhaust leaving the cylinder and fuel entering through the three ports in the piston. This particular powerhead does not have intake cover pia tes, because the intake passage is molded into the cylinder wall as described in the previous paragraph. Therefore, if these engines are being serviced, disregard the sections covering intake cover plates. Timing The exact time of spark plug firing de pends on engine speed. At low speed the spark is retarded --fires later than when the piston is at or beyond top dead center. Therefore, the timing is advanced as the magneto armature plate advances. At high speed, the spark is advanced - fires earlier than when the piston is at top dead center. The 40 hp (since 1983), 50 hp, 55 hp, and 60 hp powerheads have a timing adjustment for low and high speeds. Procedures for making the timing adjustment will be found in Chapter 5. Summary More than one phase of the cycle occurs simultaneously during operation of a twocycle engine. On the downward stroke, power occurs above the piston while the ports are closed. When the ports open, exhaust begins and intake follows. Below the piston, fresh air-fuel mixture is compressed in the crankcase. On the upward stroke, exhaust and intake continue as long as the ports are open. Compression begins when the ports are closed and continues until the spark plug ignites the air-fuel mixture. Below the piston, a fresh air-fuel mixture is drawn into the crankcase ready to be compressed during the next cycle. 3-2 CHAPTER ORGANIZATION This chapter is divided into 14 main service sections. Each section covers a particular area of service and outlines com plete instructions for the work to be per formed. Because of the many countless number of outboard units in the field, it would be impractical and almost impossible to give detailed procedures for removal and installation of each bolt, carburetor, start er, and other "buildup" type units. Therefore, the sections, for the particu lar powerhead work to be performed, begin with the preliminary access tasks complet ed. As an example, disassembly of the DISASSEMBLING 3-5 powerhead begins with the necessary hood, cow ling, and accessories removed. The information is presented in a logical sequence for complete powerhead overhaul. The instructions can be followed generally for almost any size horsepower engine. In rare cases, where the procedures differ de pending on the model being serviced, separ ate steps are included. One example is the three different type of crankshaft installa tions. The illustrations accompanying the text are from different size units and the cap tions clearly identify which model is cover ed. Exploded drawings, showing principle parts, for the various size powerheads are included at the end of the chapter. Special tools may be called out in cer tain instances. These tools may be purchas ed from the local Johnson/Evinrude dealer or directly from Customer Services Depart ment, Outboard Marine Corporation (OMC), Waukegan, 111inois, 60085. The chapter ends with Break-in Procedures, Section 3-15, to be performed after the powerhead has been assembled, all accessories installed, and the powerhead mounted on the exhaust housing. Torque Values All torque values must be met when they are specified. Many of the outboard castings and other parts are made of aluminum. The torque values are given to prevent stretching the bolts, but more importantly to protect the threads in the aluminum. It is extremely important to tighten the connecting rods to the proper torque value to ensure proper service. The head bolts are probably the next most important torque value. Powerhead Components Service procedures for the carburetors, fuel pumps, starter, and other power head components are given in their respective chapters of this manual. See the Table of Contents. Reed Installation All reeds on Johnson/Evinrude engines covered in this manual are installed just behind the carburetor behind the intake manifold. Cleanliness Make a determined effort to keep parts and the work area as clean as possible. Parts MUST be cleaned and thoroughly inspected before they are assembled, installed, or adjusted. Use proper lubricants, or their equivalent, whenever they are recommended. Keep rods and rod caps together as a set to ensure they will be installed as a pair and in the proper sequence. Needle bearings MUST remain as a complete set. NEVER mix needles from one set with another. If only one needle is damaged, the complete set MUST be replaced. 3-3 POWERHEAD DISASSEMBLING Preliminary Work Before the powerhead can be disassembled, the battery must be disconnected; fuel lines disconnected; and the carburetor, genera tor, starter, flywheel, and magneto, aU removed. If in doubt as to how these items are to be removed, refer to the appropriate chapter. After the accessories have been removed, remove the bolts in the front and rear of the powerhead securing the powerhead to the exhaust housing. Lift the powerhead free. BAD NEWS If the unit is several years old, or if it has been operated in salt water, or has not had proper maintenance, or shelter, or any number of other factors, then separating the Cleaning the pistons while they remain in the powerhead. The pistons should be carefully inspected for burned areas and the cylinder walls for scoring. 3-6 POWERHEAD powerhead from the exhaust housing may not be a simple task. An air hammer may be required on the studs to shake the corrosion loose; heat may have to be applied to the casting to expand it slightly; or other devices employed in order to remove the powerhead. One very serious condition would be the driveshaft "frozen11 with the crankshaft. !n this case, a. circular plugtype hole must be drilled and a torch used to cut the driveshaft. Let's assume the powerhead wiH come free on the first attempt. The following procedures pickup the work after these preliminary tasks have been completed!. 3-4 HEAD SERVICE Usually the head is removed and an examination of the cylinders made to determine the extent of overhaul required. However, if the head has not been removed, back out all of the head bolts and lift the head free of the powerhead. Many, but not all, heads have a thermostat installed. In addition to the thermostat, the engine may have a thermostat bypass valve. These two items are easily removed, inspected and cleaned. Normally, if a thermostat is not functioning properly, it is almost always stuck in the open position. An engine operating at too low a temperature is almost as much a problem as an engine running too hot. Therefore, during a major overhaul, good shop practice dictates to replace the thermostat and eliminate this area as a possible problem at a later date. Lay a piece of fine sandpaper or emery paper on a flat surface (such as a piece of glass) with the abrasive side facing up. With Removing the thermostat from the head. the machined face of the head on the sandpaper, move the heac' in a circular motion to dress the surface. This procedure wH! also indicate any '9high'u or 19low19 spots. Check the spark plug opening/s to be sure the threads are not damaged. .... iost marine dealers can insert a heii-coil into a spark plug opening if the threads have been damaged. Cn many engines, a sending unit is installed in the hea.c to '.varn the operator if the engine begins to run too hot. The light Cylinder block water passages corroded preventing Operating an engine without the thermostat and proper circulation of coolant water. thermostat cover installed to check the coolant water flow. on the dash can be checked by turning the ignition switch to the ON position, and then ground the wire to the sending unit. The light should come on. If it does not, replace the bulb and repeat the test. 3-5 REED SERVICE DESCRIPTION All two-cycle engines have individual ignition and fuel delivery for each cylinder. This means the cylinder is operating independently of the others. The cylinder consists of a top seal, the cy Iinder, the center seal, and the lower seal. This means each cylinder is completely sealed off from the others. Therefore, with a two-cylinder powerhead, two sets of reeds are installed, one for each cylinder. These reeds may be installed on a reed plate or with a reed box, depending on the model engine. One carburetor provides fuel to both sets of reeds. The reed arrangement operates in much the same manner as the reed in a saxophone or other wind instrument. At rest, the reed is closed and seals the opening to which it is attached. In the case of an outboard engine, this opening is between the crankcase and the carburetor. The reeds are mounted in the intake manifold, just behind the carburetor. Actual Operation The piston creates vacuum and pressure as it moves up and down in the cylinder. As 2-CYCLE INTAKE PORT ABOUT TO OPEN PRESSURE IN CRANKCASE FUEL IN CRANKCASE REED VALVE (CLOSED EXHAUST Diagram to illustrate operation of a two-cycle engine. REED SERVICE 3-7 BROKEN REED VALVE Cross-section of a cylinder to illustrate a broken reed in the crankcase. the piston moves upward, a vacuum is created in the crankcase pulling the reed open. On the compression stroke, when the piston moves downward, the reed is forced closed. Reed Designs A wide range of reeds, reed plates, and reed box installations may be found on an outboard unit, due to the varying designs of the engines. All installations employ the same principle and there is no difference in their operation. Broken Reed A broken reed is usually caused by metal fatigue over a long period of time. The failure may also be due to the reed flexing too far because the reed stop has not been adjusted properly or the stop has become distorted. If the reed is broken, the loose Reed box with a broken reed. 3-8 POWERHEAD Reed stops centered over the reeds. piece MUST be located and removed, before the engine is returned to service. The piece of reed may have found its way into the crankcase, behind the bypass cover. If the broken piece cannot be located, the powerhead must be completely disassembled until it is located and removed. The accompanying illustration depicts how a broken reed \'llill cause a backflow through the carburetor. An excellent check for a broken reed on an operating engine is to hold an ordinary business card in front of the carburetor. Under normal operating conditions, a very small amount of fine mist will be noticeable, but if fuel begins to appear rapidly on the card from the carburetor, one of the reeds is broken and causing the backflow through the carburetor and onto the card. A broken reed will cause the engine to operate roughly and with a "pop" back through the carburetor. Reed Stops If the reed stops have become distorted, the most effective corrective action is to replace the stop instead of making an attempt at adjustment. DIMPLE Close view showing the dimple on the reed plate. The reed leaves must straddle the dimple and be centered over the openings for proper operation. Reed to Base Plate Check The specified clearance of the reed from the base plate, when the reed is at rest, is 0.010" (0.254 mm) at the tip of the reed. An alternate method of the checking the reed clearance is to hold the reed up to the sunlight and look through the back side. Some air space should be visible, but not a great amount. If in doubt, check the reed at the tip with a feeler gauge. The maximum clearance should not exceed 0.010" (0.254 mm). The reeds must NEVER be turned over in an attempt to correct a problem. Such action would cause the reed to flex in the opposite direction and the reed would break in a very short time. REED VALVE ADJUSTMENT In many instances, the reec' is placed on the reed plate in such a manner to cover the openings in the plate. As shown in the accompanying illustration, a. small indent is manufactured into the face of the plate. The leaves of the reed should be centered on this identation for proper operation. If the - '-,,. s- Using a feeler gauge to measure the clearance between the reed tip and the reed plate. V-type reed box installed on the 9.5 hp engines. reed is being replaced, both reeds AND the reed stops should be replaced as a set. V-Type Reed Boxes As the name implies, these reed boxes are shaped in a "V" with a set of reeds and stops on both arms of the "V". If a problem develops with this type reed box, it is strongly recommended that the complete assembly be replaced --reeds, box, and stops. The assembly may be purchased as a complete unit and the cost will usually not exceed the time, effort, and problems encountered in an attempt to replace only one part. CLEANING AND SERVICE Always handle the reeds with the utmost care. Rough treatment will result in the reeds becoming distorted and will affect their performance. Wash the reeds in solvent, and blow them dry with compressed air from the BACK SIDE ONLY. Do not blow air through the ' reed from the front side. Such action would cause the reed to open and fly up against the reed stop. Wipe the front of the reed dry with a lint free cloth. Clean the base plate thoroughly by removing any old gasket material. Secure the reed blocks together with screws and nuts tightened to the torque value given in the Appendix. Check for chipped or broken reeds. Observe that the reeds are not preloaded or standing open. Satisfactory reeds will not adhere to the reed block surface, but still REED VALVE ADJUSTMENT 3-9 Front view of a reed plate with the two sets of reeds and reed stops in place. there is not more than 0.010" (0.254 mm)clearance between the reed and the block surface. DO NOT remove the reeds, unless they are to be replaced. ALWAYS replace reeds in sets. NEVER turn used reeds over to be used a second time. Check the reed location over the reed block, or plate openings to be sure the reed is centered. The reed assemblies are then ready for installation. Small Engines Disassemble the reed block by first removing the screws securing the reed stops and reeds to the reed block, and then lifting the reed stops and reeds from the block. Clean the gasket surfaces of the reed block or plate. Check the surfaces for deep grooves, cracks, or any distortion that could Front view of the reed box showing the Phillips screws that must be removed before the box can be Reed stop installation with flat bars acting as the removed from the plate. reed stop. The bars are the sam e width as the reed. 3-10 POWERHEAD cause leakage. Replace the reed block or plate if it is damaged. After new reeds have been installed, and the reed stop and attaching screws have been tightened to the required torque value, check the new reeds as outlined in the following paragraphs. Check to be sure the reeds are not preloaded. They should not adhere to the block or plate, and still the clearance between the reed and the block surface, should not be more than 0.010" (0.254 mm). DO NOT remove the reeds, unless they are to be replaced. ALWAYS replace reeds in sets. NEVER turn used reeds over to be used a second time. Lay the reeds on a flat surface and measure all the reed stops. If there is a great difference between the stops, the entire reed stop assembly should be replaced. Any attempt to bend and get all the stops equal and level would be almost impossible. INSTALLATION Procedures to install the reeds to the powerhead will be found in Section 3-14, Cylinder Block Service, under Reed Box Installation. Using a feeler gauge to measure the clearance between the reed tip and the reed plate. 3-6 BYPASS COVERS On some small horsepower units the powerhead does not contain bypass covers. The bypass cover actually covers the passageway the fuel travels from the cr ankcase _ up the side of the powerhead and mto the cylinder. Seldom does a bypass cover cause any problem. On some models, a fuel pump may be attached to one of the bypass covers. During a normal overhaul, the bypass covers should be removed, cleaned, and new gaskets installed. Identify the covers to . ensure installation in the same locat1on from which they are removed. Close view showing the dimple on the reed plate. Removing the bypass cover from a typical power The reed leaves must straddle the dimple and be head. centered over the openings for proper operation. INSTALLATION Procedures to install the bypass covers to the powerhead will be found in Section 314, Cylinder Block Service, under Bypass Cover and Exhaust Cover Installation. 3-7 EXHAUST COVER The exhaust covers are one of the most neglected items on any outboard engine. Seldom are they checked and serviced. Many times an engine may be overhauled and returned to service without the exhaust covers ever having been removed. One reason the exhaust covers are not removed is because the attaching bolts usually become corroded in place. This means they are very difficult to remove, but the work should be done. Heat applied to the bolt head and around the exhaust cover will help in removal. However, some bolts may still be broken. If the bolt is broken it must be drilled out and the hole tapped with new threads. The exhaust covers are installed over the exhaust ports to allow the exhaust to leave the powerhead and be transferred to the exhaust housing. If the cover was the only item over the exhaust ports, they would become so hot from the exhaust gases they might cause a fire or a person would be severely burned if they came in contact with the cover. EXHAUST COVER 3-11 The inner exhaust plate and exhaust cover from a 40hp, 50hp, 55hp, or 60hp powerhead. Therefore, an inner plate is installed to help dissipate the exhaust heat. Two gaskets are installed --one on either side of the inner plate. Water is channeled to circulate between the exhaust cover and the inner plate. This circulating water cools the exhaust cover and prevents it from becoming a hazarcl. On some early rr>oclel outboards, the inner plate was constructed of aluminum. Unfortunately, the aluminum would corrode through, especially in a salt water enviroment, and then water could enter the lower cylinder and cause a powerhead failure. The accompanying illustration clearly shows an inner plate corroded Removing the inner plate from a 40hp, 50hp, 55hp, or Removing the exhaust cover from an early power60hp powerhead. head. 3-12 POWERHEAD through, allowing water to enter the lower cylinder. To correct this corrosion problem, the inner plate is now made of stainless steel material. A thorough cleaning of the inner plate behind the exhaust covers should be performed during a major engine overhaul. If the integrity of the exhaust cover assembly is in doubt, replace the complete cover including the inner plate. On powerheads equipped with the heat/electric choke, a baffle is installed on the inside surface of the inner plate. This baffle is heated from the engine exhaust gases. Air passing through the baffle heats the choke and allows the choke to open as engine temperature rises. CLEANING Clean any gasket material from the cover and inner plate surfaces. Check to be sure the water passages in the cover and plate are dean to permit adequate passage of cooling water. Inspect the inlet and outlet hole in the powerhead to be sure they are dean and free of corrosion. The openings in the powerhead may be cleaned with a small size screwdriver. Clean the area around the exhaust ports and in the webs running up to the exhaust ports. Carbon has a habit of forming in this area. The exhaust area of the powerhead, open for inspection and cleaning. INSTALLATION Procedures to install the exhaust covers will be found in Section 3-14, Cylinder Block Service, under Bypass Cover and Exhaust Cover lnst allation. Removing the inner plate from an early powerhead. Using the proper tools to remove the top seal. TOP SEAL 3-13 3-8 SEAL -TOP AND BOTTOM The top seal maintains vacuum and pressure in the crankcase at the top cylinder. REMOVAL This seal can only be removed using one of two met hods. The first, is by using a special puller while the powerhead is still assembled. If the puller is used, thread the end of the puller into the seal. After the puller is secured to the seal, remove the seal from the powerhead by tightening the center screw on the puller. DO NOT attempt to use any other type of tool to remove this seal or the powerhead flanges will be damaged. If the flanges are damaged, the block must be replaced. The second method is to remove the seal during powerhead disassembling. After the crankcase cover has been removed, the seal will be loose and can be easily removed by holding onto the bearing and prying the seal out. INSTALLATION To install the seal with the powerhead assembled, coat the outside diameter of the Pressing a new seal into a bearing. seal with OMC Seal Compound. Use the special tool to tap the seal EVENLY into place around the crankshaft. If the powerhead has been disassembled, a socket or other similar type tool of equal diameter as the seal may be used to tap it into the bearing. If the powerhead being Using the proper tools to install the top seal. Powerhead lower seal installed on the driveshaft. 3-14 POWERHEAD serviced does not have the seal in the bearing, lay the seal in the recess of the block. When the crankcase cover is installed, the seal will be in place. BOTTOM 'SEAL The bottom seal has equal importance as the top seal. This seal is installed to maintain vacuum and pressure in the lower half of the crankcase for the lower cylinder. The bottom seal will vary, depending on the model engine being serviced. The following procedures and accompanying illustrations cover the most common Johnson/Evinrude bottom seal installed. Seal Mounted on the Driveshaft When the powerhead is removed, observe around the driveshaft at the lower end, and the seal will be visible. The seal consists of a gasket, plate, an 0-ring, lower seal bearing, spring, washer, and a pin. The pin is installed through the driveshaft and holds the seal upward and in place. As the powerhead is lowered down over the driveshaft during installation, the seal is held in place and will hold the vacuum and pressure created when the engine is operating. Removal With the powerhead assembled, it is a simple matter to reach into the exhaust housing and remove the seal and then replace the gasket and 0-ring. Check the spring, to be sure it is not distorted, and the washer for damage. Seal Mounted on the Crankshaft This bottom seal prevents exhaust fumes from entering the crankcase, and holds pressure and vacuum inside. The seal consists of Removing the 0-ring from the quadrant ring. These two items form the bottom crankshaft seal. a quadrant ring, 0-ring, retainer washer, spring, another washer, and a snap ring. Removal To remove this seal from the lower end of the crankshaft, use a pair of Tru-arc pliers and CAREFULLY remove the snap ring. TAKE CARE not to lose any of the parts due to the spring pressure against the snap ring. Notice how the quadrant 0-ring fits inside the seal. This ring is also removable. Observe how the seal has a raised edge on one side. This raised edge MUST face upward when the seal is installed. INSPECTION Check to be sure the spring has good tension. Check to be sure the washers are not distorted. The quadrant ring should be DISCARDED and a new one installed. Good shop practice dictates the quadrant seal be replaced each time the lower seal is serviced. Check the groove in the lower end of the crankshaft where the truarc ring fits. If the groove is not clean, the ring will snap out and the lower sealing qualities will be lost. If the groove is badly corroded, the crankshaft must be replaced. A new 0-ring and quadrant ring are installed onto Using a pair of Truarc pliers to remove the snap ring the crankshaft with the raised edge of the quadrant ring from the crankshaft. facing UPWARD when installed. MAIN BEARING BOLTS 3-15 Remove the seal and D-ring from the cap of a 40hp, 50hp, 55hp, or 60hp powerhead. Seal in a Cap Many of the larger horsepower powerheads have the seal installed in a cap. The cap is bolted to the bottom of the powerhead. The four bolts securing the cap must be removed before the crankcase cover can be removed. The cap is then removed after the cover has been removed from the cylinder block. The seal can be punched out and new ones installed without difficulty. 3-9 CENTERING PINS All Johnson/Evinrude outboard engines have at least one, and in most cases two, centering pins installed through the crankcase cover. These pins index into matching holes in the powerhead block when the crankcase cover is installed. These pins center the crankcase cover on the powerhead block. Cylinder block with the two centering pins installed. Removing a centering pin from the cylinder block. The centering pins are tapered. The pins must be carefully checked to determine how they are to be removed from the cover. In most cases the pin is removed by using a center punch and tapping the pin towards the carburetor or intake manifold side of the crankcase. When removing a centering pin, hold the punch securely onto the pin head, then strike the punch a good hard forceful blow. DO NOT keep beating on the end of the pin, because such action would round the pin head until it would not be possible to drive it out of the cover. Centering pins are the first item to be installed in the cover when replacing the crankcase cover. 3-10 MAIN BEARING BOLTS AND CRANKCASE SIDE BOLTS The main bearing bolts are installed through the crankcase cover into the powerhead block. Most engines have two bolts installed for the top main bearing, two for the center main bearing, and two for the lower main bearing. Removing the main bearing bolts from the power head. 3-16 POWERHEAD In many cases the upper and lower main bearing bolts are DIFFERENT lengths. Therefore, take time to tag and identify the bolts to ensure they will be installed in the same location from which they were remov ed. · The crankcase side bolts are installed along the edge of the crankcase cover to secure the cover to the cylinder block. These bolts usually have a 7I16" head and all must be removed before the crankcase cov er can be removed. Remove the crankcase side bolts. Remove the main bearing bolts. Two bolts installed in the center are behind the reeds. Normally these two are not actually bolts, but Allen head screws. All six main bearing bolts must be removed before the crankcase cover can be removed. INSTALLATION Main bearing bolt and the crankcase side bolt installation is given in Section 3-14, Cylinder Block Assembling, under Main Bearing and Crankcase Side Bolt Installation. 3-11 CRANKCASE COVER REMOVAL After all side bolts and main bearing bolts have been removed, use a soft-headed mallet and tap on the bottom side of the crankshaft. A soft, hollow sound should be heard indicating the cover has broken loose Removing the crankcase cover from a 40hp, 50hp, 55hp, or 60hp powerhead. from the crankcase. If this sound is not heard, check to be sure all the side bolts and main bearing bolts have been removed. NEVER pry between the cover and the crankcase or the cover will surely be distorted. If the cover is distorted, it will fail to make a proper seal when it is installed. Once the crankshaft has been tapped, as described, and the proper sound heard, the cover will be jarred loose and may be removed. CLEANING AND INSPECTING Wash the cover with solvent, and then dry it thoroughly. Check the mating surface to the cylinder block for damage that may affect the seal. Cleaning the powerhead surface of a 40hp, 50hp, Cylinder block after the crankcase cover has been 55hp, or 60hp powerhead. Notice the labyrinth seal at removed. the center and bottom main bearings. RODS AND PISTONS 3-17 Crankcase cover with the labyrinth seal area clearly visible. Inspect the labyrinth seal grooves at the center main bearing area to be sure they are clean and not damaged in any manner. INSTALLATION Installation procedures for the crankcase cover are given in Section 3-llJ., Cylinder Block Service, under Crankcase Cover Installation. 3-12 CONNECTING RODS AND PISTONS The connecting rods and their rod caps are a MATCHED set. They absolutely MUST be identified, kept, and installed as a set. Under no circumstances should the connecting rod and caps be interchanged. Therefore, on a multiple piston engine, TAKE TIME AND CARE to tag each rod and rod cap; to keep them together as a set while they are on the bench; and to install them into the same cylinder from which they were removed as a set. Rod and rod cap with the two alignment dimples shown. Rod and rod cap with the alignment line marks shown. The connecting rod and its cap on 15 hp to early 40 hp engines are manufactured as a set --as a single unit. After the complete rod and cap have been made, two holes are drilled through the side of the cap and rod, and the cap is then fractured from the rod. Therefore, the cap must always be installed with its original rod. The cap half of the break can ONLY be matched with the other half of the break on the ORIGINAL rod. The rods and caps on the smaller horsepower engines are made of aluminum with babbitt inserts. These rods and caps are manufactured as two separate items. Inspect the rod and the rod cap before removing the cap from the crankshaft. Under normal conditions, a line or a dot is A punch points to the fractured break of a rod and its cap. The rod and cap must be matched during installation. 3-18 POWERHEAD visible on the top side of the rod and the cap. This identification is an assist to assemble the parts together and in the proper location. Observe into the block and notice how the rods have a "trough". Also notice the hole in the rod near where the wrist pin passes through the piston. On many rods there is also a hole in the rod at the crank end. These two holes MUST ALWAYS face upward during installation. REMOVAL To remove the rod bolts from the cap, it is recommended to loosen each bolt just a little at-a-time and alternately. This procedure will prevent one bolt from being completely removed while the other is still tightened to its recommended torque value. Such action may very likely warp the cap. Remove the bolts as described in the previous paragraph, and then CAREFULLY remove the rod cap to prevent loosing the needle bearings installed under the cap, if used. Remove the needle bearings and cages, if used, from around the crankshaft. Count the needle bearings and insert them into a separate container --one container for each rod, with the container clearly identified to ensure they will be installed with the proper rod at the crankshaft journal from which they were removed. Removing the rod cap from the rod. Tap the piston out of the cylinder from the crankshaft side. Immediately attach the proper rod cap to the rod and hold it in place with the rod bolts. The few minutes involved in securing the cap with the rod will ensure the matched cap remains with its mating rod during the cleaning and assembling work. Identify the rod to ensure it will be installed into the cylinder from which it was removed. Remove and identify the other rod caps, needle bearings and cages, and rods with pistons, in the same manner. DISASSEMBLING Before separating the piston from the rod, notice the location of the piston in relation to the rod. Observe the hole in the rod trough on one side of the rod near the wrist pin opening and another at the lower end. These holes must face toward the TOP of the engine during installation. Removing the bolts from the rod cap. Identifying word "LOOSE" on the inside of the piston skirt and the hole in the rod at the wrist pin end. The wrist pin must be driven from the loose side of the piston out the tight side, as described in the text. RODS AND PISTONS 3-19 Close view of a piston with the slanted edge and sharp edges identified. The piston can only be installed one way for proper operation. Observe the slanted edge and the sharp edge of the dome-type piston. The slanted edge MUST face toward the exhaust side of the cylinder and the sharp edge toward the intake side during installation. Pistons installed in the block of a 40hp, 50hp, 55hp or 60hp powerhead. The word "UP"embossed on the piston must be at the top of the cylinder, as shown. Pistons installed in the powerhead of a 40hp, 50hp, 55hp, or 60hp unit. The word "UP" embossed on the piston must be at the top of the cylinder, as shown. If servicing a 40 hp, 50 hp, 55 hp, or 60 hp powerhead, carefully observe the hole in the rod near the wrist pin and the relationship of the irregular cutouts in the piston skirt. Only in this position will this relationship exist. The rod and piston MUST be assembled in this manner or the engine will run VERY poorly. When the rod is installed to the piston, the relationship of the rod can only be one way. The rod holes must face upward and the piston must face as described in the previous paragraph. Observe into the piston skirt. On most model pistons, notice the "L" stamped on the boss through which the wrist pin passes. The letter mark identifies the "loose" side Piston with the word "LOOSE" embossed on the inside surface of the skirt. 3-20 POWERHEAD A broken rod, possibly caused by inadequate oil delivery or the powerhead operated in a RUNAWAY condition (excessive rpm under a "No Loacl' condition). of the piston and indicates side of the piston from which the wrist pin must be driven out without damaging the piston. Some pistons may have the full word ''LOOSE" stamped on the inside of the piston skirt. If the piston does not have the ''L n or the word"LOOSE"stamped, the wrist pin may be driven out in either direction. It may be necessary to heat the piston in a container of boiling water in order to press the wrist pin free. Remove the retaining clips from each end of the wrist pin. Some clips are spring wire type and may be worked free of the piston using a screwdriver. Other model pistons have a truarc snap ring. This type of ring can only be successfully removed using a pair of tr uarc pliers. Place the piston in an arbor press using the PROPER size cradle for the piston being serviced, and with the LOOSE side of the piston facing UPWARD. The wrist pin must be driven out FROM the loose side. This may not seem reasonable, but there is a very simple explanation. Heating a piston in hot water to expand the metal slightly. By placing the piston in the arbor press cradle with the tight side down, and the arbor ram pushing from the loose side, the piston has good suport and will not be distorted. If the piston is placed in the arbor press with the loose side down, the piston would be distorted and unfit for further service. HOLD ING BLOCK Removing the wrist pin Truarc snap ring from the piston. Removing the wrist pin using a holding block. RODS AND PISTONS 3-2 1 Many rods have a wrist pin bearing. Some are caged bearings and other are not. TAKE CARE not to lose any of the bearings when the wrist pin is driven free of the piston. Alternate Removal Method If the piston does not have the ''L" or the word''LOOSE''stamped, the wrist pin may be driven out in either direction. If an arbor press or cradle is not available, proceed as follows: Heat the piston in a container of very hot water for about ten minutes. Heating the piston will cause the metal to expand ever so slightly, but ease the task of driving the pin out. Assume a sitting position in a chair, on a box, whatever. Next, lay a couple towels over your legs. Hold your legs tightly together to form a cradle for the piston above your knees. Set the piston between your legs with the"LOOSE"side of the piston facing upward. Now, drive the wrist pin free using a drift pin with a shoulder. The drift pin will fit into the hole through the wrist pin and the shoulder will ride on the edge of the wrist pin. Use sharp hard blows with a -·' TOWEL ACROSS LEGS Needle bearings and cages unfit for further service. hammer. Your legs will absorb the shock without damaging the piston. If this method is used on a regular basis during the busy season, your legs will develop black-andblue areas, but no problem, the marks will disappear in a few days. ROD INSPECTION AND SERVICE If the rod has needle bearings, the needles should be replaced anytime a major overhaul is performed. It is not necessary to replace the cages, but a complete NEW set of needles should be purchased and installed. Place each connecting rod on a surface plate and check the alignment. If light can be seen under any portion of the machined surfaces, or if the rod has a slight wobble on - the plate, or if a 0.002" feeler gauge can be inserted between the machined surface and the surface plate, the rod is bent and unfit for further service. Rod, rod cap, wrist pin, and wrist pin bearing, after removal. Removing the wrist pin using a drift pin. The piston can be supported between your legs as described in the text. Testing two rods at the wrist pin end for warpage. to the waiting crankshaft journal, then hammers it. to the waiting crankshaft journal, then hammers it. 3-22 POWERHEAD Testing two rods at the rod cap end for warpage. Inspect the connecting rod bearings for rust or signs of bearing failure. NEVER intermix new and used bearings. If even one bearing in a set needs to be replaced, all bearings at that location MUST be replaced. Inspect the bearing surface of the rod and the rod cap for rust and pitting. Inspect the bearing surface of the rod and the rod cap for water marks. Water marks are caused by the bearing surface being subjected to water contamination, which causes "etching". The "etching" will worsen VERY rapidly. Inspect the bearing surface of the rod and rod cap for signs of spalling. Spalling is the loss of bearing surface, and resembles A crankshaft cleaned and ready for installation. Badly rusted and corroded crankshaft from a submerged engine. This crankshaft is no longer fit for service. flaking or chipping. The spalling condition will be most evident on the thrust portion of the connecting rod in line with the 1-beam. Bearing surface damage is usually caused by improper lubrication. Check the bearing surface of the rod and rod cap for signs of chatter marks. This condition is identified by a rough bearing surface resembling a tiny washboard. The condition is caused by a combination of lowspeed low-load operation in cold water, and is aggravated by inadequate lubrication and improper fuel. Under these conditions, the crankshaft journal is hammered by the connecting rod. As ignition occurs in the cylinder, the piston pushes the connecting rod with tremendous force, and this force is transferred to the connecting rod journal. Since there is little or no load on the crankshaft, it bounces away from the connecting rod. The crankshaft then remains immobile for a split second, until the piston travel causes the connecting rod to catch up Installing the rod cap onto the rod in preparation for cleaning the inside surface. The cap MUST always be kept with its matching rod. Piston badly scored and no longer fit for service. In some instances, the connecting rod crankpin bore becomes highly polished. While the engine is running, a "whirr" and/or "chirp" sound may be heard when the engine is accelerated rapidly from idle speed to about 1500 rpm , then quickly returned to idle. If chatter marks are discovered, the crankshaft and the connecting rods should be replaced. Inspect the bearing surface of the rod and rod cap for signs of uneven wear and possible overheating. Uneven wear is usually caused by a bent connecting rod. Overheating is identified as a bluish bearing surface color and is caused by inadequate lubrication or operating the engine at excessive high rpm. Inspect the needle bearings, if installed. A bluish color indicates the bearing became very hot and the complete set for the rod MUST be replaced, no question. Service the connecting rod bearing sur faces according to the following procedures and precautions: a-Align the etched marks on the knob side of the connecting rod with the etched marks on the connecting rod cap. b-Tighten the connecting rod cap at taching bolts securely. c-Use ONLY crocus doth to clean bearing surface at the crankshaft end of the connecting rod. NEVER use any other type of abrasive doth. d-Insert the crocus cloth in a slotted 3/8" diameter shaft. Chuck the shaft in a drill press and operate the press at high speed and at the same time, keep the connecting rod at a 90° angle to the slotted shaft. e-Clean the connecting rod ONLY enough to remove marks. DO NOT continue once the marks have disappeared. f-Clean the piston pin end of the con necting rod using the method described in Steps d and e, but using 320 grit Carborun dum cloth instead of crocus cloth. HILLS AND VALLEYS Rod cap separated slightly from its matching rod. Notice the matching hills and valleys. RODS AND PISTONS 3-23 PIN . . Testing the wrist pin end of the rod prior to installation. g-Thoroughly wash the connecting rods to remove abrasive grit. After washing, check the bearing surfaces a second time. h-If the connecting rod cannot be cleaned properly, it should be replaced. i-Lubricate the bearing surfaces of the connecting rods with light-weight oil to prevent corrosion. PISTON AND RING INSPECTION AND SERVICE Inspect each piston for evidence of scoring, cracks, metal damage, cracked piston pin boss, or worn pin boss. Be especially critical during inspection if the engine has been submerged. Carefully check each wrist pin to be sure it is not the least bit bent. If a wrist pin is bent, the pin and piston MUST be replaced as a set, because the pin will have damaged the boss when it was removed. 3-24 POWERHEAD Removing the rings from the piston. Check the wrist pin bearings. If the bearing is the pressed-in type, use your finger and determine the bearing is in good condition with no indication of binding or "rough" spots. If the wrist pin bearing is the removable type, the needle should be replaced. Grasp each end of the ring with either a ring expander or your thumbnails, open the ring and remove it from the piston. Many times, the ring may be difficult to remove because it is "frozen" in the piston ring groove. In such a case, use a screwdriver and pry the ring free. The ring may break, but if it is difficult to remove, it MUST be replaced. OBSERVE the pin in each ring groove of the piston. The ends of the ring MUST Cleaning the piston ring grooves. An automotive type ring groove cleaner should NEVER be used. straddle this pin. The pin prevents the ring from rotating while the engine is operating. This fact is the direct opposite of a fourcycle engine where the ring must rotate. In a two-cycle engine, if the ring is permitted to rotate, at one point, the opening between the ring ends would align with either the intake or exhaust port in the cylinder. At that time, the ring would expand very slightly, catch on the edge of the port, and BREAK. Therefore, when checking the condition of the piston, ALWAYS check the pin in each groove to be sure it is tight. If one pin is the least bit loose, the piston MUST be replaced, without question. Never attempt to replace the pin, it is NEVER successful. Check the piston ring grooves for wear, burns, distortion or loose locating pins. During an overhaul, the rings should be replaced to ensure lasting repair and proper engine performance after the work has been completed. Clean the piston dome, ring grooves and the piston skirt. Clean the piston skirt with a crocus cloth. ---------------------11/8"(3mm) -T Measure the diameter of the piston at 118" (3mm) above Close view of a piston showing the ring pin in the the bottom edge. groove. Piston with the wrist pin ready for installation. Notice the ring groove pin. For proper operation and lubrication, the rod must be installed to the piston and the piston into the cylinder as described in the text. Clean carbon deposits from the top of the piston using a soft wire brush, carbon removal solution, or by sand blasting. If a wire brush is used, TAKE CARE not to burr or round machined edges. Wear· a pair of good gloves for protection against sharp edges, and clean the piston ring grooves using the recessed end of the proper broken ring as a tool. NEVER use a rectangular ring to clean the groove for a tapered ring, or use a tapered ring to clean the groove for a rectangular ring. NEVER use an automotive-type ring groove cleaner to dean piston ring grooves, because this type of tool could loosen the piston ring locating pins. TAKE CARE not to burr or round the machined edges. Inspect the piston ring locating pins to be sure they are tight. There is one locating pin in each ring groove. If one locating pin is loose, the piston must be replaced. Never attempt to replace the pin, it is NEVER successful. Oversize Pistons and Rings Scored cylinder blocks can be saved for further service by reboring and installing oversize pistons and piston rings. ONE MORE WORD: Oversize pistons and rings are not available for all engines. At the time of this printing, the sizes listed in the Appendix were available. Check with the parts department at your local dealer for the model engine you are servicing, and to be sure the factory has not deleted a size from their stock. ASSEMBLING CRITICAL WORDS Two conditions absolutely MUST exist when the piston and rod assembly are installed into the cylinder block. The slanted side of the piston must face toward the exhaust side of the cylinder. An automotive ring compressor should NEVER be used to install the rings for a two-cycle engine. RODS AND PISTONS 3-25 INTAKE SIDE The slanted side of the piston MUSI' face the exhaust port and the sharp edge face the intake port. The hole in the rod near the wrist pin opening and at the lovver end of the rod must face UPWARD. Therefore, the rod and piston MUST be assembled correctly in order for the assembly to be properly installed into the cylinder. Soak the piston in a container of very hot water for about ten minutes. Heating the piston will cause it to expand ever so slightly, but enough to allow the wrist pin to be pressed through without difficulty. Before pressing the wrist pin into place, hold the piston and rod near the cylinder block and check to be sure both will be facing in the right direction when they are installed. Pack the wrist pin needle bearing cage with needle bearing grease, or a good grade 3-26 POWERHEAD Wrist pin entering the piston from the "LOOSE" side. of petroleum jelly. Load the bearing cage with needles and insert it into the end of the rod. Slide the rod into the piston boss and check a second time to be sure the slanted side of the piston is facing toward the exhaust side of the cylinder and the hole in the rod is facing upward. Place the piston and rod in the arbor press with the' LOOSE" or stamped ''L" side of the piston facing UPWARD. Press the wrist pin through the piston and rod. Continue to press the wrist pin through until the groove in the wrist pin for the lock ring is visible on Installing the rod and wrist pin bearing into the piston. both ends of the pin. Remove the assembly from the arbor press. Install the retaining ring onto each end of the wrist pin. Some models have a wire ring, and others have a truarc ring. Use a pair of truarc pliers to install the truarc ring. Fill the piston skirt with a rag, towel, shop cloths, or other suitable material. The rag will prevent the rod from coming in contact with the piston skirt while it is laying on the bench. If the rod is allowed to strike the piston skirt, the skirt may become distorted. Assemble the other pistons, rods, and Heating the piston in hot water to expand the metal wrist pins in the same manner. Fill the skirt with rags as protection until the assembly is installed. slightly as an assist to installing the wrist pin. Install the wrist pin using a holding block. Alternate Assembling Method If an arbor press is not available, the piston may be assembled to the rod in much the same manner as described for disassembling. First, · soak the piston in a container of very hot water for about ten minutes. Before pressing the wrist pin into place, hold the piston and rod near the cylinder block and check to be sure both will be facing in the right direction when they are installed. Pack the wrist pin needle bearing cage with needle bearing grease, or a good grade of petroleum jelly. Load the bearing cage with needles and insert it into the end of the rod. Slide the rod into the piston boss and check a second time to be sure the slanted side of the piston is facing toward the exhaust side of the cylinder and the hole in the rod is facing upward. Now, assume a sitting position and lay a couple towels over your lap. Hold your legs tightly together to form a cradle for the piston above your knees. Set the piston between your legs with the LOOSE side of the piston facing upward. Now, drive the CRANKSHAFT 3-27 wrist pin through the piston using a drift pin with a shoulder. The drift pin will fit into the hole through the wrist pin and the shoulder will ride on the end of the wrist pin. Use sharp hard blows with a hammer. Your legs will absorb the shock without damaging the piston. If this method is used on a regular basis during the busy season, your legs will develop black-and-blue areas, but no problem, the marks will disappear in a few days. Continue to drive the wrist pin through the piston until the groove in the wrist pin for the lockring is visible at both ends. Install the retaining spring wire or truarc ring onto each end of the wrist pin. Fill the piston skirt with a rag, towel, shop cloths, or other suitable material. The rag will prevent the rod from coming in contact with the piston skirt while it is laying on the bench. If the rod is allowed to strike the piston skirt, the skirt may become distorted. Assemble the other pistons, rods, and wrist pins in the same manner. Fill the skirt with rags as protection until the assembly is installed. INSTALLATION Piston and rod assembly installation procedures will be found in Section 3-14, Cylinder Block Service under Piston Installation. 3-13 CRANKSHAFT REMOVAL Lift the crankshaft assembly from the block. On some models, especially the The inside of the piston should be filled with rags or Installing the wrist pin without an arbor press. The shop cloths to protect the skirt from being struck by piston can be held in your lap as described in the text. the rod while the piston is out of the cylinder. 3-28 POWERHEAD Crankshaft with the upper, center, and lower main bearings ready to be removed. larger horsepower engines, it may be necessary to use a soft-headed mallet and tap on the bottom side of the crankshaft to jar it loose. As the crankshaft is lifted, TAKE CARE to work the center main bearing loose. This center bearing is a split bearing held together with a snap wire ring. On some models, the bottom half of the bearing may be stuck in the cylinder block. Therefore, the crankshaft and the center main bearing must be worked free of the block together. If servicing a 15 hp to 40 hp powerhead( 40 hp thru 1 983), observe how the center main bearing, and the top and bottom main bearings all have a hole in the outside circumference. Notice the locating pins in the cylinder block. The purpose of this arrangement is to prevent the bearing shell from rotating. During assembling, the holes in the bearings MUST index with the pins in the block. Also notice the grooves in the block on one side of the center main bearing. Observe the grooves in the crankcase cover. This arrangement of grooves forms what is commonly known as a "labyrinth" seal. The grooves fill with oil and/or fuel creating a seal between the cylinders. The 40 hp since 1983, and the 50 hp, 55 hp, and 60 hp powerheads have a pressed in place lower roller bearing. A clamp-type puller is required to removed this bearing. The bearing need not be Removing the Truarc snap ring from the lower bearing of a 40hp, 50hp, 55hp or 60hp powerhead. Using a puller to remove the lower bearing of a 40hp, 50hp, 55hp or 60hp unit. Removing the crankshaft from the block of a 40hp, Using a sleeve-type tool over the end of the drive50hp, 55hp or 60hp powerhead. shaft to install the bearing. removed for cleaning and inspection. Remove this bearing ONLY if the determination has been made that it is unfit for further service. . To install a new bearing, place the bearmg onto the. shaft and press it into place using an arbor press. If an arbor press is not available a socket large enough to fit over the crankshaft could be used to drive the bearing into place. On the smaller horsepower engines, babbitt bearings are used for the center main with needle bearings installed for the upper and lower main bearings. CLEANING AND INSPECTION Inspect the splines for signs of abnormal wear. Check the crankshaft for straightness. Inspect the crankshaft oil seal surfaces to be sure they are not grooved, pitted or scratched. Replace the crankshaft if it is severely damaged or worn. Check all crankshaft bearing surfaces for rust, water marks, chatter marks, uneven wear or overheating. Clean the crankshaft surfaces with crocus cloth. Clean the crankshaft and crankshaft bearing with solvent. Dry the parts, but NOT the bearing, with compressed air. Check the crankshaft surfaces a second time. Replace the crankshaft if the surfaces cannot be cleaned properly for satisfactory service. If the crankshaft is to be installed for service, lubricate the surfaces with light oil. The top and lower bearing may be easily removed from the crankshaft. The center Crankcase cover with the labyrinth seal area clearly visible. CRANKSHAFT 3-29 Badly rusted and corroded crankshaft from a submerged engine. This crankshaft is no longer fit for service. main bearing has a spring steel wire securing the two halves together. Remove the wire, and then the outer sleeve, then the needle bearings. TAKE CARE not to lose any of the needles. The outer shell is a fractured break type unit. Therefore, the two halves of the shell MUST absolutely be kept as a set. Check the crankshaft bearing surfaces to be sure they are not pitted or show any signs of rust or corrosion. If the bearing surfaces are pitted or rusted, the crankshaft and bearings must be replaced. During an engine overhaul to this degree, it is a good practice to remove the seal from the top main bearing. If the same type of seal is used in the bottom main bearing, remove that seal also. A crankshaft cleaned and ready for installation. 3-30 POWERHEAD A crankshaft with a badly corroded "throw". This crankshaft is unfit for further service. Crankshaft with the upper, center, and lower main ASSEMBLING Insert the proper number of needle bearings into the center main bearing cage. Install the outer sleeve over the bearing cage. Check to be sure the two halves of the outer sleeve are matched. Again, these two halves are manufactured as a single unit and then broken. Therefore, the hills and valleys of the break absolutely MUST match during installation. Snap the retaining ring into place around the bear in g. Slide the upper bearing onto the crankshaft journal at the upper end and the lower bearing onto the lower end. Rotate the installed bearings to be sure there is no evidence of binding or rough spots. The crankshaft is now ready for installation. INSTALLATION Installation procedures an• given in Section 3-14, Cylinder Block Service, under Crankshaft Installation. 3-14 CYLINDER BLOCK SERVICE Inspect the cylinder block and cylinder bores for cracks or other damage. Remove The needles and cage of the center main bearing ready for the outside shell to be installed. bearings installed. Check to be sure the snap ring on the center main bearing is installed. carbon with a fine wire brush on a shaft attached to an electric drill or use a carbon remover solution. Use an inside micrometer or telescopic gauge and micrometer to check the cylinders for ·.vear. Check the bore for out-ofround and/ or oversize bore. If the bore is tapered, out-of-round or worn more than 0.003" -0.004" (0.076 mm -0.102 mm) the cylinders should be rebored and oversize pistons and rings installed. GOOD WORDS: Oversize piston weight is approximately the same as a standard size piston. Therefore, it is NOT necessary to rebore all cylinders in a block just because one cylinder requires reboring. The APBA (American Power Boat Association) accepts and permits the use of 0.015" (0.381 mm) oversize pistons. Hone the cylinder walls lightly to seat the new piston rings, as outlined in the Honing Procedures Section in this chapter. If the cylinders have been scored, but are not out-of-round or the sleeve is rough, clean the surface of the cylinder with a cylinder hone as described in Honing Procedures, next section. SPECIAL WORD Cylinder sleeves may be installed on some models, but the cost is very high. HONING PROCEDURES To ensure satisfactory engine performance and long life following the overhaul work, the honing work should be performed with patience, skill, and in the following sequence: a-Follow the hone manufacturer's recommendations for use of the hone and for cleaning and lubricating during the honing operation. lr Pump a continuous flow of honing oil into the work area. If pumping is not practical, use an oil can. Apply the oil generously and frequently on both the stones and work surface. c-Begin the stroking at the smallest diameter. Maintain a firm stone pressure against the cylinder wall to assure fast stock removal and accurate results. d-Expand the stones as necessary to compensate for stock removal and stone wear. The best cross-hatch pattern is obtained using a stroke rate of 30 complete cycles per minute. Again, use the honing oil generously. e-Hone the cylinder walls ONLY enough to de-glaze the walls. f-After the honing operation has been completed, clean the cylinder bores with hot water and detergent. Scrub the walls with a stiff bristle brush and rinse thoroughly with hot water. The cylinders MUST be cleaned well as a prevention against any abrasive material remaining in the cylinder bore. Such material will cause rapid wear of new piston rings, the cylinder bore, and the bearings. g-After cleaning, swab the bores several times with engine oil and a clean cloth, and then wipe them dry with a clean cloth. NEVER use kerosene or gasoline to clean the cylinders. CYLINDER BLOCK 3-3 1 Checking the ring gap clearance by inserting the ring in the cylinder, as described in the text. h-Clean the remainder of the cylinder block to remove any excess material spread during the honing operation. WORDS OF ADVICE If new rings are to be installed, each ring from the package MUST be checked in the cylinder. Errors happen. Men and machines can make mistakes. The wrong size ring can be included in a package with the proper part number. Therefore, check EACH ring, one at-atime as follows: Turn the ring sideways and lower it a couple inches into the cylinder bore. Now, turn the ring horizontal in the cylinder. It is now in its normal operating position, but without the piston. Next, use a feeler gauge and measure the distance (the gap) between the ends of the ring. The maximum and minimum allowable ring gap is listed in the Specifications in the Appendix. Turn the piston upside down and slide it in and out of the cylinder. The piston should slide without any evidence of binding. Using a feeler gauge to check the ring end gap with Resurfacing a cylinder wall using a honing tool. the ring in the cylinder. 3-32 POWERHEAD ASSEMBLING SPECIAL WORD The cylinder block assembling work should proceed quickly and without interruptions. If the work is partially completed and then left for any period of time, sealant may become hard, parts may be moved and their identity for a particular cylinder lost, or an important step may be bypassed, overlooked, or forgotten. The following procedures pickup the work of assembling the cylinder block AFTER the various parts have been serviced and assembled. Procedures for each area are found in this chapter under separate headings. P..TON AND ROD ASSEMBLY INSTALLATION Several different methods are possible to install the piston and rod assembly into the cylinder. The following procedures are outlined for the do-it-yourselfer, working at home without the advantage of special tools. First, purchase a special hose clamp with a strip of metal inside the clamp, as shown in the accompanying illustration. This piece of metal on the inside allows the outside portion of the clamp to slide on the inner strip without causing the ring to rotate. Actually, to our knowledge a Mercruiser dealer is the only place such a clamp may be purchased. At the Mercruiser marine dealer, ask for an exhaust bellows hose clamp. The design of this hose clamp prevents the clamp and the piston ring from turning as the clamp is tightened. DO NOT attempt to use an ordinary hose clamp from an automotive parts house because such a clamp will cause the piston ring to rotate as the clamp is tightened. The ring MUST NOT rotate, because the ring ends must remain on either side of the dowel pin in the ring groove. Next, coat the inside surface of the cylinder with a film of light-weight oil. Coat the exterior surface of the piston with the oil. TAKE TIME Take just a minute to notice how the piston rings are manufactured. Each end of the ring has a small cutout on the inside circumference. Now, visualize the ring installed in the piston groove. The ring ends must straddle the pin installed in each piston groove. As the ring is tightened around the piston, the ends will begin to come together. When the piston is installed into the cylinder bore, the two ends of the ring will come together and the cutout edge will be up against the pin. For this reason, CARE must be exercised when installing the rings onto the piston and when the piston is installed into the cylinder. Install only the bottom ring into the bottom piston groove. Do not expand the ring any further than necessary, to prevent it from breaking. Install the ring into the piston groove with the ends of the ring straddling the pin Proper hose clamp to install the rings if a ring Piston ring groove pins. The ends of the ring must compressor is not available. straddle the pin. CYLINDER BLOCK 3-33 Installing the hose clamp over the ring prior to moving the piston further into the cylinder. in the groove. The ring ends MUST straddle the pin to prevent the ring from rotating during engine operation. In a two-cycle engine, if the ring is permitted to rotate, at one point the opening between the ring ends would align with either the intake or ex haust port in the cylinder, the ring would expand very slightly, catch on the edge of the port, and BREAK. CAREFULLY insert the rod and the pis ton skirt down into the cylinder. GOOD WORDS The following four areas must be checked at this point in the assembling work. a-The piston and rod are being installed into the same cylinder from which they were removed. b-The hole in the rod is facing UPWARD. c-The slanted side of the piston is TOWARD the exhaust side of the cylinder. d-The ends of each piston ring MUST straddle the pin in the piston groove. Push the piston into the cylinder until the bottom ring, just installed, is abou t an inch from the surface of the cylinder block. Tapping a piston into the cylinder of a 40hp, 50hp, 55hp, or 60hp powerhead. Notice the proper type hose clamp used to compress the rings, as explained in the text. Install the hose clamp over the piston and bottom ring. Tighten the hose clamp with one hand and at the same time rotate the clamp back-and-forth slightly with the other hand. This "rocking" motion of the clamp as it is tightened will convince you the ring ends are properly positioned on either side of the pin. Continue to tighten the clamp, and "rocking" the clamp until the clamp is against the piston skirt. At this point, the ring ends will be together and the cutout on each ring end will be against the pin. Tap the piston with the end of a wooden tool handle until the ring enters the cylinder. Remove the hose clamp. Install the remaining rings in the same manner, one at-a-time, making sure the ends of each ring straddle the pin in the piston groove. Notice how the ring pins are staggered 0 from one groove to the next, by 180 . After the last ring has been installed and the clamp removed, tap the piston into the bore until the crown is about even with the cylinder block surface. Tapping the piston into the cylinder with a softUsing a ring installer to expand the ring during headed mallet. installation into the piston ring groove. 3-34 POWERHEAD When installing the piston into a small horsepower powerhead, it is possible to compress the ring with the fingers of each hand, and then to push the piston into the cylinder with your thumbs. Install the other pistons in exactly the same manner. Turn the cylinder block upside down with the top of the block to your LEFT. Remove the bolts and rod caps from each rod. Set each rod cap in a definite position to ensure each will be installed onto the rod from which it was removed. Checking the flexibility of the rings through intake port. Checking the flexibility of the rings through the exhaust port. Both pistons installed into a 40hp, 50hp, 55hp or Both pistons installed in the powerhead. The slanted 60hp powerhead. The embossed word "UP" on the piston edge of each piston is facing toward the exhaust port. must be at the top of the cylinder, as shown. CRANKSHAFT INSTALLATION 3-35 Checking the ring tension with a small screwdriver through the exhaust port of a 40hp, 50hp, 55hp, or 60hp power head. CRANKSHAFT INSTALLATION NEEDLE MAIN AND ROD BEARINGS The following procedures outline steps to install a crankshaft with needle upper, center, and lower main bearings. The upper and lower mains are complete bearings and cannot be disassembled. The center bearing is caged. Installation procedures for small horsepower crankshafts with babbitt upper, lower, and center main bearings and with babbitt rod bearings are given in the following sections. Observe the pin installed in each main bearing recess. Notice the hole in each main bearing outer shell. Our ing installation, the hole in each bearing shell MUST index over the pin in the cylinder block. Crankshaft with the upper, lower, and center main bearings installed. Notice the hole in each bearing. Matching pins in the cylinder block must index into these holes during crankshaft installation. Hold the crankshaft over the cylinder block with the upper end to your LEFT. Now, lower the crankshaft into the block, and at the same time, align the hole in each bearing to enable the pin in the block to index with the hole. Rotate each bearing slightly until all pins are properly indexed with the matching bearing hole. Once all pins are indexed, the crankshaft will be properly seated. Apply needle bearing grease to each bearing cage. Coat the rod half of the bearing area with needle bearing grease. Needle bearing grease MUST be used because other types of grease will not thin out and dissipate. The grease must disipate to allow the gasoline and oil mixture to enter and lubricate the bearing. If needle bearing grease is not available, use a good grade of petroleum jelly (Vaseline). Insert the proper number of needle bearings into each cage. Set the bearing cage into the bottom half of the rod. With your Installing the crankshaft into the block of a 40hp, Bearing locating pins in the cylinder block. Each pin 50hp, 55hp, or 60hp powerhead. The holes in the top must index into a hole in the bearing shown in the and center main bearings must index with the pin in the illustration at the top of this column. block. 3-36 POWERHEAD Cage and needle bearings installed into the lower portion of the ro.d. fingers on each side of the rod, pull up on the rod and bring the rod up to the bottom side of the crankshaft. Put one needle bearing on each side of the crankshaft. Using needle bearing grease load the other cage and install the needle bearings into the cage. Lower the cage onto the crankshaft journal. Install the proper rod cap to the rod with the identifying mark or dimple properly aligned to ensure the cap is being installed in the same position from which it was removed. Tighten the rod bolts fingertight, and then just a bit more. Use a "scratchall", pick, or similar tool and move it back-and-forth on the outside surface of the rod and cap. Make the Lowering the cage and needle bearings over the top of the crankshaft. AL I GNMENT DIMPLE Rod and cap showing the alignment dimples. Installing a needle bearing on each side of the Installing the rod cap over the needle bearings and crankshaft. cage . CRANKSHAFT INSTALLATION 3-37 Installing the rod cap bolts, and at the same time checking the cap alignment with the rod using a pick. INCORRECT CORRECT BOSS HARKS Correct and incorrect rod cap alignment. movement across the mating line of the rod and cap. The tool should not catch on the rod or on the cap. The rod cap must seat squarely with the rod. If not, tap the cap until the "scratchall" will move back-andforth on the rod and cap across the mating line without any feeling of catching. Any step on the outside will mean a step on the inside of the rod and cap. Just a whisker of a lip, will cause one of the needle bearings to catch and fail to rotate. The needle will quickly flatten, and the rod will begin to "knock". Needle bearings MUST rotate or the function of the bearing is lost. Tighten the rod cap bolts alternately and evenly in three rounds to the torque value given in the Torque Table in the Appendix. Checking the flexibility of the rings through the exhaust port on a small horsepower powerhead. Tighten the bolts to l/2 the torque value on the first round, to 3/4 the torque value on the second round, and to the full torque value on the third and final round. On each round, check with the pick to be sure the cap remains seated squarely. Install the other rod cap/s in the same manner. After the rods have been connected to the crankshaft, rotate the crankshaft until the rings on one cylinder are visible through the exhaust port. Use a screwdriver and push on each ring to be sure it has spring tension. It will be necessary to move the piston slightly, because all of the rings will not be visible at one time. If there is no spring tension, the ring was broken during installation. The piston must be removed and a new ring installed. Repeat the tension test at the intake port. Check the other cylinder/sin the same manner. Checking the flexibility of the rings through the exhaust port on a 40hp, SOhp, 55hp, or 60hp powerhead, as described in the text. 3-38 POWERHEAD CRANKSHAFT INSTALLATION UNITS W /TOP NEEDLE MAIN BRG AND BABBITT CTR & BOTTOM UNITS W/TOP & BOTTOM NEEDLE BRG AND CENTER BABBITT BRG UNITS'W/ALL BABBITT MAIN BRGS This section provides detailed instructions to install a small horsepower crankshaft with any of the bearing combinations listed in the heading. Some of the powerheads covered in these paragraphs have rod liners, others do not. The procedures pickup the work af ter the piston/s have been installed, as described earlier in this sec tion. ADVICE Before installing the crankshaft, check to be sure each "throw" is clean and shiny. There should be no evidence of corrosion that might damage the "throw" during engine operation. Lower the crankshaft into place in the cylinder block with the long threaded shank end at the top of the cylinder block. (It is a known fact, in more than just a few shops around the country, because of haste, the crankshaft installation work has proceeded with the short end at the top.) The hole in the upper and lower main bearing MUST index into the pin in the cylinder block. Some engines may have a lining arrangement as listed in the heading of this section. The lining is made in two parts. Install the liner half into the rod, then install the bearings as described in the next paragraph. The matching liner is to be installed into the rod cap. Coat the rod half, of the bearing area, with needle bearing grease. Needle bearing grease MUST be used because other types of grease will not thin out and dissipate. The grease must dissipate to allow the gasoline and oil mixture to enter and lubricate the bearing. If needle bearing grease is not available, use a good grade of petroleum jelly (Vasoline). Load the rod half of the rod bearing with needle bearings. Next, bring the rod up to the crankshaft rod journal. Coat the crankshaft journal with needle bearing grease. Place the needle bearings around the crankshaft jounal. Position the rod cap, with the liners (if used) over the needle bearings. Install the rod cap bolts and lockwashers. Bring the bolts up fingertight, and then just a bit more. If the liners are used, the cap and rod automatically align properly. If liners are not used, a dowel pin is installed in the rod cap. This pin will index into a hole in the rod for proper alignment. Tighten the rod cap bolts alternately and evenly in three rounds to the torque value given in the Specifications in the Appendix. Tighten the bolts to l/2 the torque value on the first round, to 3/4 the torque value on the second round, and to the full torque value on the third and final round. On each round, check with the pick to be sure the cap remains seated squarely. After the rod cap bolts have been tightened to the required torque value and the installation appears satisfactory, bend the bolt locking tabs upward to prevent the bolts from loosening. Install the other rod cap/s in the same manner. Needle bearings installed in the rod cap liner and Rod and cap with the alignment mal'ks visible. around the crankshaft. CRANKSHAFT INSTALLATION 3-39 Rod cap with liner ready for installation around the crankshaft. After the rods have been connected to the crankshaft, rotate the crankshaft until the rings on one cylinder are visible through the exhaust port. Use a screwdriver and push on each ring to be sure it has spring tension. It will be necessary to move the piston slightly, because all of the rings will not be visible at one time. If there is no spring tension, the ring was broken during installation. The piston must be removed and a new ring installed. Repeat the tension test at the intake port. Check the other cylinder/s in the same manner. Rod and cap with the alignment marks visible. CRANKSHAFT INSTALLATION BABBITT MAIN AND ROD BEARINGS Tris sect.iolr! orovicles cletailec' instructions to install a" srr 8ll f>orseDC'\"er crcnksha.ft \vith babbitt upt'er, lower, c>nc1 center main hearings, arcl v..ith r.-a bbitt roc! f.earir>gs. The orocecmes oida.1c the 8.ftert..e pisto../s have been in.stallec, as c'escribed earlier in this sect.iono Lower the crankshaft into place in the cylinder block with the long threaded shank end at the top of the cylinder block. (It is a known fact, in more than just a few shops around the country, because of haste, the crankshaft installation work has proceeded with the short end at the top.) Pull the rod up to the crankshaft journal. Position the rod cap over the crankshaft The locking tabs must be bent upward after the rod cap bol ts have been tightened to the proper torque Tightening the rod cap bolts to the proper torque value. value. 3-40 POWERHEAD Using two hammers to fit the rod cap to the crankshaft. journal. Install the rod cap bolts and lockwashers. Bring the bolts up fingertight, and then just a bit more. Tighten the rod cap bolts alternately and evenly in three rounds to the torque value given in the Torque Table in the Appendix. Tighten the bolts to 1/2 the torque value on the first round, to 3/4 the torque value on the second round, and to the full torque value on the third and final round. On each round, check with the pick to be sure the cap remains seated squarely. Repeat the procedure for the other rod and cap. After the other rod cap has been installed and the bolts tightened to the proper torque value, hold one hammer on one side of the rod and cap, and at the same time tap the other side of the rod and cap with the other hammer. Tap lightly on the top of the cap. Reverse the hammer positions and tap the opposite sides of the rod and cap. This procedure will "fit" the rod and cap to the crankshaft journal. Repeat the "fitting" procedure for the other rod and cap. Once the installation procedure appears satisfactory and all work has been completed, bend the bolt locking tabs upward to prevent the bolts from loosening. CRANKCASE COVER INSTALLATION First, check to be sure the mating surfaces of the crankcase cover and the cylinder block are clean. Pay particular attention to the labyrinth seal grooves in the center main bearing area. The mating surfaces and the seal grooves MUST be free of any old sealing compound or other foreign material. CRITICAL WORDS The rerraimJer of the cylinder block installation work shoulc be oerform e(i WITHOUT interru!Dti0'P. Po not beP,in the work if a. nreak in the sequence is expecterl -coffee, lunch, tea, whatever. floth types of Checking movement of the pistons and crankshaft Installing sealer to the "spaghetti" seal in the crank­with the flywheel temporarily installed. case cover. MAIN BEARING BOLTS 3-4 1 Installing sealer . to the cylinder block when the "spaghetti" seal is not used. sealer wiU b-egin to set almost immediately, therefore, the crankcase cover installation, main hearing bolt installation ancl tightening, and the side bolt installation and tightening MUST move along RAPIDLY. Apply just a. small amour11t of 1000 Sealer into the groove in the cylinder block to ho!cll the "spaghett.i'u seal in place, if usecl. Install a new seal into the groove. After the seal on both sides of the cylinder block has been installed, aooly a light coating of 1000 Sealer to the outside ed..e of the "soa.ghetti" sea.l. SPECIAL NOTE Since 1 ?..0, the cylinder a.nd cra.nkcase assemblies do not ha.ve the grooves on the rrating surfaces for the neoprene "spaghetti" seals. The ne\u sealing method is to use 0f»(: Gel-Sea.! (P/f'l 322702). This new seal is to be usec' on aU 2-cy1inder throu.?;h 6cy! inder models. DO NOT use similar appearing jel-tyoe sealants, since some of them cor11tain fiBers that have a shimming affect. Such shimmin!l' could cause imorooer bearing location, bearing misalignment, or tight armature plate bearings. lay down a small bead of the Gel-Seal along one flange of the crankcase, as shown. Take care to apply sealant inside all bolt holes. Keep the sealant at least 1/4" from the labyrinth seals. U the motor is to be operated the same clay, the surface opposite the one \Vith the Gel-Seal should be sprayed with or..I!C locOuic Primer. \lfait several hours before starting the engine. If LocOuic Primer is not used, the assembly should sit overnie;ht before the engine is started. The remaining installation instructions apply to a.ll powerheads. !"'!ext, lower the crankcase cover into place on the cylinder block. Install the two Two tapered pins installed in the cylinder block. guide centering pins through the cover and into the block. The centering pins are tapered. Therefore, check the crankcase and notice which side has the large hole and which has the small hole. The pin must be .inserted into the large hole first. If the pin is installed into the small hole first, the crankcase cover or the cylinder block will break. MAIN BEARING BOLT AND CRANKCASE SIDE BOLT INSTALLATION Apply a coating of 1000 Sealer to the threads of the main bearing bolts. Install and tighten the main bearing bolts fingertight and then just a bit more. Tighten the main bearing bolts alternately and evenly in three rounds to the torque value given in the Torque Table in Installing the main bearing bolts through the crankcase cover into the cylinder block. 3-42 POWERHEAD the Appendix. Be sure to check the Specifications in the Appendix for the engine being serviced. Tighten the bolts to 1/2 the total torque value on the first round, to 3/4 the total torque value on the second round, and to the full torque value on the third and final round. As an example: If the total torque value specified is 200 ft-lbs, the bolts should be tightened to 100 ft-lbs on the first goaround; to 150 ft-lbs on the second round; and to the full 200 ft-lbs on the third round. Install and tighten the crankcase side bolts to the torque value given in the Appendix. Install the Woodruff key in the crankshaft. Slide the flywheel onto the crankshaft. Rotate the flywheel through several revolutions and check to be sure all moving parts indicate smooth operation without evidence of binding or "rough" spots. Remove the flywheel and the Woodruff key. LOWER SEAL INSTALLATION TYPE ATTACHED TO LOWER END OF CRANKSHAFT This type of seal is attached to the lower end of the crankshaft. On the smaller engines, a seal is used on the crankshaft with a spring, 0-ring, and gasket. These items push up against the bottom of the powerhead to affect the seal. Installing the lower main seal assembly to the crankshaft. Install the quadrant 0-ring into the quad rant re tainer. Apply a small amount of light-weight oil onto the quadrant retainer and 0-ring, and then slide them onto the crankshaft wi th the lip or raised edge of the retainer facing UPWARD upon installation. Slide the large washer, spring, and small washer, on to the crankshaft, and secure them in place with the truarc snap ring. LOWER SEAL INSTALLATION 40 HP SINCE 1983 ALL .50 HP, .5 .5 HP, and 60 HP After the crankshaft and the crankcase cover have been installed, install an 0-ring onto the cap. Cover the 0-ring and the crankshaft with some light-weight oil. Slip the cap over the crankshaft as far as possible. Coat the threads of the attaching bolts with Loctite. Secure the cap in place with the four bolts. Tighten the bolts alternately and evenly. EXHAUST COVER AND BYPASS COVER INSTALLATION Coat both sides of a NEW gasket with 1000 Sealer, and then place the gasket in Using a pair of Truarc pliers to install the Truarc snap ring onto the crankshaft to secure the bottom seal Powerhead lower seal installed on the driveshaft. in place. REED BOX INSTALLATION 3-43 Installing the lower main bearing cap onto the crankshaft of a 40hp, SOhp, SShp, or 60hp powerhead. position on the exhaust side of the cylinder block. Install the inner pia te. Coat both sides of another NEW gasket with sealer ,and then install the gasket and exhaust cover. Secure the exhaust cover in place with the attaching hardware. Coat both sides of a NEW gasket with sealer, and then place it in position on the cylinder block. Install the bypass covers and secure them in place with the attaching hardware. If a fuel pump is used, be sure the same bypass cover is installed in the position from which it was removed. REED BOX INSTALLATION Install the reed box and intake manifold onto the cylinder block. A gasket is usually installed on both sides of the reed box. The reeds and reed stops face inward toward the cylinder. On 15 hp to 40 hp powerheads (40 hp thru 1983), a screw is installed in the center of the reed box into the cylinder block. This center screw is installed first, then the intake manifold is installed and secured in place. Installing the exhaust cover. Installing the inner exhaust plate on a 40hp, SOhp, 55hp, or 60hp powerhead. Installing the intake bypass covers. One is already in place. Installing the intake manifold over the reed plate. 3-44 POWERHEAD HEAD AND POWERHEAD INSTALLATION Place a NEW head gasket in place on the cylinder block. NEVER use automotive type head gasket sealer. The chemicals in the sealer will cause electrolytic action and eat the aluminum faster than you can get to the bank for money to buy a new cylinder block. Install the head bolts and tighten them fingertight, then just a bit more. Tighten the bolts alternately .:..nd evenly in three rounds to the torque value specified in the Appendix. On the first rouncl tighten the bolts to 1/2 the total torque value, on the second round to 3/4 the total torque value, and to the full torque value on the third and final round. Install the assembled powerhead to the exhaust housing and tighten the attaching bolts alternately and evenly in three rounds to the torque value specified in the Appendix. Tigh ten the bol ts to 1/2 the torque value on the first round, to 3/4 the total torque value on the second round, and to the full tcrque value on the third and final round. InstaU all power head accessories including the flywheel, carburetor, magneto, starter, etc.. If any doubts or difficulties are encountered, follow the procedures outlined in the chapter covering the particular component. Connect the fuel lines, wiring, and ba ttery cables. The complete outboard unit is now ready to be started and "broke-in'' according to the procedures outlined in the next section. Tightening the head bolts to the proper torque value. 3-1.5 BREAK-IN PROCEDURES Mount the engine in a test tank or body of water. If this is not possible, connect a flush attachment and garden hose to the lower unit. NEVER operate the engine above idle speed using the flush attachment. If the engine is opera ted above an idle speed, the unit must be IN GEAR, preferable with a test wheel attached to the propeller shaft. If the engine is operated above an idle speed with no load on the propeller, the engine could RUNAWAY resulting in serious damage or destruction of the unit. CAUTION: Water must circulate through the lower unit to the engine any time the engine is run to prevent damage to the water pump in the lower unit. Just five seconds without water will damage the water pump. a-ALWAYS use OMC or BIA certified TC-W oil lubricant. b-For all 1971-84 engines in this manual: use 50:1 oil mixture. c-Since 1985 the Colt, Junior, Ultra, and 2 hp thru 35 hp: first 5 hours of break-in use 50:1 oil mixture. Recommendation is 1/6 pint of oil per gallon of gasoline (50:1). After "break-in", use 100:1 oil mixture. d-Since 1985 --without VRO: during break-in and after, use 50:1 oil mixture. e-NEVER use: automotive oils, premixed fuel of unknown oil quantity, or premixed fuel richer than 50:1 f-When engine starts, CHECK water pump operation. Prior to 1977, a water mist should discharge from the exhaust relief holes at rear of drive shaft housing. Since 1977, a stream of water should discharge from the starboard side. During the first 5 hours of operation, DO NOT operate the engine at full throttle (except for VERY short periods). Perform the break-in as follows: 1-Operate at 1/2 throttle for 2 hours. 2-Operate at any speed after 2 hours BUT NOT at sustained full throttle until another 3 hours of operation. 3-\'Fhile the engine is operating during the initial period, check the fuel, exhaust, and water systems for leaks. 4-Pefer to Chapter 5 for synchronizing procedures. After the test period!, disconnect the fuel line. Remove the engine from the test tank. Install the engine hood. BREAK-IN PROCEDURES 3-45 OMC approved oil for Johnson and Evinrude outboard engines. Only quality grade oil should be used for any engine. The added expense is ridiculously small compared to the cost of the outboard. Filling a six-gallon fuel tank with small quantity of fuel prior to adding the recomm ended amount of oil. OMC rust preventative to be injected into the engine through the carburetor prior to storage. The small cost of this product is well worth the preservation afforded the engine through its use. Adding oil to the fuel in a built-in tank. 3-46 POWERHEAD CYLINDER OIL HEAD SEAL EXHAUST COVER ROLLER 'GASKET CRANKSHAFT PI STON WRI ST PIN CONNECT ING ROD Exploded drawing of a typcial single cylinder powerhead with major parts identified. EXHAUST COVER PLATE GASKET CYL I NDER BLOCK CRANKCASE PIN CONNECT ING ROD Exploded drawing of a 4 hp --1971-77 powerhead with principle parts identified. EXPLODED DRAWINGS 3-47 HEAD SCREW (6) GASKET RING CONNECT ING ROD NEEDLE ROD BEAR ING INSERT CRANKSHAFT END CAP Exploded drawing of a 2. 5hp and 4hp powerhead --1978 and on. Major parts are identified. 3-48 POWERHEAD EXHAUST COVER PLATE HEAD BOLT (6) CYL INDER HEAD GASKET BLOCK PI STON RING PISTON WRIST PIN Exploded drawing of a 4.5 hp --1980-85 and 7.5 hp --1980-83 powerhead with principle parts identified. EXPLODED DRAWINGS 3-49 Exploded powerhead drawing of a 6hp 1971 and on: Bhp --1984 and on. Major parts are identified. 3-50 POWERHEAD HEAD GASKET EXHAUST INTER PLATE ( /// // II) EXPLODED DRAWINGS 3-5 1 Exploded drawing of a 9.9hp and 15hp crankshaft assembly --1974 and on. Major parts are identified. The block is shown on the next page. 3-52 POWERHEAD Exploded drawing of a 9.9hp and 15hp cylinder block --197 4 and on. Major parts are identified. The crankshaft assembly is shown on the previous page. EXPLODED DRAWINGS 3-53 . Exploded powerhead drawzng --25hp --1971 and on and 35hp t"f"ed • 0-RING I I I I I I.... II CENTER MAIN CRANKSHi \.... /KEEPER..WRIST PIN RING !\ i\ ! ..', / n ''' LOWER QUADRAN.... ..ALROO BEARING RING .. W SHER SPRINGH LL SNAP · RINGC) 3-54 POWER HEAD I \ \ I I III I /II // ------, ' ' ' ' ' \\ \ Expo . of the crankshaft assembly for a 2Ohp powerhea d 1971-73 and 1981 and on. Major par ts are identified. EXPLODED DRAWINGS 3-55 GASKE:T CY LINDER HEAD LIE'T BRACKET HOUSL"JG "0"-RING Exploded powerhead drawing --40hp --197 1-76 and 1981-1982. Major. parts are identified. OIL If.. CB ::E.. I ""' '1 .. l mUPPER > 0 . , ' CYLINDER ....':AD CCV!EA CRAN KCASE SEAL NEEDLE BEARING l! R':JLLF:: A .0 ..0 ASSEMBLY WRIST PIN liE I J CRAN KSHAFT GASKETS LIFT / / / u v CONNECTING ROD BEARING . GASKETS CRANKCASE --[' ./' ROD . /r,r.-u. . 3' "-< eoJ ........ , . . .{ . J /' RIO' l' :f' CC M!' ON ENTS ' «.>... ·. : ·-. ·"Yl. Remove the carburetor flange nut from the bowl. 8-../ith a small screwdriver, reach into the bowl cavity and remove the packing glands from the carburetor. 9-Remove the four screws securing the bowl to the carburetor, and then remove the bowl. , PACKING NUT HIGH-SPEED NOZZLE ® 10-Remove the bmv1 gasket from the carburetor. Remove the gasket from the high-speed nozzle. Remove the high-speed nozzle from the carburetor using the proper size screwdriver to prevent possible dan:age to the nozzle. If difficulty is experienced in removing the high-speed nozzle, leave it in place. \1/hen the carburetor is immersed in the carburetor cleaner the nozzle will be dear.ed suitable further service. 11-\iork the hinge pin free of the float and then remove the float. 12-Remove the inlet needle from the seat. Remove the seat and gasket from the carburetor. Further disassembly of the carburetor is not necessary. FLOAT ® INlET NEEDLE VALVE TYPE II CARBURETOR 4-23 GOOD Cross-section drawing to allow comparison of a new needle and seat with one badly worn. Notice how the edges of the worn valve and the seat have become beveled. CLEANING AND INSPECTING NEVER cip rubber parts, plastic parts, (.iaphragms9 or pump plungers in carburetor cleaner. These parts should be cleaned ONLY in solvent, anc' then blown dry with compressed air. Place all metal parts in a screen-type tray and dip them in carburetor cleaner untH they appear completely dean, then blow them dry \Jili th compressed air. GOOD WORDS Since 1..83 crn,c states that carburetor parts should I"YOT be submergec in carburetor cleaner, as has been the practice since VORN Using a Syringe, piece of clear plastic hose, and® Isopropyl Alcohol to clean the idle air bleed system. 4-24 FUEL carburetors were invented. Their approved procedure is to place the parts in a shallow tray anc then spray them with an aerosol carburetor cleaner as depicted i.n the accompanying illustration. A syrihge, short section of dear plastic hose, and Isopropyl Alcohol should be usee to clear passages and jets. Blow out aU passages in the castings with compressed air. Check aH of the parts and passages to be sure they are not clogged or contain any aeposi ts. NEVER use a piece of v'-'ire or any type of pointed instrument to clean d!riHea passages or calibrated holes in a carburetor. .....ove the throttle shaft back-and-forth to check for wear. If the shaft appears to be too loose, replace the complete throttle body because incHviC'ual replacement parts are NOT avaHable. If any part of the float is damaged, the unit must be replaced. Check the float arm needle contacting surface and replace the float if this surface has a groove worn i.n i. t. Inspect the tapered section of the and high-speed adjusting needles anc replace any that have developed a groove. If a high-speed orifice is installed on the carburetor being serviced, check the orifice for cleanliness. The orifice has a stamped number. This number represents a driB size. Check the orifice \vith the shank of the proper size driH to verify the proper orifice is usee:ij. The local c....c dealer will be able to provide the correct size orifice for the engine and carburetor being serviced. ...'ost parts that should be replaced dming a carburetor overhaul are induced in overhaul kits. These kits are available from your local marine dealer. Cne of these kits will contain a matchec fuel inlet needle ana seat. '!'his combination should be replaced each time the carburetor is cisassemblec as a precaution against leakage. • PACK 1 NG r--.... _ ELECTRIC CHOKE I -- 1 -, I I I ASSEMBLY I I I ( e /.; I I I I INLET FLOAT VALVE NOZZLE .. j G..Q ! G i I .... PACK ING NUT l _ --.... -... .... ... -. -... __ I .. I ----..JI HIGH-SPEED I I NEEDLE VALVE Exploded view of a Type II carburetor installed on larger horsepower engines equipped with the all-electric choke. TYPE II CARBURETOR 4-25 ASSEMBLING TYPE ll CARBURETOR Purchase of a carburetor repair kit is almost a must when servicing this unit. All parts required for a complete rebuild, including the necessary gaskets, are contained in the kit. rv;,ost repair kits contain more parts and gaskets than are needed because the kit may be used to service a V\'ide range of carburetor models. 1-Install the NEW inlet seat and gasket into the carburetor base. Take care to use INLET NEEDlE VAlVE the proper size screwdriver as a precaution against damaging the inside surface of the the seat. Apply just a drop of oil into the seat, to prevent the needle from sticking when it is installed. Insert the inlet needle .. CDinto the seat. ..

.. PACKING PACK ING Go . _ .... .. LOW-SPEED ..// // 6!! NUT '_' · ELECTRIC CHOKE NEEDLE VALVE in tne fuel une ·ng a squee ze re type fuel tanl< ust non-pressu f a m,odern £;.:ploded vieW o FUEL TANK 4-53 Typical Jolmson/Evinrude non-pressurized fuel tank. and the two fuel hoses to the pump in the same position from which they were removed. Actually, each fitting is identified by word designation embossed on the pump. The vacuum line is connected to the vacuum fitting; the inlet fuel line from the fuel tank to the inlet fitting on the cover; and the outlet line to the remaining fitting. 4-12 FUEL TANK SERVICE Late model fuel tanks (since about 1959), are not pressurized. A squeeze bulb is used to move fuel from the tank to the carburetor until the engine is operating. Once the engine starts, the fuel pump, mounted on the engine, transfers fuel from the tank to the carburetor. The pickup unit in the tank is sold as a complete unit, but without the gauge and float. 1-To replace the pickup unit, first remove the four screws securing the unit in the tank. Next, lift the pickup unit up out of the tank. 2-Remove the two Phillips screws securing the fuel gauge to the bottom of the pickup unit and set the gauge asid.. for CD installation onto the new pickup unit. If the pickup unit is not to be replaced, dean and check the screen for damage. It is possible to bend a new piece of screen material around the pickup and solder it in place without purchasing a complete new unit. Attach the fuel gauge to the new pickup unit and secure it in place with the two Phillips screws. 3-Clean the old gasket material from fuel tank and old pickup unit (.if the old pickup unit is to be installed for further service). Work the float arm down through the fuel tank opening, and at the same time the fuel pickup tube into the tank. It will probably be necessary to exert a little force on the float arm in order to feed it all into the hole. The fuel pickup arm should spring into place once it is through the hole. Secure the pickup and float unit in place with the four attaching screws. FLOAT Fuel pump pickup assembly. The fuel gauge assembly is not sold as a part of the pickup unit. 4-54 FUEL 4-The primer squeeze bulb can be replaced in a short time. A squeeze bulb assembly, complete with the check valves installed, may be obtained from the local OMC dealer. An arrow is dearly visible on the squeeze bulb to indicate the direction of fuel flow. The sqeeze bulb MUST be installed correctly in the line because the check valves in each end of the bulb will allow fuel to flow in ONLY one direction. Therefore, if the squeeze bulb should be installed backwards (in a moment of haste to get the job done), fuel will not reach the carburetor. 5-To replace the bulb, first unsnap the clamps on the hose at each end of the bulb. Next, pull the hose out of the check valves at each end of the bulb. New clamps are included with a new squeeze bulb. If the fuel line has been exposed to considerable sunlight, it may have become hardened, causing difficulty in working it over the check valve. To remedy this situation, simply immerse the ends of the hose in boiling water for a few minutes to soften the rubber and the hose will then slip onto the check valve without further problems. After the lines on both sides have been installed, snap the clamps in place to secure the line. Check a second time to be sure the arrow is pointing in the fuel flow direction, TOWARDS the engine. 6-Use two ice picks or similar tool, and push down the check valve of the connector and work the 0-ring out of the hole. 7-Apply just a drop of oil into the hole of the connector. Apply a thin coating of oil to the surface of the 0-ring. Pinch the 0-ring together and work it into the hole while simultaneously using a punch to depress the check valve inside the connector. 4-13 ELECTRIC PRIMER CHOKE SYSTEM The electric primer system consists of a solenoid valve, distribution lines, and injec tion nozzles. The nozzles are tapped into the bypass covers. During engine cranking when the choke system is operating, fuel is injected through metered holes in the noz zles directly into the cylinders, instead of being routed in the usual manner through the crankcase. During engine operation, from the fuel tank, the fuel passes through the fuel line, to the fuel pump, and into the carburetor. From the carburetor the fuel and air mix ture passes through the crankcase and into the cylinder. The primer system injects fuel directly into the cylinder. The system is controlled by the "push-in" type key switch. As the key is pushed in, the solenoid is act iva ted, moving a small plunger which ac ts as a pump, injecting fuel through the nozzles directly into the cylinder to assist powerhead startup. If the battery is dead and the choking effect is desired, a lever on the solenoid may be moved to the MANUAL position opening the seat in the valve. When the squeeze bulb is activated, fuel will pass through the nozzles directly into the cylinders. The lever is then re turned to the RUN position during actual cranking of the power head. WORD OF CAUTION If the fuel tank has been exposed to direct sunlight, pressure may have developed inside the tank. Therefore, when the solenoid lever is moved to the MANUAL position, an excessive amount of fuel may be forced into the cylinders. As a safety precaution, under possible fuel tank pressure conditions, the fuel tank cap should be opened slightly to allow the pressure to escape before attempting to start the engine. SOLENOID TESTING Connect an ohmmeter to the solenoid between the blue/white stripe lead and the black (ground) wire. Observe the reading. The ohmmeter should indicate 5.5 + 1.5 ohms. If the reading is not within the prescribed range, the solenoid is defective and must be replaced. ELECTRIC PRII\A.ER CHOKE 4-55 1. Cover 5. Plunger ... Gasket 6. Spring :l. Seal 7. Solenoid body 4. Filler 8. Plunger valve Exploded drawing of a primer solenoid valve. The accompanying illustra tion will be helpful in ordering and replacing parts of the primer choke system. The fuel hoses should be checked to ensure they remain flexible and are clear to permit an adequate fuel supply to pass through. Pay particular attention to any evidence of a crack in a fuel line which may permit fuel to escape and cause a very hazardous condition. OMC tool No. 326623, is available to clean the metered holes in the nozzles. 4-14 MANUAL PRIMER SYSTEM Description of Operation During powerhead operation: from the fuel tank, the fuel passes through the fuel line, to the fuel pump, and into the carburetor where it is mixed with ambient air. From the carburetor, the fuel/air mixture passes through the crankcase and into the cylinder. The manual primer system injects fuel directly into the cylinder. The system is activated by the "push-in" type choke lever. As the lever is pushed in, a small plunger moves inside the cylinder and acts as a pump, injecting fuel through the nozzles directly into the cylinder to assist powerhead startup. TROUBLESHOOTING If the manual primer system is suspected of not functioning correctly, remove the fuel line from the primer at the carburetor fi tting. Place the end of the fuel line just removed into a suitable ·container. Squeeze the fuel tank primer bulb to fill the carburetor bowl with fuel. 4-56 FLEL PLUNGER SHAFT LARGE ASS Y CHOKE 0-R ING WASHER PLUNGER LEVER SHAFT HOLE SPOOL LARGE NUT ( TEHPORAR I L Y VALVE INSTALLED) Plunger shaft assembly removed from the choke The primer choke valve removed from the power housing with major parts identified. head. The large nut is temporarily installed onto the threads of the end cap for safe keeping. Remove the large washer and spring Operate the primer choke lever twice. from the plunger shaft. If fuel squirts from the disconnected fuel line into the con tainer, the manual primer Cleaning and Inspecting system is functioning correctly. If not, a Inspect the grooves of the spool valve kinked or restricted fuel line may be the and the shaft of the plunger for any scratchproblem. es or burrs. Polish away any imperfections The most probable cause of a malfuncusing crocus cloth. If a smooth finish cantioning primer system is internal leakage not be obtained without removing excessive past the 0-rings. Therefore if the primer material, replace the spool valve and plungitself is still suspec ted, precede to the foler assembly. lowing paragraph to service the primer sysInspect the condition of the plunger tem. spring, replace as required. Two one-way valves, one at each fuel SERVICING MANUAL PRIMER fitting, can be tested by blowing through them in turn. Each valve is functioning Removal correctly if it allows air to pass one direc Disconnect and plug the inlet and outlet tion, but not in the other direction. If a fuel lines to prevent loss of fuel and convalve allows air to be drawn both in and out, tamination. Remove the choke lever from the valve is defective. Individual valves are the plunger. Back off the large nut securing not servicable. The primer body must be the choke assembly to the lower cowling and replaced. lift the assembly free of the powerhead. Pry the retaining clip from the choke body housing. Pull out the end cap, plunger, Assembling and spool valve assembly. Slide the end cap Install the two new 0-r ings around the from the plunger. Remove and discard the spool valve. Slide the spring, followed by 0-ring around the end cap. the large washer and the third 0-ring, over the plunger. Install a new 0-ring over the end cap and place the end cap over the plunger end. Insert the assembly into the SPECIAL WORDS primer housing and install the retaining clip Observe the three small 0-rings, two on to secure everything together. the spool valve and one around the plunger Slide the assembled primer into the shaft. These three 0-rings are made from a opening in the lower cowling and thread the special material and MUST be replaced with large nut over the protruding threads. a genuine OMC replacement part. Matching Tighten the nu t securely. 0-rings will NOT work! Install the fuel line-s to the appropriate fittings and snap the choke lever into the Remove and discard the three 0-rings. vertical hole in the plunger. 4-1.5 OIL INJECTION SYSTEMS INTRODUCTION The purpose of an oil injection system is to mix oil with the fuel in the proper ratio at all power head speeds to ensure adequate lubrication. The system replaces the age old method of manually adding a quantity of oil to the fuel tank. Since 1985, all 40hp, and some 25hp and 30hp units have been equipped with a Vari able Ratio Oil System, commonly referred to as simply VRO. Since 1986, all non-electric start 25hp and 30hp units and all 9. 9hp and 15hp units have been equipped with an oil injection system known as Au to Blend. In 1987 the name was changed to AccuMix. This Accu Mix system is available as an optional ac cessory on all smaller models down to the 4hp. ACCUMIX (AUTOBLEND} DESCRIPTION The AccuMix (AutoBlend) system is located entirely inside the portable fuel tank. A 1-1/2 quart reservoir cannister contains enough oil for almost five tank fulls of fuel. An oil metering pump is located at the base of the cannister. This oil pump is activated by pulses from the fuel pump installed on the powerhead. The oil metering pump automatically blends fuel from the fuel pickup in the portable tank with oil in the reservoir cannister. The oil/fuel mixture passes through a built-in filter also located inside the cannister. A low-oil warning indicator activates a warning horn when the level of oil falls below one pint. If the operator sustains powerhead operation after the warning horn sounds, the fuel supply is automatically cut off to shutdown the powerhead. The powerhead cannot be restarted until oil has been added to the cannister. Procedures to service the AccuMix (AutoBlend) oil injection system begin Page 4-62. VARIABLE RATIO OIL SYSTEM DESCRIPTION The VRO system consists of an oil reservoir (tank), a VRO oil line primer, a pump to move the oil from the tank to the powerhead, a warning horn, a spark arrestor in the pulse hose to the VRO pump, an oil inlet filter, a vacuum switch in the fuel line and VRO SYSTEM 4-57 the necessary hoses and fittings to connect the various items for efficient operation. All connections in the system MUST be airtight to prevent serious damage to the power head. As the name implies, the VRO pump moves oil from the oil reservoir to the powerhead. However, it is a dual pump and also pumps fuel. Pumping action of the pump stops automatically if fuel is not available at the pump for any reason. This automatic pump shutdown feature prevents the carburetors from filling with oil. The warning horn, loca ted in the control box serves two functions. First, as a low oil level warning; The horn will sound for 1/2 second every 20 seconds if the oil tank level reaches 1/4 of the tank's capacity. The low oil warning circuit consists of a sending unit in the oil reservoir, a ground wire to the engine, and a wire to the warning horn through the key switch. Secondly, the warning horn will sound for 1/2 second every 1/2 second to produce a very urgent warning signal. To continue powerhead operation after the no oil warning horn sounds would almost certainly invite serious damage to internal moving parts and powerhead seizure! The spark arrestor on all models is installed in the pulse hose to the VRO pump. This flame arrestor prevents a backfire flame from entering the VRO pump. A clamp positioned on the hose prevents the spark arrestor from migrating up the hose to the pump. 4-58 FLEL GOOD WORDS Anytime the pulse hose is disconnected at the powerhead, TAKE CARE to be sure the spark arrestor remains in the hose. The spark arr..stor MUST be properly positioned in the pulse hose to prevent serious and permanent damage to the VRO pump. The oil inlet filter, located in the VR 0 reservoir oil pickup line, prevents any dirt or foreign material from entering the pump. If the filter should need cleaning, the hose assembly should be removed and reverse flushed using clean solvent. DO NOT attempt to remove the filter because the filter and hose are serviced and replaced as an assembly. NEW POWERHEAD BREAK-IN PROCEDURE A complete new outboard unit, a new power head, or a rebuilt powerhead, must have oil mixed in the fuel tank IN ADDITION to the VRO system. The mixture should be 50:1 (I pint oil to 6 gallons of fuel) and the unit MUST be operated with this mixture during the first 10 hours of service. CRITICAL WORDS To be convinced the VRO system is working properly, the operator should observe a drop in the oil supply in the VRO oil reservoir during the 10-hour break-in period. At the end of the 10 hour period, the powerhead mounted fuel filter should be inspected. Remove any dirt or foreign matter collected in the filter. TROUBLESHOOTING VRO SYSTEM This short section list a few of the probable problems that might occur in the system with suggested corrective action. The next section --SERVICING outlines in de tail how the tests and service work is to be performed. Warning Horn Sounds a-Oil level in the oil reservoir is below 1/4 full. Add oil to the reservoir. b-Disc on the pickup unit may not be positioned properly. Remove the pickup unit from the reservoir and correct as required. EXPECT OIL TO BE EJECTED SERVICING VRO SYSTEM Servicing consists of making simple tests and checks. A vacuum gauge, pressure gauge, a "T" fi tting, a short section of clear plastic hose, a source of low-pressure compressed air, and a couple of normal shop tools are all that is required to service the VRO system. Check Fuel and Oil Circuits 1-Verify there is more than 1/4 tank of oil in the reservoir. Disconnect the oil inlet hose from the VRO pump. Be prepared to catch oil as it is ejected from the end of the hose. Squeeze the bulb and verify oil is ejected from the open end of the hose. The presence of oil verifies a clear line from the tank to this point. If no oil is ejected, clean the line from the tank and repeat the test. 2-Disconnect the mixed fuel outlet hose from the VRO pump. 3-Insert a ''T" fitting into the end of the hose. Insert a drop of oil into each end of a short section of clear plastic hose. Connect one end of the clear piece of plastic hose to one arm of the "T" and the other end of the hose to the VRO pump. Connect a 0-15 psi pressure gauge to the leg of the "T". Secure the connections with tie straps or hose clamps. Mount the engine in an adequate size test tank or move the boat to a body of wa ter. NEVER operate the engine using a flush attachment for this test. If the engine is operated above idle speed with no load on the propeller, the engine could RUNAWAY resulting in serious damage or destruction of the unit. CAUTION: Water must circulate through the lower unit to the engine any time the engine is run to prevent damage to the water pump in the lower unit. Just five seconds without water will damage the water pump. Start the engine and shift the unit into gear. Advance the throt tie to the near wide open position. Check the pressure gauge. The gauge should indicate 34 kPa (5 psi) to 103 kPa (15 psi) pressure at near full throttle. Each time the pump pulses a small squirt of oil, in addition to the fuel passing through, should be observed in the clear plastic hose discharging from the pump. VRO SYSTEM 4-59 Also, the fuel pressure will drop approximately 6.8 kPa (1 psi) to 13.7 kPa (2 psi) and a "click" sound may be heard each time the pump pulses and discharges oil. Results Fuel pressure satisfactory and oil is observed discharging from the pump through the clear plastic hose: Fuel and oil systems are verified satisfactory. No fuel pressure: Check quantity of fuel in the tank to be sure fuel level reaches the pickup. Add fuel if required. Check fuel line to be sure it is not pinched or kinked restricting fuel flow. Check engine pulse hose to be sure it is not pinched, leaking or disconnected. If all above conditions are satisfactory, the VRO pump is defective and MUST be replaced as a unit. Low fuel pressure: Check for restricted fuel filter at the engine. Check the engine pulse hose to be sure it is not pinched, kinked, leaking, or restricting fuel flow. Squeeze the fuel primer bulb a few times to force a possible fuel vapor-lock out of the system. Warning Horn Check 4-Slide the "boot" down the wire to clear the knife disconnect between the temperature switch and the horn lead. This is not an easy task, but with a pair of needle nose pliers and some patience, it can be done. After the "boot" is clear, disconnect 4-60 FLEL the fitting. Turn the key switch to the ON position. Now, make contact with the lead onto a "clean" place on the powerhead. The horn should sound. If the horn does not sound, there is a problem between the knife disconnect and the remote control box. Clean Vacuum Pulse Hose 5-Remove the vacuum pulse hose. The hose may be cleaned by back-flushing with clean solven t. TAKE CARE to ensure the spark arrestor installed in the hose stays in the hose. A clamp is positioned on the hose to prevent the spark arrestor from migra ting up the hose to the pump. If the hose is damaged and requires replacement, the hose and flame arrestor are purchased as an assembly. The flame arrestor cannot be purchased separately. VRO Pump If troubleshooting and service work indicates the VRO pump to be defective, it must be replaced. The pump cannot be serviced or repaired. The pump is removed by first disconnecting the hoses and then removing the three mounting bolts. Lift the VRO pump free. Engine Mounted Fuel Filter 6-If a fuel inlet filter is moun ted at the engine, this filter can be separated and inspected without removing the hoses. The filter should be inspected at the end of the 10-hour break-in period and at regular intervals as part of normal engine maintenance and service. GOOD WORDS Use ONLY OMC approved clamps on the connections on the inlet side of the VRO pump. A screw type hose clamp will very likely pinch or break the hose causing a suction leak. A tie-wrap will not tighten down to the degree required to prevent a vacuum leak. Vacuum Hose Check This check will verify the system in good condition from the oil pickup to the end of the hose. 7-Remove the VRO pickup unit from the oil reservoir by first removing the four mounting screws and then lifting the pickup straight up and out of the reservoir. Inspect the oil pickup filter, and clean it, if necessary. 8-Purge the system of oil and any small particles of foreign matter by using lowpressure compressed air through the VRO pickup end. 9-Connect a vacuum gauge to the end of the hose. Insert the plug-type nipple that is shipped with the engine (snapped to the fuel hose at the engine) into the VRO pickup. If the plug has been lost, one can be easily made out of suitable material. Secure the plug with a clamp. Pump the gauge until 17.7 em (7") of mercury is indicated. The system should hold the vacuum reading. 10-If the system fails to hold the required vacuum reading, check each connection by applying a small amount of oil at each fitting. The oil will MOMENTARILY stop the leak and the vacuum reading will stop dropping. Carefully inspect the hose for damage. GOOD WORDS OMC STRONGLY recommends that the hose from the primer bulb to the VRO pump be one continuous hose with no fittings between. Therefore, if the hose is damaged, the en tire length should be replaced. Also, VRO SYSTEM 4..I if a dual engine installation is used, DO NOT "T" into the line from the primer bulb. Use a separate oil reservoir, with separate primer bulb and hose to the VRO pump on the second engine --a completely separate system for each engine. 11-If the horn sounds indicating low oil or no oil, the contac ts on the pickup may not be positioned properly. A disc rises slightly when oil is added into the reservoir and lowers slightly as the oil level drops. Check to be sure the contact surface on both sides of the disc is riding equally with the other side to prevent sounding the horn prematurely. If the disc fails to rise, the horn will sound continuously. Clean the float chamber in solvent and the disc should then rise clear of the contacts. 4-62 FLEL Fuel Line Vacuum Test 12-Connect a "T" fitting and vacuum gauge to the outlet hose from the fuel tank, as shown. Check to be sure all fittings and connections are tight. NEVER operate the engine above idle speed using a flush attachment for this test. If the engine is opera ted above idle speed with no load on the propeller, the engine could RUNAWAY resulting in serious damage or destruction of the unit. CAUTION: Water must circulate through the lower unit to the engine any time the engine is run to prevent damage to the water pump in the lower unit. Just five seconds without water will damage the water pump. Start the powerhead and operate it at idle speed. Observe the vacuum gauge. The gauge should indicate no more than 17.7 em (7") of mercury. ACCUMIX (AUTOBLEND) SYSTEM DESCRIPTION The AccuMix (AutoBlend) oil injection system is designed to provide a fuel/oil ratio of 100/1 regardless of powerhead rpm. The AccuMix (Au toBlend) system is located en tirely inside the portable fuel tank. A 1-1/2 quart reservoir cannister contains enough oil for almost five tankfulls of fuel. An oil metering pump is located at the base of the cannister. This oil pump is activated by pulses from the fuel pump installed on the powerhead. The oil metering pump automatically blends fuel from the fuel pickup in the portable tank with oil in the reservoir cannister. The oil/fuel mixture passes through a built-in filter also located inside the cannister. A low-oil warning indicator activates a warning horn when the level of oil falls below one pint. If the operator sustains powerhead operation after the warning horn sounds, the fuel supply is automatically cut off to shutdown the powerhead. A visual low oil level indicator is located on the reservoir cannister cover. This indica tor is of the "glass eye" type, similar to those found on newer style automotive batteries. SPECIAL WORDS ON TROUBLESHOOTING Due to the inherent design of this oil injection system, very few individual parts can be repaired or replaced, if found to be defective. As an example: if the low oil level float is found to be defective, unfortunately, the entire system must be replaced. Therefore, no "troubleshooting" procedures are given, because no evaluating tests have been provided by the manufacturer. If any problem is encountered with the delivery of oil, follow the procedures outlined in the following paragraphs. The instructions deal mostly with cleaning out the system. If the problem persists, the only remedy is a new system. GENERAL MAINTENANCE Maintenace of this type oil injection system is limited to draining and flushing the oil reservoir cannister each season. To properly clean the cannister and the integral oil filter, it should be removed from the fuel tank and flushed with fresh gasoline or solven t. Procedures for reservoir cannister service will be found in the following paragraphs. When the reservoir cannister has been removed from the fuel tank, the fuel line pickup screen can also be serviced. Clean the vent screw and the area around the screw each time the fuel tank is filled. This vent screw MUST be FULLY OPEN to allow powerhead operation and to permit air to enter the tank and take the place of the consumed fuel. The vent screw and fuel tank cap cannot be serviced, other than cleaning. If defective for any reason, the assembly must be replaced as a unit. OIL RESERVOIR CANNISTER SERVICE Removal 1-Disconnect the electrical harness and the fuel line connec tor from the top of the cannister. Remove the eight slotted head retaining screws, securing the cover and cannister to the fuel tank. Observe the A top view of the AccuMix oil injection system. Eight screws secure the hcmdle cmd the cannister to the fuel tcmk. ACCUMI X 4-63 A cork gasket is used between the cannister flange cmd the fuel tank. Take care to align all holes when installing the cannister to avoid damage to this gasket. three additional washers under the tank handle bracket, when removing the handle. Lift out the cannister and cover together from the tank, taking care not to spill any oil remaining in the cannister. Remove and discard the gasket between the cannister flange and the tank. 2-Ease the cover from the cannister. The fuel tube must be disengaged from the cavity in the cover. Remove and discard the 0-ring between the cover and the cannister. Good Words Do not attempt to disassemble the oil pump at the cannister base. No replacement COVER The fuel tube MUSI' index with the cavity directly under the fuel joint cmd the eight holes in the o-ring MUSI' align with the cannister cmd cover holes prior to installing the cannister back into the fuel tank. 4-64 FL£L parts are available. If defective the pump must be replaced as an assembly. CLEANING AND INSPECTING Drain any oil from the cannister. Obtain a container of solvent and "dunk" the oil filter a couple of times. Take care not to alter the low oil level indica tor float. Use a shop towel moistened with solvent and wipe down the surfaces of the cover and the length of the low oil level indicator tube. Blow the cover assembly and fil ter dry with compressed air. Pour some solvent into the cannister to rinse any residue from the cannister walls. Make certain no debris obstructs the oil pump pickup or the low oil cutoff float mounted on the pump. Inspect and service the fuel line pickup screen, as necessary. Assembling 1-Secure the fuel pickup line into the clip at the base of the cannister. Place a new gasket on the fuel tank surface and lower the cannister into the tank. Align the cannister flange holes with the gasket holes. 2-Apply a light coat of OMC TripleGuard grease on both sides of the 0-ring, and then position the ring onto the cannister flange. Align the holes in the 0-ring with the flange holes. 3-Lower the cover over the cannister and make sure the fuel tube indexes with the cavity on the underside of the cover. 4-Position one washer at each of the three holes for the fuel tank handle bracket, and then hold the handle in place while these screws are started. Install the remaining screws fingertight. Tighten all eight screws alternately and evenly to a torque value of 10 in lb (l.lNm). Connect the electrical harness and the fuel connector to the fittings on top of the cannister. 5 IGNITION 5-l INTRODUCTION The less an outboard engine is operated, the more care it needs. Allowing an outboard engine to remain idle will do more harm than if it is used regularly. To maintain the engine in top shape and always ready for efficient operation at any time, the engine should be operating every 3 to 4 weeks throughout the year. The carburetion and ignition principles of two-cycle engine operation MUST be understood in order to perform a proper tuneup on an outboard motor. If you have any doubts concerning your understanding of two-cyle engine operation, it would be best to study the operation theory section in the first portion of Chapter 3, before tackling any work on the ignition system. Three ignition systems are used on the Johnson/Evinrude engines covered in this manual: the flywheel magneto system, the low tension flywheel magneto system, and two types of capacitor discharge (CD) magneto systems. The first sections of this chapter will be devoted to an explanation of the systems and their theory of operation. The latter sections will provide troubleshooting and repair instructions. For synchronizing procedures, see Section 5-9. An outboard engine should not be left idle for long View of the magneto installed on engines covered in periods of time. Lack of use or operation is its worst this manual. A one-cylinder engine will have only half enemy. the parts. 5-2 IGNITION 5-2 SPARK PLUG EVALUATION Removal: Remove the spark plug wires by pulling and twisting on only the molded cap. NEVER pull on the wire or the connection inside the cap may become separated or the boot damaged. Remove the spark plugs and keep them in order. TAKE CARE not to tilt the socket as you remove the plug or the insulator may be cracked. Examine: Line the plugs in order of removal and carefully examine them to determine the firing conditions in each cylinder. If the side electrode is bent down onto the center electrode, the piston is traveling too far upward in the cylinder and striking the spark plug. Such damage indicates the wrist pin or the rod bearing is worn excessively. In all cases, an engine overhaul is required to correct the condition. To verify the cause of the problem, turn the engine over by hand. As the piston moves to the full up position, push on the piston crown with a screwdriver inserted through the spark plug hole, and at the same time rock the flywheel back-and-forth. If any play in the piston is detected, the engine must be rebuilt. Correct Color: A proper firing plug should be dry and powdery. Hard deposits inside the shell indicate too much oil is being mixed with the fuel. The most important evidence is the light gray color of the porcelain, which is an indication this plug has been running at the correct temperature. This means the plug is one with the correct heat range and also that the air-fuel mixture is correct. This spark plug is foul from operating with an overrich condition, possibly an improper carburetor adiustment. Damaged spark plugs. Notice the broken electrode on the left plug. The broken part MUST be found and removed before returning the engine to service. Rich Mixture: A black, sooty condition on both the spark plug shell and the porcelain is caused by an excessively rich air-fuel mixture, both at low and high speeds. The rich mixture lowers the combustion temperature so the spark plug does not run hot enough to burn off the deposits. Deposits formed only on the shell is an indication the low-speed air-fuel mixture is too rich. At high speeds with the correct mixture, the temperature in the combustion chamber is high enough to burn off the deposits on the insulator. Too Cool: A dark insulator, with very few deposits, indicates the plug is running too cool. This condition can be caused by low compression or by using a spark plug of an incorrect heat range. If this condition shows on only one plug it is most usually caused by low compression in that cylinder. If all of the plugs have this appearance, then it is probably due to the plugs having a toolow heat range. This spark plug has been operating too-cool, because it is rated with a too-low heat range for the engine. Today, numerous type spark plugs are available for service. ALWAYS check with your local marine dealer to be sure you are purchasing the proper plug for the enpine being serviced. Fouled: A fouled spark plug may be caused by the wet oily deposits on the insulator shorting the high-tension current to ground inside the shell. The condition may also be caused by ignition problems which prevent a high-tension pulse being delivered to the spark plug. Carbon Deposits: Heavy carbon-like deposits are an indication of excessive oil in the fuel. This condition may be the result of poor oil grade, (automotive-type instead of a marine-type); improper oil-fuel mixture in the fuel tank; or by worn piston rings. Overheating: A dead white or gray insulator, which is generally blistered, is an indication of overheating and pre-ignition. The electrode gap wear rate will be more than normal and in the case of pre-ignition, will actually cause the electrodes to melt as Cut-a-way drawing showing major spark plug parts. POLARITY CHECK 5-3 shown in this illustration. Overheating and pre-ignition are usually caused by improper point gap adjustment; detonation from using too-low an octane rating fuel; an excessively lean air-fuel mixture; or problems in the cooling system. Electrode Wear: Electrode wear results in a wide gap and if the electrode becomes carbonized it will form a high-resistance path for the spark to jump across. Such a condition will cause the engine to misfire during acceleration. If all plugs are in this condition, it can cause an increase in fuel consumption and very poor performance during high-speed operation. The solution is to replace the spark plugs with a rating in the proper heat range and gapped to specification. Red rust-colored deposits on the entire firing end of a spark plug can be caused by water in the cylinder combustion chamber. This can be the first evidence of water entering the cylinders through the exhaust manifold because of scale accumulation. This condition MUST be corrected at the first opportunity. Refer to Chapter 3, Powerhead Service. 5-3 POLARITY CHECK Coil polarity is extremely important for proper battery ignition system operation. If a coil is connected with reverse polarity, the spark plugs may demand from 30 to 40 percent more voltage to fire. Under such demand conditions, in a very short time the coil would be unable to supply enough voltage to fire the plugs. Any one of the following three methods may be used to quickly determine coil polarity. 1-The polarity of the coil can be checked using an ordinary D.C. voltmeter. Connect the positive lead to a good ground. With the engine running, momentarily touch the negative lead to a spark plug terminal. 5-4 IGNITION The needle should swing upscale. If the needle swings downscale, the polarity is reversed. 2-If a voltmeter is not available, a pencil may be used in the following manner: Disconnect a spark plug wire and hold the metal connector at the end of the cable about 1/4" from the spark plug terminal. Now, insert an ordinary pencil tip between the terminal and the connector. Crank the engine with the ignition switch ON. If the spark feathers on the plug side and has a slight orange tinge, the polarity is correct. If the spark feathers on the cable connector side, the polarity is reversed. 3-The firing end of a used spark plug can give a clue to coil polarity. If the ground electrode is "c'ished", it may mean polarity is reversed. 5-4 WIRING HARNESS CRITICAL WORDS: These next two paragraphs may well be the most important words in this chapter. Misuse of the wiring harness is the most single cause of electrical problems with outboard power plants. The spark plug gap should always be checked before installing new or usee spark plugs. Drawing to illustrate a spark plug properly installed, center, and other plugs, left and right, improperly installed. This coil was destroyed because 12-volts was connected to the key switch. FLYWHEEL MAGNETO 5-5 A w1rmg harness is used between the key switch and the engine. This harness seldom contains wire of sufficient size to allow connecting accessories. Therefore, anytime a new accessory is installed, NEW wiring should be used between the battery and the accessory. A separate fuse panel MUST be installed on the dash. To connect the fuse panel, use one red and one black No. 10 gauge wire from the battery. If a small amount of 12-volt current should be accidently attached to the magneto system, the coil may be damaged or DESTROYED. Such a mistake in wiring can easily happen if the source for the 12-volt accessory is taken from the key switch. Therefore, again let it be said, NEVER connect accessories through the key switch. 5-5 FLYWHEEL MAGNETO IGNITION 1.25 hp 1986 & on 2 hp 1971-85 4 hp 1971-84* 6 hp 1971-76 9.5 hp 1971-73 18 hp 1971-73 20 hp 1971-72 25 hp 1971-72 40 hp 1971-73 *The 4 hp Deluxe, 1984 and on, has Type II, CD Flywheel Magneto Ignition. DESCRIPTION READ AND BELIEVE. A battery installed to crank the engine DOES NOT mean the engine is equipped with a battery-type ignition system. A magneto system uses the battery only to crank the engine. Once the engine is running, the battery has absolutely no effect on engine operation. Therefcre, if the battery is low and fails to crank the engine properly for starting, the engine may be cranked manually, started, and operated. Under these conditions, the key switch must be turned to the ON position or the engine will not start by hand cranking. A magneto system is a self-contained unit. The unit does not require assistance from an outside source for starting or continued operation. Therefore, as previously mentioned, if the battery is dead, the engine may be cranked manually and the engine started. MAGNET HIGH TENS ION KEY .\t SPARK PLUG BREAKER PO I NTS Schematic diagram of a magneto ignition system. 5-6 IGNITION The flywheel-type magneto unit consists of an armature plate and a permanent magnet built into the flywheel. The ignition coil, condenser and breaker points are mounted <;:m the armature plate. As the pole pieces of the magnet pass over the heels of the coil, a magnetic field is built up about the coil, causing a current to flow through the primary winding. Now, at the proper time, the breaker points are separated by action of a cam, and the primary circuit is broken. When the circuit is broken, the flow of primary current stops and causes the magnetic field about the coil to break down instantly. At this precise moment, an electrical current of extremely high voltage is induced in the fine secondary windings of the coil. This high voltage is conducted to the spark plug where it jumps the gap between the points of the plug to ignite the compressed charge of air-fuel mixture in the cylinder. TROUBLESHOOTING Always attempt to proceed with the troubleshooting in an orderly manner. The shotgun approach will only result in wasted time, incorrect diagnosis, replacement of unnecessary parts, and frustration. Begin the ignition system troubleshooting with the spark plug/s and continue through the system until the source of trouble is located. Remember, a magneto system is a selfcontained unit. Therefore, if the engine has a key switch and wire harness, remove them from the engine and then make a test for Overall view of the magneto showing major parts, coils, points, condenser and armature plate. DIAPHRAGM TO MAGNETO VENT Sche matic diagram of a vacuum cutout switch used on early model small horsepower engine. This illustration depicts the position of the diaphragm in relation to the ground contact when operating at normal manifold pressure. Spring omitted for clarity. spark. If a good spark is obtained with these two items disconnected, but no spark is available at the plug when they are connected, then the trouble is in the harness or the key switch. If a test is made for spark at the plug with the harness and switch connected, check to be sure the key switch is turned to the ON position. Vacuum Cutout Switch On some 40 hp engine models, a cutout vacuum switch is installed. This switch is connected to one of the cylinders in the CLOSED CONTACT TO MAGNETO VENT Schematic diagram of the cutout switch to depict the diaphragm making contact with the ground. This condition results from abnormally high manifold suction on the instant of rapidly throttling down from high to slow idle speed with the engine in neutral. Sprinp not shown for clarity. ignition system. The switch is actuated by vacuum from the cylinder. When a high vacuum pull is exerted against the switch, during engine operation in gear without the lower unit in the water, the switch is closed and the engine is shut down. This feature is a safeguard against the engine "running away" while operating with a no-load condition on the propeller. A two-cycle engine will continue to increase rpm under a noload condition and attempts to shut it down will fail, resulting in serious damage or destruction of the unit. The vacuum switch also serves as a safety feature when the boat is operating in the GASKET HOUNTING BRACKET TROUBLESHOOTING 5-7 water. If the propelJer is released from the shaft, because of an accident (striking an underwater object, whatever), the engine would then be operating under a no-load condition. The vacuum switch will shut down the engine and prevent extensive damage, resulting from a "runaway" condition. This cutout switch arrangement was installed on the 40 hp engines, 1971-76. Therefore, if spark is not present at the spark plug, disconnect the wires from the vacuum switch and again test for spark at the spark plug. If spark is present with the vacuum switch disconnected, the switch is defective and must be replaced. IIAGNETO LEAD /NUT WASHER \ _,_.- WASHER /® / / GROUND WIRE Exploded drawing of a "runaway'' cutout switch installed on most late-model powerheads. 5-8 IGNITION WIRING HARNESS CRITICAL WORDS: These next two paragraphs may well be the most important words in this chapter. Misuse of the wiring harness is· the most single cause of electri.:. cal problems with outboard power plants. A wiring harness is used between the key switch and the engine. This harness seldom contains wire of sufficient size to allow connecting accessories. Therefore, anytime a new accessory is installed, NEW wiring should be used between the battery and the accessory. A separate fuse panel MUST be installed on the dash. To connect the fuse panel, use one red and one black No. 10 gauge wires from the battery. If a A coil DESTROYED when 12-volts was connected small amount of 12-volt current should be into the magneto wiring system. Mechanics report in 85% of the cases, the da mage occurs when an accessory accidently attached to the magneto system, is connected through the key switch. the coil will be damaged or DESTROYED. Such a mistake in wiring can easily happen grounded. For this reason, an automotiveif the source for the 12-volt accessory is type switch MUST NEVER be used, because taken from the key switch. Therefore, the circuit would be opened and closed in again let it be said, NEVER connect accesreverse, and if 12-volts should reach the sories throu..h the key switch. coil, the coil will be DESTROYED. Key Switch Spark Plugs A magneto key switch operates in RE-1-Check the plug wires to be sure they VERSE of any other type key switch. When are properly connected. Check the entire the key is moved to the OFF position, the length of the wire/s from the plug/s to the circuit is CLOSED between the magneto and magneto under the armature plate. If the ground. In some cases, when the key is wire is to be removed from the spark plug, turned to the OFF position the points are ALWAYS use a pulling and twisting motion KEY SWITCH BOW PANEL STERN LI GHT LIGHT BATTERY -x"i SW I TCH WIRING HARN ES S BOX Functional diagram to illustrate proper hookup of accessories through a junction box. If a junction is not installed on WIR lNG HARt..ESS SWITCH BOW LIGHT SWITCH the boat, connect accessories directly to the battery. NEVER connect accessories through the key switch. TROUBLESHOOTING 5-9 as a precaution against damaging the connection. 2-Attempt to remove the spark plug/s by hand. This is a rough test to determine if the plug is tightened properly. You should not be able to remove the plug without using the proper socket size tool. Remove the spark plug/s and keep them in order. Examine each plug and evaluate its condition as described in Section 5-2. If the spark plugs have been removed and the problem cannot be determined, but the plug appears to be in satisfactory condition, electrodes, etc., then replace the plugs in the spark plug openings. A conclusive spark plug test should always be performed with the spark plugs installed. A plug may indicate satisfactory spark when it is removed and tested but under a compression condition may fail. An example would be the possibility of a person being able to jump a given distance on the ground, but if a strong wind is blowing, his distance may be reduced by half. The same is true with the spark plug. Under good compression in the cylinder, the spark may be too weak to ignite the fuel properly. Therefore, to test the spark plug under compression, replace it in the engine and tighten it to the proper torque value. Another reason for testing for spark with the plugs installed is to duplicate actual operat- PARK PLUG LEAD ing conditions regarding flywheel speed. If the flywheel is rotated with the pull cordwith the plugs removed, the flywheel will rotate much faster because of the no-compression condition in the cylinder, giving the FALSE indication of satisfactory spark. 5-10 IGNITION 3-Use a spark tester and check for spark at each cylinder. If a spark tester is not available, hold the plug wire about 1/4inch from the engine. Turn the flywheel with a pull starter or electrical starter and check for spark. A strong spark over a wide gap must be observed when testing in this manner, because under compression a strong spark is necessary in order to ignite the airfuel mixture in the cylinder. This means it is possible to think you have a strong spark, when in reality the spark will be too weak when the plug is installed. If there is no spark, or if the spark is weak, the trouble is most likely under the flywheel in the magneto. ONE MORE WORD: Each cylinder has its own ignition system in a flywheel-type ignition system. This means if a strong spark is observed on any one cylinder and not at another, only the weak system is at fault. However, it is always a good idea to check and service all systems while the flywheel is removed. Compression A compression check is extremely important, because an engine with low or uneven compression between cylinders CAN NOT be tuned to operate satisfactorily. Therefore, it is essential that any compression problem be corrected before proceeding with the tune-up procedure. If the powerhead shows any indication of overheating, such as discolored or scorched paint, especially in the area of the top (No. 1) cylinder, inspect the cylinders visually thru the transfer ports for possible scoring. A more thorough inspection can be made if the head is removed. It is possible for a cylinder with satisfactory compression to be scored slightly. Also, check the water pump. The overheating condition may be caused by a faulty water pump. An cverheating condition may also be caused by running the engine out of the water. For unknown reasons, many operators have formed a bad habit of running a small engine without the lower unit being submerged. Such a practice will result in an overheated condition in a matter of seconds. It is interesting to note, the same operator would never opera te or allow anyone else to run a large horsepower engine without water circulating through the lower unit for cooling. Bear in mind, the laws governing operation anc:i damage to a large unit ALL apply equally as well to the sma!I engine. The preferred method of checking the cylinder walls and rings is to pull the head and make an inspection. This method will also reveal the piston condition in each cylinder. Checking the rings and cylinder walls throuqh the opening on the exhaust side of the engine to be sure the walls are not scored and the rinas are not stuck in the piston (fail to expand properly). .. Checking Compression 4-Remove the spark plug wires. ALWAYS grasp the molded cap and pull it loose with a twisting motion to prevent damage to the connection. Remove the spark plugs and keep them in ORDER by cylinder for evaluation later. Ground the spark plug leads to the engine to render the ignition system inoperative while performing the compression check. Insert a compression gauge into the No. 1 (top), spark plug opening. Crank the engine with the starter, or pull on the starter cord, through at least 4 complete piston strokes with the throttle at the wideopen position, or until the highest possible reading is observed on the gauge. Record the reading. Repeat the test and record the compression for each cylinder. A variation between cylinders is far more important than the actual readings. A variation of more than 5 psi between cylinders indicates the lower compression cylinder may be defective. The problem may be worn, broken, or sticking piston rings, scored pistons or worn cyl.in.. ders. These problems may only be determined after the head has been removed. Removing the head on an outboard engine is · not that big a deal, and may save many hours of frustration and the cost of purchasing unnecessary parts to correct a faulty condition. Condenser In simple terms, a condenser is composed TROUBLESHOOTING 5-11 ALTERNATE LAYERS OF INSULATION (WAXED PAPER) ALTERNATE LAYERS OF FOIL (TIN OR ALUMINUM) FOIL INSULATION Rough sketch to illustrate how the waxed paper, aluminum foil, and insulation are rolled in a typical condenser. one on top of the other, but separated by a sheet of insulating material such as waxed paper, etc. The sheets are rolled into a cylinder to conserve space and then inserted into a metal case for protection and to permit easy assembly. The purpose of the condenser is to absorb or store the secondary current built up in the primary winding at the instant the breaker points are separated. By absorbing or storing this current, the condenser pre..:: vents excessive arcing and the useful life of the breaker points is extended. The condenser also gives added force to the charge produced in the secondary winding as the condenser discharges. Modern condensers seldom cause problems, therefore, it is not necessary to install a new one each time the points are replaced. However, if the points show evidence of arcing, the condenser may be at fault and should be replaced. A faulty condenser may not be detected without the use of special of two sheets of tin or aluminum foil laid test equipm ent. The modest cost of a new condenser justifies its purchase and installation to eliminate this item as a source of trouble. Proper hookup to test a condenser. 5-12 IGNITION Worn and corroded breaker points unfit for further service. Breaker Points The breaker points in an outboard motor are an extremely important part of the ignition system. A set of points may appear to be in good condition, but they may be the source of hard starting, misfiring, or poor engine performance. The rules and knowledge gained from association with 4-cycle engines does not necessarily apply to a 2cycle engine. The points should be replaced every 100 hours of operation or at least once a year. REMEMBER.. the less an outboard engine is operated, the more care it needs. Allowing an outboard engine to remain idle will do more harm than if it is used regularly. A breaker point set consists of two points. One is attached to a stationary PROPER LATERAL ALI GNMENT Drawing to illustrate proper point alignment, bottom set, compared with exaggerated misalignment of the other two. bracket and does not move. The other point is attached to a moveable mount. A spring is used to keep the points in contact with each other, except when they are separated by the action of a cam built into the flywheel or machined on the crankshaft. Both points are constructed with a steel base and a tungsten cap fused to the base. To properly diagnose magneto (spark) problems, the theory of electricity flow must be understood. The flow of electricity through a wire may be compared with the flow of water through a pipe. Consider the voltage in the wire as the water pressure in the pipe and the amperes as the volume of water. Now, if the water pipe is broken, the water does not reach the end of the pipe. In a similar manner if the wire is broken the flow of electricity is broken. If the pipe springs a leak, the amount of water reaching the end of the pipe is reduced. Same with the wire. If the installation is defective or the wire becomes grounded, the amount of electricity (amperes) reaching the end of the wire is reduced. Check the wiring carefully, inspect the points closely and adjust them accurately. The point setting for ALL engines covered in this section is 0.020". An added item of useful information simplifying purchase of new points is that ALL point sets for the engines coverec1 ir this section have the same part number, No. 580 148. .016 FEELER GAUGE Drawing to depict how a 0.016" feeler gauge may be inserted between a badly worn set of points and the actual opening is 0.021". The point set must be in good condition to obtain an accurate adjustment. SERVICING FLYWHEEL MAGNETO 5-1 3 SERVICING FLYWHEEL MAGNETO IGNITION SYSTEM General Information Magnetos installed on outboard engines will usually operate over extremely long periods of time without requiring adjustment or repair. However, if ignition system problems are encountered, and the usual corrective actions such as replacement of spark plugs does not correct the problem, the magneto output should be checked to determine if the unit is functioning properly. Magneto overhaul procedures may differ slightly on various outboard models, but the battery terminals, if a battery is used to crank the engine. If a hand starter is installed, remove the attaching hardware from the legs of the starter assembly and lift the starter free. 2-On hand started models, a round ratchet plate is attached to the flywheel to allow the hand starter to engage in the ratchet and thus turn the flywheel. This plate must be removed before the flywheel nut is removed. 3-Remove the nut securing the flywheel to the crankshaft. It may be necessary to use some type of flywheel strap to prevent the flywheel from turning as the nut is loosened. following general basic instructions will apply to all Johnson/Evinrude hi..h speed flywheel- type magnetos. REMOVAL 1-Remove the hood or enough of the engine cover to expose the flywheel. Disconnect the battery connections from the 4-Install the proper flywheel puller using the same screw holes in the flywheel 5-14 IGNITION that are used to secure the ratchet plate removed in Step 2. NEVER attempt to use a puller which pulls on the outside edge of the flywheel or the flywheel may be damaged. After the puller is installed, tighten the center screw onto the end of the crankshaft. Continue tightening the screw until the flywheel is released from the crankshaft. Remove the flywheel. DO NOT strike the puller center bolt with a hammer in an attempt to dislodge the flywheel. Such action could seriously damage the lower seal and/or lower bearing. 5-STOP, and carefully observe the magneto and associated wiring layout. Study how the magneto is assembled. TAKE TIME to make notes on the wire routing. Observe how the heels of the laminated -core, with the coil attached, is flush with the boss on the armature plate. These items must be replaced in their proper positions. You may elect to follow the practice of many professional mechanics by taking a series of photoll(raphs of the engine with the flywheel removed: one from the top, and a couple from the sides showing the wiring and arrangement of parts. Breaker Points/Condenser Service The armature plate does not have to be removed to service the magneto. If it is necessary to remove the plate for other service work, such as to replace the coil or This particular engine differs from the text procedures because a washer is installed under the flywheel nut. to replace the top seal, see Step 12. For simplicity and clarity, the following procedures and accompanying illustrations cover a one-cylinder ignition system. If larger than one-cylinder Is being serviced, repeat the procedures for each coil and breaker point assembly. 6-Remove the screw attaching the wires from the coil and condenser to one set of points. On engines equipped with a key switch, "kill" button, or "runaway" switch, a ground wire is also connected to this screw. 7-Using a pair of needle-nose pliers remove the wire clip from the post protrud ing through the center of the points. 8-Again, with the needle-nose pliers, rP.move the flat retainer holc'ing the set cf points together. After the flywheel has been removed it should be placed on the bench with the mapnets facing upward. This position will help prevent small particles from becoming attached to the magnets. SERVICING FLYWHEEL MAGNETO 5-15 9-Lift the moveable side of the points free of the other half of the set. 10-Remove the hold-down screw securing the non-moveable half of the point set to the armature plate. 11-Remove the hold down screw securing the condenser to the armature plate. Observe how the condenser sets into a recess in the armature plate. Repeat the procedure for the other set of points. 5-16 IGNITION Armature Plate Removal First, These Words: It is not necessary to remove the armature plate unless the top seal or the coil is to be replaced. 12-Disconnect the advance arm connecting the armature plate with the power shaft on the side of the engine. Next, remove the wires connecting the underside of the armature plate with the "kill" switch. If a "kill" switch is not installed, these wires are connected to the wiring harness plug. The wires of most units have a quick-disconnect fi tting. Remove the wires from the vacuum (runaway) switch, if one is installed. 13-Observe the four screws in a square pattern through the armature plate. Two of these screws pass through the lamina ted core and the armature plate into the po.,xrerhead retainer. The other two pass just through the plate. Loosen these four screws. After the screws are loose, lift the ar rna ture pia te up the crankshaft and clear of the engine. If any oil is present on top of the armature pia te, or on the points, the top seal MUST be replaced. Top Seal Replacement Replace ment of the top seal on a Johnson/ Evinrude engine is NOT a difficult task, with the proper tools: a seal remover and seal installer. NEVER attempt to remove the seal with screwdrivers, punch, pick, or other similar tool. Such action will most likely damage the collars in the powerhead. Obtain OMC Seal Remover P/N 387780. A 1-1/8" open end wrench is needed to hold the remover portion of the tool, while a 3/8" open end wrench is used on the top bolt. 14-To remove the seal, first, work the point cam up and free of the driveshaft. Next, remove the Woodruff key from the crankshaft. A pair of side-cutters is a handy tool for this job. Grasp the Woodruff key with the side-cutters and use the leverage of the pliers against the crankshaft to remove the key. 15-Work the special tool into the seal. Observe how the special tool is tapered ancl has threads. Continue working and turning the tool until it has a firm grip on the inside of the seal. Now, tighten the center screw of the puller against the end of the crankshaft and the seal will begin to lift from the collars. Continue turning this center screw until the seal can be raised manually from the crankshaft. SERVICING FLYWHEEL MAGNETO 5-17 16-To install the new seal: Coat the inside diameter of the seal with a thin layer of oil. Apply 0!\/lC sealer to the outside diameter of the seal. Slide the seal down the crankshaft and start it into the recess of the powerhead. Use the special tool and work the seal completely into place in the recess. 17-Install the Woodruff key into the crankshaft. On some models, a pin was used to locate the cam for the points. If the pin was used, install it at this time. Oberve the difference to the sides of the cam. On almost all cams, the word TOP is stamped on one side. Also, on some cams, the groove does not go all the way through. Therefore, it is very difficult to install the cam incorrectly, with the wrong side up. Slide the cam down the crankshaft with the word TOP facing upward. Continue working the cam down the crankshaft until it is in place over the Woodruff key or pin. If the coil is not to be removed, proceed directly to Step 7. To remove the coil, perform the procedures in the following section. Coil Removal from the Armature Plate The armature plate must be removed as described earlier in this section, Step 12 and Step 13. Notice how the coil has a laminated core. The coil cannot be separatecl, that is, the laminations from the core. 18-Turn the armature plate over and notice how the high-tension leads are installed on the plate in a recess. The routing of the wires is misleading. The wire to the No. 1 spark plug is NOT connected to the No. 1 coil as might be expected. 19-Remove the three screws attaching the coils to the armature plate. 5-18 IGNITION r-- l 1 FLYWHEEL :1 'i ..-----NUT iI __ I .. COIL POINT LEAD · . Exploded drawr·ng o f otypwal magneto system • only one coil and set o f pomts are sho wn. SERVICING FLYWHEEL MAGNETO 5-19 20-Hold the armature plate and separate the coils from the plate. As the coil is separated from the plate, observe the hightension lead to the spark plug inside the coil. Work the small boot, if used, and the high-tension lead from the coil. CLEANING AND INSPECTING Inspect the flywheel for cracks or other damage, especially around the inside of the center hub. Check to be sure metal parts have not become attached to the magnets. Verify each magnet has good magnetism by using a screwdriver or other tool. Thoroughly clean the inside taper of the flywheel and the taper on the crankshaft to prevent the flywheel from "walking" on the crankshaft while the engine is running. Check the top seal around the crankshaft to be sure no oil has been leaking onto the armature plate. If there is ANY evidence the seal has been leaking, it MUST be replaced, as outlined earlier in this section. A coil destroyed when the side blew out. This damaae was caused when 12-volts was connected to the magn..to circuit at the key switch. Test the armature plate to verify it is not loose. Attempt to lift each side of the plate. There should be little or no evidence of movement. Clean the surface of the armature plate where the points and condenser attach. Install a new condenser into the recess and secure it with the hold-down screw. A broken crankshaft and cracked flywheel damaged when the engine was operated at a high rpm with a flush attachment and garden hose connected to the lower unit. Cracks in the flywheel hub caused by metal fatigue due to flywheel construction and the inspection hole. A coil burned where the high-tension lead enters the This hole is no longer incorporated in late-model fly coil on the bottom side. Arcing caused the damage. wheels. 5-20 IGNITION ASSEMBLING Coil to Armature Plate 1-To install a new coil, first turn the armature plate over, and loosen the spark plug lead wires, and push them through the armature plate. Now, work the leads into the coil. 2-After the leads are into the coil, work the small boot up onto the coil. Apply a coating of rubber seal material underneath the boot, if a boot is used. 3-Start the three screws through the laminated core into the armature plate, but DO NOT tighten them. If the engine being serviced has a second coil, install the other coil in the same manner. 4-Check to be sure the spark plug (hightension) leads are properly positioned in the coil and are securely attached to the bottom side of the armature plate. 5-To adjust the coils: A special ring tool is required that fits down over the armature plate. This tool will properly locate the coil in relation to the flywheel. Install this special tool over the armature plate. Push outward on the coil and secure the two outer screws. SERVICING FLYWHEEL MAGNETO 5-2 1 6-If a special ring tool is not available, and in an emergency, hold a straight edge against the boss on the armature plate and bring the heel of the laminated core out square against the edge of the boss on the armature plate. The ground wire for the coil should be attached under the head of the top screw passing through the laminated core. Wick Replacement 7-The wick, mounted in a bracket under the coil, can be replaced without removing the armature plate. The wick SHOULD be replaced each and every time the breaker points are replaced. To replace the wick, simply loosen all three coil retaining screws and remove the one screw through the wick holder. Lift the coil slightly and remove the wick and wick holder. Slide the new wick into the holder; install the holder and wick under the coil; and secure it in place with the retaining screw. Adjust the coil as described earlier in this section, Steps 5 and ·· 6, and tighten the three screws. Armature Plate Installation 8-Slide the armature plate down over the crankshaft and onto the engine. Align the screw holes in the armature plate with the holes in the powerhead retainer. After the armature plate is in place, install and tighten the two screws securing the armature plate to the retainer. Now, take up on the three screws through the laminated core closest to the crankshaft. Tighten the screws securely. Attach the advance arm from the magneto to the tower shaft arm. GOOD WORDS All engines covered in this section use the same set of points (Part No. 580148). The points MUST be assembled as they are installed. One side of each point set has the base and is non-moveable. The other side of the set has a moveable arm. A small wire clip and a flat retainer are included in each point set package. 9-Hold the base side of the points and the flat retainer. Notice how the base has a bar at right angle to the points. Observe the hole in the bar. Observe the flat retainer. Notice that one side has a slight indentation. When the points are installed, this indentation will slip into the hole in the base bar. 5-22 IGNITION Point Set 10-Install the condensers and secure them in place with their hold-down screws. 11-Hold the base side of the points and slide it down over the anchor pin onto the armature plate. Install the wavy washer and hold-down screw to secure the point base to the armature plate. Tifi:hten the hold-clown screw securely. 12-Hold the moveable arm and slide the points down over post, and at the same time, hold back on the points and work the spring arm to the inside of the post of the base points. Continue to work the points on down into the base. 13-Observe the points. The points should be together and the spring part of the moveable arm on the inside of the flat post. 14-Install the flat retainer onto the flat bar of the base points. Check to be sure the flat spring from the other side of the points is on the inside of the retainer. Push the retainer inward until the indentation slips into the hole in the base. The retainer MUST be horizontal with the armature plate. 15-Install the wire clip into the groove of the post. Repeat Steps No. 10 thru 15 for the second set of points. should be required, CAREFULLY bend the insulated part of the point set. gauge will always give a more accurate adjustm ent than a feeler gauge. Work the gauge between the points and, at the same time, turn the eccentric on the armature plate until the proper adjustment (0. 020") is obtained. Rotate the crankshaft a complete should be required, CAREFULLY bend the insulated part of the point set. gauge will always give a more accurate adjustm ent than a feeler gauge. Work the gauge between the points and, at the same time, turn the eccentric on the armature plate until the proper adjustment (0. 020") is obtained. Rotate the crankshaft a complete CRITICAL WORDS As the coil, condenser, and "kill" switch wire are being attached to the point set, take the following precautions and adjustments: a-The wire between the coil and the points should be tucked back under the coil and as far away from the crankshaft as possible. b-The condenser wire leaving the top of the condenser and connected to the point set, should be bent downward to prevent the flywheel from making contact with the wire. A countless number of installations have been made only to have the flywheel rub against the condenser wire and cause failure of the ignition system. c-Check to be sure all wires connected to the point set are bent downward toward the armature plate. The wires MUST NOT touch the plate. If any of the wires make contact with the armature plate, the ignition sys tem will be grounded and the engine will fail to start. 16-Connect the wire leads to the set of points, with the attaching screw. Repea t all of these Critical Words for the second set of points. GOOD WORDS The point spring tension is prede termined at the fac tory and does not require adjustment. Once the point set is properly installed, all should be well. In most cases, breaker contact and alignment will not be necessary. If a slight alignment adjustment SERVICING FLYWHEEL MAGNETO 5-23 Before setting the breaker point gap, the points must be properly aligned (top). ALWAYS bend the stationary point, NEVER the breaker lever. Attempting to adjust an old worn set of points is not practical because oxidation and pitting of the points will always give a false reading. Point Adjustment 17-Install the flywheel nut onto the end of the crankshaft. Now, turn the crankshaft clockwise and at the same time observe the cam on the crankshaft. Continue turning the crankshaft until the rubbing block of the point set is at the high point of the cam. At this position, use a wire gauge or feeler gauge and set the points at 0.020" for all models covered in thi.s section. A wire 5-24 IGNITION revolution and again check the gap adjustment. After the crankshaft has been turned and the points are on the high point of the cam check to be sure the hold-down screw is ti..ht against the base. There is enough clearance to allow the eccentric on the base points to turn. If the hold-down screw is tightened AFTER the point adjust..ent has been made, it is very likely the adJustment will be changed. Follow the same pr?cedure and adjust the other set of pomts. Remove the nut from the crankshaft. Flywheel Installation 18-Check to be sure the flywheel magnets are free of any metal parts. 19-Place the key in the crankshaft keyway. Check to be sure the inside taper of the flywheel and the taper on the crankshaft are clean of dirt or oil, to prevent the flywheel from "walking" on the crankshaft while the engine is operating. Slide the flywheel down over the crankshaft with the keyway in the flywheel aligned with the key on the crankshaft. 20-Rotate the flywheel clockwise and check to be sure the flywheel does not contact any part of the magneto or the wiring. 21-Place the ratchet for the starter on top of the flywheel and install the three 7/16" screws. On some model engines, a plate retainer covers these screws. 22-Thread the flywheel nut onto the crankshaft and tighten it to the torque value given in the Appendix. - 23-After the ratchet and flywheel nut have been .installed, install the hand starter over the flywheel, if one is used. Check to be sure the ratchet engages the flywheel properly. This particular engine differs from the text procedures because a washer is installed under the flywheel nut. 24-Set the gap on each spark plug at 0.030". 25-Install the spark plugs and tighten them to the torque value of 210-246 in lbs. Connect the battery leads to the battery terminals, if a battery is used with a starter motor to crank the powerhead. To synchronize the powcrhead, proceed directly to Section 5-9. HAND /STARTER SERVICING FLYWHEEL MAGNETO 5-25 A good grade of OMC approved oil should always be used. Operating the engine in a test tank to verify proper water circulation and engine performance. 5-26 IGNITION 5-6 LOW TENSION FLYWHEEL MAGNETO IGNITION SYSTEM 9.9 hp 1974-76 15 hp 1974-76 18 hp 1973 20 hp 1973 25 hp 1973-76 35 hp 1976 40 hp 1974-76 40 hp Comm. 1981-83* *Some 40 hp Comm., 1983 models have the Type II, CD Flywheel Magneto Ignition. DESCRIPTION READ AND BELIEVE. A battery installed to crank the engine DOES NOT mean the engine is equipped with a battery-type ignition system. A low tension magneto system uses the battery only to crank the engine. Once the engine is running, the battery has absolutely no effect on engine operation. Therefore, if the battery is low and fails to crank the engine properly for starting, the engine may be cranked manually, started, and operated. Under these conditions, the key switch must be turned to the ON position or the engine will not start by hand cranking. A low tension magneto system is a selfcontained unit. The unit does not require assistance from an outside source for starting or continued operation. Therefore, as previously mentioned, if the battery is dead, the engine may be cranked manually and the engine started. The low tension magneto of this system Cut-a-way view of a coil showing the primary and secondary windings. is essentially a self-contained electrical generating unit. The low tension magneto consists of an armature plate with one driver coil and lamination assembly, two condensers, and two breaker assemblies. Two permanent magnets are cast into the flywheel on manual start engines. Four magnets are used on the electric start models. Overall view of a low-tension ignition system showLow- tension ignition system showing the driver coil, ing the driver coil and two charging coils. point set and condenser. the ignition system troubleshootthe spark plug/s and continue through the system until the source of trouble is located. the ignition system troubleshootthe spark plug/s and continue through the system until the source of trouble is located. Individual separate coils are installed for each cylinder. These coils are installed on the side of the engine, not under the flywheel as in other systems. Each coil may be considered as two coils. One, called the primary _coil, consists of a relatively few turns of heavy gauge copper wire. The other coil, called the secondary, consists of many turns of fine gauge wire. Insulation separates the two coils. One end of primary coil is grounded and the other end is connected to the stationary breaker point. One end of the secondary coil is also grounded and the other end is connected to the spark plug. The movable side of the breaker point set is grounded to the armature plate. The condenser can be likened to a stor tank. The condenser consists of thin of metal foil separated by insulation. The sheet and insulation are rolled to save space. One sheet of the foil is grounded to the case and the other sheet is connected to the stationary side of the breaker point set. THEORY OF OPERATION On a manual start unit, consider one of the magnets cast into the flywheel as No. 1. Consider the opposite magnet 180 ° from the first as No. 2. Consider one of the breaker point sets as No. 1 and the other as No. 2. Consider the matching ignition coil as No. 1 and the other as No. 2. Now, as the flywheel rotates, No. 1 magnet passes the driver coil inducing current flow from the driver coil through point set No. 1 (closed) across the armature plate up through the No. 2 set of points (also closed), and then to the other side of the driver coil. LOW TENSION MAGNETO 5-27 The cam opens the No. 1 point set and the voltage rises rapidly across the primary of ignition coil No. 1. The condenser in the primary absorbs the current which would otherwise arc across the No. 1 set of open points. The ignition coil, being a transformer, steps up the voltage into the secondary. The current moves on to the No. 1 spark plug and No. 1 cylinder fires, reference illustration "A". 0 The No. 2 magnet, 180 away and of opposite polarity, passes the driver coil, inducing current flow from the driver coil through the No. 2 point set (closed) across the armature plate up through the No. 1 point set (also closed) and then to the other side of the driver coil. The cam now opens the No. 2 point set , and the voltage rises rapidly across the primary of the No. 2 ignition coil. The condenser in the primary absorbs the current which would otherwise arc across the No. 2 point set opening. The ignition coil steps up the voltage. The current moves to the No. 2 spark plug and No. 2 cylinder fires, reference illustration "B". TROUBLESHOOTING Always attempt to proceed with the troubleshooting in an orderly manner. The shotgun approach will only result in wasted time, incorrect diagnosis, replacement of unnecessary parts, and frustration. ing 5-28 IGNITION Remember, a low tension magneto system is a self-contained unit. Therefore, if the engine has a key switch and wire harness, remove them from the engine and then make a test for spark. If a good spark is obtained with these two items disconnected, but no spark is available at the plug when they are connected, then the trouble is in the harness or the key switch. If a test is made for spark at the plug with the harness and switch connected, check to be sure the key switch is turned to the ON position. CRITICAL WORDS A very high voltage exists with this type of ignition system. NEVER physically touch a spark plug while attempting to determine if current exists or if there is spark at the plug. The voltage generated in the system will give a person one helluva JOLT. Key Switdl A low tension magneto key switch operates in REVERSE of any other type key switch. When the key is moved to the OFF position, the circuit is CLOSED between the low tension magneto and ground. In some cases, when the key is turned to the OFF position the points are grounded. For this reason, an automotive-type switch MUST NEVER be used, because the circuit would be opened and closed in reverse, and if 12volts should reach the coil, the coil will be DESTROYED. Spark Plugs 1-Check the plug wires to be sure they are properly connected. Check the entire length of the wire/s from the plug/s to the coil mounted on the side of the engine. If the wire is to bE> removed from the spark plug, ALWAYS use a pulling and twisting motion as a precaution against damaging the connection. 2-Attempt to remove the spark plug/s by hand. This is a rough test to determine if the plug is tightened properly. You should not be able to remove the plug without using the proper socket size tool. Remove the spark plug/s and keep them in order. Examine each plug and evaluate its condition as described in Section 5-2. If the spark plugs have been removed and the problem cannot be determined, but the plug appears to be in satisfactory condition, electrodes, etc., then replace the plugs in the spark plug openings. A conclusive spark plug test should always be performed with the spark plugs installed. A plug may indicate satisfactory spark when it is removed and tested, but under a compression condition may fail. An example would be the possibility of a person being able to jump a given distance on the ground, but if a strong wind is blowing, his distance may be reduced by half. The same is true with the spark plug. Under )O';ood compression in the cylinder, the spark may be too weak to ignite the fuel properly. Therefore, to test the spark plug under compression, replace it in the engine and tighten it to the proper torque value. Another reason for testing for spark with the plugs installed is to duplicate actual operating conditions regarding flywheel speed. If the flywheel is rotated with the pull C'Xd with the plugs removed, the flywheel will rotate much faster because of the no-compression condition in the cylinder, giving the FALSE indication of satisfactory spark. A spark tester, reference illustration "C•, capable of testing for spark while cranking and also while the engine is operating, can be purchased from almost any good automotive supply store. This type tester uses a small neon bulb which flashes under firing voltage. 3-Use a spark tester and check for spark at each cylinder. If a spark tester is not available, hold the plug wire about 1/14-inch from the engine. Turn the flywheel with a pull starter or electrical starter and check for spark. A strong spark over a wide gap must be observed when testing in this manner, because under compression a strong spark is necessary in order to ignite the airfuel mixture in the cylinder. This means it is possible to think you have a strong spark, when in reality the spark will be too weak when the plug is installed. If there is no spark, or if the spark is weak, the trouble is most likely under the flywheel in the magneto. LOW TENSION MAGNETO 5-29 ONE MORE WORD: Each cylinder has its own ignition system in a flywheel-type ignition system. This means if a strong spark is observed on any one cylinder and not at another, only the weak system is at fault. A single driver coil is used for both cylinders. Therefore, it is always a good idea to check and service all systems while the flywheel is removed. Coil Testing The following steps outline procedures to be followed to test the driver coil, point set, and condenser. Proper testing is almost impossible without special equipment. In a marine shop, an S-80 or M-80 tester may be used. If the necessary test equipment is unavailable to the outboard owner, the driver coil may be removed and taken to a marine shop for testing. 4-Disconnect the blue wire from the No. l ignition co i1 (the top coil). Connect one lead of the neon light to the blue wire coming up from under the armature plate. Connect the other test lead to a good ground en the engine. Crank the engine through several revolutions, and at the same time observe the light. If the service work is being performed in the out-of-doors, it may be necessary to provide some type of shade in order to observe the light with confidence. A steady bright light indicates satisfactory output from under the flywheel, inoperative while performing the compression check. inoperative while performing the compression check. 5-30 IGNITION and the ignition problem may very well be the No. 1 coil i.s unfit for service. A dim light indicates an open condenser. No light requires a check of the driver coil. The points should also be checked for satisfactory condition and proper adjustment. Connect the blue wire back to the No. 1 coil. Disconnect the blue wire with the white stripe from the No. 2 coil. Connect the tester and repeat the test given in Step 1. Replacement If the previous tests indicate the coil is unfit for further service, disconnect the coil, remove the attaching hardware, and replace the coil. Bear in mind that the spark plug lead attached to the coil is NOT removeable. A new co il will have the spark plug lead with terminal end attached. After the new coil has been installed and the ground wire properly secured with one of the bolts, coat the connection with some type of neoprene rubber sealer. The sealer will prevent moisture, especially in a salt water atmosphere, from causing corrosion and the ground being lost. Compression A compression check is extremely important, because an engine with low or uneven compression between cylinders CANNOT be tuned to operate satisfactorily. Therefore, it is essential that any compression problem be corrected before proceeding wi th the tune-up procedure. If the powerhead shows any indication of overheating, such as discolored or scorched paint, especially in the area of the top (No. 1) cylinder, inspect the cylinders visu?lly thru the transfer ports for possible scormg. A more thorough inspection can be made if the head is removed. It is possible for a cylinder with sa tis factory compression to be scored slightly. Also, check the water pump. The overheating condition may be caused by a faulty water pump. An overheating condition may also be caused by running the engine out of the water. For unknown reasons, many operators have formed a bad habit of running a small engine without the lower unit being submerged. Such a practice will result in an overheated condition in a matter of seconds. It is interesting to note, the same operator would never operate or allow anyone else to run a large horsepower engine without water circulating through the lower unit for cooling. Bear in mind, the laws governing operation and damage to a large unit ALL apply equally as well to the small engine. Checking Compression 5-Remove the spark plug wires. ALWAYS grasp the molded cap and pull it loose with a twisting motion to prevent damage to - the connection . Remove the spark plugs and keep them in ORDER by cylinder for evaluation later. Ground the spark plug leads to the engine to render the ignition system ALTERNATE LAYERS OF INSULATION --WAXED PAPER ALTERNATE LAYERS OF FOIL TIH OR ALUHINUH I,/ I ' FOIL INSULAT ION Rough sketch to illustrate how the waxed paper, aluminum foil, and insulation are rolled in a typical condenser. Insert a compression gauge into the No. 1, top, spark plug opening. Crank the engine with the starter, or pull on the starter cord, through at least 4 complete piston strokes with the throttle at the wideopen position, or until the highest possible reading: is observed on the gauge. Record the reading. Repeat the test and record the compression for each cylinder. A variation between cylinders is far more important than the actual readings. A variation of more than 5 psi between cylinders indicates the lower compression cylinder may be defective. The problem may be worn, broken, or piston rings, scored pistons, or worn ders. These problems may only be determined after the head has been removed. Removing the head on an outboard engine is not that big a deal, and may save many hours of frustration and the cost of purchasing unnecessary parts to correct a faulty condition. Condenser In simple terms, a condenser is composed of two sheets of tin or aluminum foil laid one on top of the other, but separated by a sheet of insulating material such as waxed paper, etc. The sheets are rolled into a cylinder to conserve space and then inserted into a metal case for protection and to permit easy assembly. The purpose of the condenser is to absorb or store the secondary current built up in the primary winding at the instant the breaker points are separated. By absorbing or storing this current, the condenser prevents excessive arcing and the useful life of the breaker points is extended. The condenser also gives added force to the charge produced in the secondary winding as the condenser discharges. LOW TENSION MAGNETO 5-3 1 Worn and corroded breaker points unfit for further service. Modern condensers seldom cause problems, therefore, it is not necessary to install a new one each time the points are replaced. However, if the points show evidence of arcing, the condenser may be at fault and shoulcl be replaced. A faulty condenser may not be detected without the use of special test equipment. The modest cost of a new condenser justifies its purchase and installation to eliminate this item as a source of trouble. Breaker Points The breaker points in an outboard motor are an extremely important part of the ignition system. A set of points may appear to be in good condition, but they may be the source of hard starting, misfiring, or poor engine performance. The rules and knowledge gained from association with 4-cycle engines does not necessarily apply to a 2cycle engine. The points should be replaced every 100 hours of operation or at least once a year. REMEMBER, the less an outboard engine is operated, the more care it needs. Allowing an outboard engine to remain idle will do more harm than if it is used regularly. A breaker point set consists of two points. One is attached to a stationary bracket and does not move. The other point is attached to a movable mount. A spring is used to keep the points in contact with each other, except when they are separated by the action of a cam built into the flywheel or machined on the crankshaft. Both points are constructed with a steel base and a tungsten cap fused to the base. To properly diagnose low tension magneto (spark) problems, the theory of electricity flow must be understood. The flow of electricity through a wire may be compared with the flow of water through a pipe. Consider the voltage in the wire as the water pressure in the pipe and the amperes 5-32 IGNITION as the volume of water. Now, if the water pipe is broken, the water does not reach the end of the pipe. In a similar manner if the wire is broken the flow of electricity is broken. If the pipe springs a leak, the amount of water reaching the end of the pipe is recuced. Same with the wire. If the installation is defective or the wire becomes grounded, the amount of electricity (amperes) reaching the end of the wire is reduced. Check the wiring carefully, inspect the points closely and adjust them accurately. The point setting for ALL engines covered in this section is 0.020" for a used set of points and 0.022" for a new set. NEVER file the points. DO NOT change the breaker arm spring tension. SERVICING LOW TENSION MAGNETO IGNITION SYSTEM General Information Magnetos installed on outboard engines will usually operate over extremely long periods of time without requiring adjustment or repair. However, if ignition system problems are encountered, and the usual corrective actions such as replacement of spark plugs does not correct the problem, the low-tension magneto output should be checked to determine if the unit is functioning properly. Magneto overhaul procedures may differ slightly on various outboard models, but the following general basic instructions will apply to all Johnson/Evinrude high speed flywheel- type low-tension magnetos. REMOVAL 1-Remove the hood or enough of the engine cover to expose the flywheel. Disconnect the battery connections from the battery terminals, if a battery is used to crank the engine. If a hand starter is HAND STARTER installed, remove the attaching hardware from the legs of the starter assembly and lift the starter free. On hand started models, a round ratchet plate is attached to the flywheel to allow the hand starter to engage in the ratchet and thus turn the flywheel. This plate must be removed before the flywheel nut is removed. 2-Remove the nut securing the flywheel to the crankshaft. It may be necessary to use some type of flywheel strap to prevent the flywheel from turning as the nut is loosened. 3-Install the proper flywheel puller using the same screw holes in the flywheel that are used to secure the ratchet plate (if installed). NEVER attempt to use a puller which pulls on the outside edge of the flywheel or the flywheel may be damaged. After the puller is installed, tighten the center screw onto the end of the crankshaft. Continue tightening the screw until the fly wheel is released from the crankshaft. Re move the flywheel. DO NOT strike the puller center bolt with a hammer in an attempt to dislodge the flywheel. Such action could seriously damage the lower seal and/ or lower bearing. 4-STOP, and carefully observe the magneto and associated wiring layout. Study how the low-tension magneto is assembled. TAKE TIME to make notes on the wire routing. Observe how the heels of the laminated core, with the coil attached, is flush with the boss on the armature plate. These items must be replaced in their proper positions. You may elect to follow the practice of many professional mechanics by taking a series of photographs of the engine with the flywheel removed: one from the top, and a couple from the sides showing the wiring and arrangement of parts. Breaker Points/Condenser Service The armature plate does not have to be removed to service the low-tension magneto. If it is necessary to remove the plate for other service work, such as to replace the top seal, see Step 12. For simplid ty and dar ity, the following procedures and accompanying illustrations cover a two-cylinder ignition system. 5-Remove the screw attaching tbe wires from the driver coil and condenser to LOW TENSION MAGNETO 5-33 one set of points. On engines equipped with a key switch, or "kill" button S\vitch, a ground wire is also connected to this screw. · 6-Using a pair of needle-nose pliers remove the wire clip from the post protruding through the center of the points. 7-Remove the hold-down screw securing the point set to the armature plate. 5-34 IGNITION 8-Lift the point set free of the armature plate. 9-Remove the hold down screw securing the condenser to the armature plate. Ob­serve how the condenser sets into a recess in the armature plate. Repeat the procedure for the other set of points. 10-Remove the two screws through the laminated core of the driver coil and into to the armature plate. Lift the driver coil free. 11-Use a pair of needle-nose pliers and remove the oil wick from the armature plate retainer. Armature Plate Removal First, These Words: It is not necessary to remove the armature plate unless the top seal, or the driver coil leads are to be replaced. 12-Disconnect the armature plate leads and the Packard connectors. The connectors are located at the back of the engine just above the head. Lift the locking tabs upward, and then slide the two halves apart. Disconnect the armature ground wire between the plate and the coil. If the engine being serviced has charge coils, disconnect the yellow, yellow/grey, and yellow/blue stripe leads at the terminal board. Loosen the five screws on the outside edge of the armature plate. These screws are "captive" with the armature plate and need not be removed; Lift the plate free of the engine. 13-Check the nylon retainer to be sure it is clean. Good shop practice dictates to replace the nylon retainer any time the armature plate has been removed. Top Seal Replacement Replacement of the top seal on a Johnson/ Evinrude engine is NOT a difficult task ' . w1 th the proper tools: a seal remover and seal installer. NEVER attempt to remove the seal with screwdrivers, punch, pick, or other similar tool. Such action will most likely damage the collars in the powerhead. Obtain OMC Seal Remover P/N 387780. On newer versions of this tool, a 1-1/8" open end wrench is needed to hold the tool. Older versions are equipped wi th handles. A 3/8" wrench is also needed for the top bolt. 14-To remove the seal, first, work the point cam up and free of the driveshaft. Next, remove the Woodruff key from the crankshaft. A pair of side-cutters is a handy tool for this job. Grasp the Woodruff key with the side-cutters and use the leverage of the pliers against the crankshaft to remove the key. 1..5-Work the special tool into the seal. Observe how the special tool is tapered and has threads. Continue working and turning the tool until it has a firm grip on the inside of the seal. Now, tighten the center screw of the puller against the end of the crankshaft and the seal will begin to lift from the collars. Continue turning this center screw LOW TENSION MAGNETO 5-35 until the seal can be raised manually from the crankshaft. 16-To install the new seal: Coat the inside diameter of the seal with a thin layer of oil. Apply OMC sealer to the outside diameter of the seal. Slide the seal down the crankshaft and start it into the recess of the powerhead. Use the special tool and work the seal completely into place in the recess. Install the Woodruff key into the crankshaft keyway. Observe the difference to the sides of the cam. On almost all cams, the word TOP is stamped on one side. Also, on some cams, the groove does not go all the way through. Therefore, it is very 5-36 IGNITION difficult to install the cam incorrectly, with the wrong side up. Slide the cam down the crankshaft with the word TOP facing upward. Continue working the cam down the crankshaft until it is in place over the Woodruff key. CLEANING AND INSPECTING Inspect the flywheel for cracks or other damage, especially around the inside of the center hub. Check to be sure metal parts have not become attached to the magnets. Verify each magnet has good magnetism by using a screwdriver or other tool. Thoroughly clean the inside taper of the flywheel and the taper on the crankshaft to prevent the flywheel from "walking" on the crankshaft while the engine is running. Check the top seal around the crankshaft to be sure no oil has been leaking onto the armature plate. If there is ANY evidence the seal has been leaking, it MUST be replaced, as outlined earlier in this section. Clean the surface of the armature plate where the points and condenser attach. Install a new condenser into the recess and secure it with the hold-down screw. ASSEMBLING Armature Plate Installation 1-By volume, mix one part molybdenum sulfide to forty parts OMC Sea-Lube (Trade Mark) Anti-Corrosion Lube. Coat the crankcase boss (the armature plate pilot) with the mixture. Coat the Delrin ring with OMC outboard lubricant, and then install the ring over the edge of the retainer plate. Place the support plate in position on the crankcase. Position the retainer plate over the support plate and align the holes with the holes in the crankcase. Secure the retainer plate with the attaching screws. Tighten the screws EVENLY and ALTERNATELY. 2-Carefully slide the armature plate down over the crankshaft. TAKE CARE not to damage the breaker arms. Compress the Delrin ring with a pair of needle nose pliers and locate the armature plate over the Delrin ring. Align the holes in the armature plate with the holes in the support. Secure the support plate with the attaching screws. Tighten the scre\vs EVENLY and ALTERNATELY. Connect the electrical wires, connectors, and the retainer plate to the control shaft arm with the washer beneath the retainer plate link Tighten the Phillips screws on the outside perimeter of the armature plate. Tighten the screws ALTERNATELY and EVENLY. LOW TENSION MAGNETO 5-37 3-Slide a NEW oil wick down into the armature plate retainer. Check to be sure at least half of the wick makes contact with the cam. 4-Position the driver coil in place on the armature plate. Secure the coil in place with the two screws through the laminated core and into the armature plate. Do not tighten the two screws at this time. 5-To adjust the driver coil and charge coils on electric start models, a special coil locating ring tool is required that fits down over the armature plate. This tool will locate the driver coil properly in relation to the flywheel. Install this special tool over the armature plate. Push outward on the coil and secure the two screws. 6-If a special ring tool is not available, and in an emergency, hold a straight edge against the boss on the armature plate and bring the heel of the laminated core out 5-38 IGNITION square against the edge of the boss on the armature plate. Tighten the two scr..ws through the laminated core of the dnver coil. Testing the Driver Coil 7-Check to be sure the driver coil leads are disconnected from the point set. Connect the driver coil leads to an ohmmeter. Set the meter to the low ohms scale. The coil is fit for service if the resistance indica ted is 1.45 :!:o.4 ohm. GOOD WORDS The points MUST be assembled BEFORE they are installed onto the armature plate. One side of each point set has the base and is non-moveable. The other side of the set has a moveable arm. A small wire clip is included in each point set package. This clip is used on top of the post. 8-Slide the moveable portion of the point set down over the post and onto the base. Check to be sure the spring tension of the moveable arm is on the inside of the right angle arm. After the moveable arm is in place, use the screw from the old set of points and thread it through the right angle arm into the spring tension lever of the moveable arm. The points are now ready for installation onto the armature plate. 9-Position the assembled point set in place on the armature plate. Install the screw with the wavy washer under the head. Tighten the screw securely into the armature plate. 10-Install the wire clip into the groove of the post. Condenser Installation 11-Position the condenser into place in the armature plate recess. Secure the condenser in place with the attaching screw. CRITICAL WORDS As the driver coil, condenser, and "kill" switch wire are being attachec to the point set, take the following precautions and make these adjustments: a-The wire between the driver coil and the points should be tucked onto the armature plate and as far away from the crankshaft as possible. b-The condenser wire leaving the top of the condenser and connected to the point set should be bent downward to prevent the fly..heel from making contact with the wire. A countless number of installations have been made only to have the flywheel rub against the condenser wire and cause failure of the ignition system. c-Check to be sure all wires connected to the point set are bent downward toward the armature plate. The wires MUST NOT touch the plate. If any of the wires make c..ntact with :the armature plate, the ignitiOn system w1ll be grounded and the engine will fail to start. 12-Connect the wire leads to the set of points. For the second set of points and condenser, repeat Steps 8 thru 12, including th.. Good Words prior to Step 8 and the Cntcal Words following Step 11. GOOD WORDS The point spring tension is predetermined at the factory and does not require . adJustment. Once the point set is properly installed, all should be well. In most cases, breaker contact and alignment will not be necessary. If a slight alignment adjustment should be required, CAREFULLY bend the insulated part of the point set. Point Adjustment 13-Install the flywheel nut onto the end of the crankshaft. Now, turn the crankshaft clockwise and at the same time observe the cam on the crankshaft. Continue turning the crankshaft until the rubbing block of the ' point set is at the high point of the cam. At this position, use a wire gauge or feeler gauge and set the points at 0.020" for a used set of points and at 0.022" for a new set. This setting is good for all models covered this section. A wire gauge will always i.. g1ve a more accurate adjustment than a feeler gauge. Work the gauge between the points and, at the same time, turn the eccentric on the armature plate until the proper adjustment is obtained. Rotate the crankshaft a complete revolution and again check the gap adjustment. After the crank- LOW TENSION MAGNETO 5-39 shaft has been turned and the points are on the high point of the cam, check to be sure the hold-down screw is tight against the base. There is enough clearance to allow the eccentric on the base points to turn. If the hold-down screw is tightened AFTER the point adjustment has been made, it is very likely the adjustment will be changed. Follow the same procedure and adjust the other set of points. Remove the nut from the crankshaft. Flywheel Installation 14-Check to be sure the flywheel magnets are free of any metal parts. 15-If the key is not already in place, position the key in the crankshaft keyway. Check to be sure the inside taper of the flywheel and the taper on the crankshaft are clean of dirt or oil, to prevent the flywheel 5-40 IGNITION from "walking" on the crankshaft while the engine is operating. Slide the flywheel down over the crankshaft with the keyway in the flywheel aligned with the key on the crankshaft. Rotate the flywheel clockwise and check to · be sure the flywheel does not contact any part of the low-tension magneto or the wiring. 16-If servicing a model with the hand starter mounted on top, place the ratchet for the starter on top of the flywheel and install the three 7 /16" screws. On some model engines, a plate retainer covers these screws. Thread the flywheel nut onto the crankshaft and tighten it to the torque value given in the Appendix. After the ratchet plate and flywheel nut have been installed, install the hand starter over the flywheel. Check to be sure the ratchet engages the flywheel properly. 17-Set the gap on each spark plug at 0.030". Some model engines clo not require a gap setting. Install the spark plugs and tighten them to the correct torque value. Spark plugs, 1971-81: 210-246 in lbs. Spark plugs, 1982 and on: 216-252 in lbs. Connect the battery leads to the battery terminals, if a battery is used with a starter motor to crank the powerhead. To synchronize the ignition system with the fuel syst..m, see Section 5-9. Replace worn spark plugs with new ones and tighten them to the required torque value. 5-7 TYPE I CAPACITOR DISCHARGE (CD) FLYWHEEL MAGNETO WITH TIMER BASE This section covers the following horsepower units and model years: 50 hp --1971-75 55 hp --1976-77 DESCRIPTION READ AND BELIEVE. A battery installed to crank the engine DOES NOT mean the engine is equipped with a battery-type ignition system. A magneto system uses the battery only to crank the engine. Once the engine is running, the battery has absolutely no affect on engine operation. Therefore, if the battery is low and fails to crank the engine properly for starting, the engine may be cranked manually, started, and operated. Under these conditions, the key switch must be turned to the ON position or the engine will not start by hand cranking. A magneto system is a self-contained unit. The unit does not require assistance from an outside source for starting or continued operation. Therefore, as previously mentioned, if the battery is dead, the engine may be cranked manually and the engine started. The capacitor discharge (CD) magneto ignition system consists of the flywheel and ring gear assembly; timer base and sensor assembly installed under the flywheel; a Power Pack installed on the starboard side of the powerhead; and two ignition coils mounted at the rear of the powerhead. On some models, an alternator stator and charge coils assembly is installed directly under the flywheel. The spark plugs might be considered a part of the ignition system. Repair of these components is not possible. Therefore, if troubleshooting indicates a part unfit for further service, the entire assembly must be removed and replaced in order to restore the outboard to satisfactory performance. As an example the coil and coil wire leading to the spark plug is one assembly. If the coil or wire is found to be faulty the coil and wire must be replaced as an assembly. Before performing maintenance work on the system, it would be well to take time to read and understand the introduction information presented in Section 5-l at the beginning of this chapter, the Description at TYPE I CD WITH TIMER BASE 5-4 1 the start of this section, and the Theory of Operation in the following paragraphs. THEORY OF OPERATION This system generates approximately 30,000 volts which is fed to the spark plugs without the use of a point set or an outside voltage source. To understand how high voltage current is generated and reaches a spark plug, imagine the flywheel turning very slowly. As the flywheel rotates, flywheel magnets induce current in the a1ternator stator and also generate about 300 volts AC in the charge coils. Therefore, no external voltage source is required. The 300 volts AC is converted to DC in the Power Pack, and is stored in the Power Pack capacitor. Sensor magnets ar.. a part of the flywheel hub. Gaps exist between the sensor magnets. As one gap passes the sensor coil, voltage is generated. This small voltage generated in the sensor coil activates one of two electronic switches in the Power Pack. The switch discharges the 300 volts stored in the capacitor into one of the ignition coils. The ignition coil .. FLYWHEEL NUT TIMER BASE TIMER BASE . Exploded drawing of a typical flywheel, stator, timer base, and timer base retainer arrangement. 5-42 IGNITION steps the voltage up to approximately 30..000 volts. This high voltage is fed to the spark plug igniting the fuel/air mixture in the cylinder. Now, as the flywheel continues to rotate, the· next sensor magnet gap on the flywheel hub, which is opposite in polarity from the first, generates a reverse polarity voltage in the sensor coil. This voltage activates the second electronic switch in the Power Pack, and discharges the capacitor into the other ignition coil. The voltage is stepped up to approximately 30,000 volts and fed to the next spark plug. The cycle is repeated as the flywheel continues to rotate. TROUBLESHOOTING Always attempt to proceed with the troubleshooting in an orderly manner. The shotgun approach will only result in wasted time, incorrect diagnosis, replacement of unnecessary parts, and frustration. Begin the ignition system troubleshooting with the spark plug/s and continue through the system until the source of trouble is located. The following test equipment is a MUST when troubleshooting this system. Stating it another way, "There is no way on this green earth to properly and accurately test the complete system or individual coMponents without the special items listed." Continuity Meter Ohmmeter Timing Light S-80 or M-80 neon test light. Neon spark tester. SAFETY WORDS This system generates approximately 30,000 vel ts which is fed to the spark plugs. Therefore, perform each step of the troubleshooting procedures exactly as presented as a precaution against personal injury. The following safety precautions should always be observed: DO NOT attempt to remove any of the potting in the back of the Power Pack. Repair of the Power Pack is impossible. 00 NOT attempt to remove the high tension leads from the ignition coil. DO NOT open or close any plug-in connectors, or attempt to connect or disconnect any electrical leads while the engine is being cranked or is running. DO NOT set the timing advanced any further than as specified. DO NOT hold a high tension lead with your hand while the engine is being cranked or is running. Remember, the system can develop approximately 30,000 volts which will result in a severe shock if the high tension lead is held. ALWAYS use a pair of approved insulated pliers to hold the leads. DO NOT attempt any tests except those listed in this troubleshooting section. DO NOT connect an electric tachometer to the system unless it is a type which has been approved for such use. DO NOT connect this system to any voltage source other than given in this troubleshooting section. ONE MORE WORD: Each cy Iinder has its own ignition system in a flywheel-type ignition system. This means if a strong spark is observed on any one cylinder and CHARGE COIL I ___ __ r ELECTRONIC SWITCHES (SILICON CONTROLLED POWER RECTIFIER) PACK II Functional diagram of a typical Type I CD flywheel magneto ignition system ;vith timer base. not at another, only the weak system is at fault. However, it is always a good idea to check and service all systems while the flywheel is removed. Preliminary Test The first area to check on a CD flywheel magneto ignition system is the system ground. Connect one lead of a continuity meter to the No. 4 Power Pack terminal and the other lead to a good ground. The meter should indicate continuity. Also check the battery charge. If the battery is below a full charge it will not be possible to obtain full cranking speed during the tests. Compression Check A compression check is extremely important, because an engine with low or uneven compression between cylinders CANNOT be tuned to operate satisfactorily. TYPE I CD WITH TIMER BASE 5-43 Therefore, it is essential that any compression problem be corrected before proceeding with the tune-up procedure. See Chapter 3. If the powerhead shows any indication of overheating, such as discolored or scorched paint, especially in the area of the top (No. 1) cylinder, inspect the cylinders visually thru the transfer ports for possible scoring. A more thorough inspection can be made if the head is removed. It is possible for a cylinder with satisfactory compression to be scored slightly. Also, check the water pump. The overheating condition may be caused by a faulty water pump. An overheating condition may also be caused by running the engine out of the water. For unknown reasons, many operators have formed a bad habit of running a small engine without the lower unit being submerged. Such a practice will result in an overheated condition in a matter of seconds. It is interesting to note, the same opera tor would never operate or allow anyone else to run a large horsepower engine without water circulating through the lower unit for cooling. Bear in mind, the laws governing operation and damage to a large unit ALL apply equally as well to the small eng.ine. Spark Plugs 1-Check the plug wires to be sure they are properly connected. Check the entire length of the wire/s from the plug/s to the coils. If the wire is to be removed from the spark plug, ALWAYS use a pulling and twisting motion as a precaution against damaging the connection. 2-Attempt to remove the spark plug/s by hand. This is a rough test to determine if the plug is tightened properly. You should not be able to remove the plug without using the proper socket size tool. Remove the spark plug/s and keep them in order. Ex Po;•·er pack terminal identification: 1-Charge coil, brown; 2-Ignition coil No. 1, orange; 3-Ignition coil No. 2, orange; 4-Ground lead, black; 5-Key switch, black/yellow; 6-Sensor, white/black; 7-Sensor, black/white; 8-Vacant. 5-44 IGNITION amine each plug and evaluate its condition as described in Section 5-2. If the spark plugs have been removed and . the problem cannot be determined, but the plug appears to be in satisfactory conditio?, electrodes, etc., then replace the plugs m the spark plug openings. 3-A conclusive spark plug test should always be performed with the spark plugs installed. A plug may indicate satisfactory spark when it is remove? and teste?, but . under a compression condition may fail. An example would be the possibility of a person being able to jump a giv..n d..stance on t..e . ground, but if a strong wmd IS blowmg, his distance may be reduced by half. The same is true with the spark plug. Under good compression in the cylinder, the spark may be too weak to ignite the fuel properly. Therefore, to test the spark plug under compression, replace it in the engine and tighten it to the prop er torque ..alu... A . nother reason for testmg for sparK w1th the plugs installed is to duplicate actual operating conditions regarding flywheel speed. If the flywheel is rotated with the pull cord with the plugs removed, the flywheel will rotate much faster because of the no-compression condition in the cylinder, giving the FALSE indication of satisfactory spark. Damaged spark plugs. Notice the broken electrode on the left plug. The broken part MUST be for;rtd and removed before returning the powerhead to servzce. Checking Compression 4-Remove all the spark plugs. Ground the spark plug leads to the engine to render the ignition system inoperative while performing the compression check. Insert a compression gauge into the No. 1, top, spark plug opening. Crank the engine with the starter, or pull on the starter cord, through at least 4 complete piston strokes with the throttle at the wideopen position, or until the highest possible reading is observed on the gauge. Record the reading. Repeat the test and record the compression for each cy llnder. A variation between cylinders is far more important than the actual readings. A variation of more than 5 psi between cylinders indicates t..e lower compression cylinder may be defective..he : . problem may be worn, broken, or sticK:ng piston rings, scored pistons or worn cylmders. These problems may only be determined after the head has been removed. Removing the head on an outboard engine is not that big a deal, and may save many hours of frustration and the cost of purchasing unnecessary parts to correct a faulty condition. A spark tester capable of testing for spark while cranking and also while the engine is operating, can be purchased from almost any automotive parts supply store. Test No. 1 Ignition Coil Output Check Use a spark tester and check for spark at each cylinder. If a spark tester is not available, use a pair of insulated pliers and hold the' plug wire about 1/4-inch from the engine. Turn the flywheel with a pull starter or electrical starter and check for spark. A strong spark over a wide gap must be observed when testing in this manner, because under compression a strong spark is necessary in order to ignite the air/fuel mixture in the cylinder. This means it is possible to think you have a strong spark, when in reality the spark will be too weak when the plug is installed. If there is no spark, or if the spark is weak, from one coil, proceed directly to Test No. 2, Trigger Coil Input Check. If there is no spark or the spark is weak from both coils, proceed directly to Test No. 5, Charge Coil Output Check. If the spark is strong and steady, across the 1/4-inch gap indicating it is satisfactory, then the problem is in the spark plugs, the fuel system, or the compression is weak. Test No. 2 Trigger Coil Input Check Remove the Power Pack cover, and then disconnect the sensor leads from the No. 6 and No. 7 terminals. Obtain a neon tester, No. S-80 or M-80. If one of these testers is not available, a 1-1/2 volt battery with a short lead soldered to each terminal may be TYPE I CD WITH TIMER BASE 5-45 used. If neither of these items are available, an ohmmeter may be used. Connect the black lead of the neon tester to the No. 6 terminal and the blue lead to the No. 7 terminal. Set the neon light selector to the No. 3 position. Crank the engine with the electric starter motor, and at the same time depress the "B" load button rapidly. Stop, reverse the lead at the No. 6 and No. 7 terminals. Repeat the cranking and depressing procedure. Observe the spark across the tester. If both coils fired at the same time, during this test, the Power Pack is at fault. Only one coil should fire when the button is depressed. If the neon tester is not available, an assistant is required. Have the assistant make contact with the two leads from the small 1-1/2 volt battery to the No. 6 and No. 7 terminals while the engine is being cranked. Reverse the leads at the No. 6 and No. 7 terminals and repeat the test. One coil should fire \Vhen the leads are connected one way and the other coil flre when the leads are reversed. a-If adequate spark was observed from both coils in the previous tests, the problem is in the sensor. To test the sensor assembly, see Test No. 3 and Test No. 4. b-If no spark was observed from either coil during the previous tests, the charge coil must be checked as outlined in Test No. 5. c-If spark was observed on only one coil, the Power Pack must be checked, see Test No. 6. TEST 1 TEST 2 5-46 IGNITION Test No. 3 Sensor Coil Low Ohm Check Disconnect the sensor leads from the Power Pack trerminals No. 6 and No. 7. Connect the ohmmeter leads to the sensor coil leads' (the white lead with the black stripes and the black lead with white stripes). Use the low ohm scale and observe the reading. The meter should indicate 15.0 !5.0 ohms at room temperature (70 ° F). If the ohmmeter reading is not satisfactory, proceed as follows: Turn the ohmmeter to the Hi..h Ohm scale. The meter should indicate zero ohms --no reading. If the test fails, the sensor coil and timer base must be replaced as a unit. If the test is successful disconnect the ohmmeter and connect the lead at the No. 6 and No. 7 Power Pack terminals. If the test is not successful, proceed with the next test, Sensor Coil High Ohm Test. Test No. 4 Sensor Coil High Ohm Check Move the ohmmeter to the High Ohm scale. With the sensor leads still disconnected from the Power Pack, as in Test No. 3, connect the red ohmmeter test lead to either one of the sensor leads. Connect the black ohmmeter lead to a good ground. The meter should indicate infinity. Any resistance indicates a short to ground. If the test fails, the sensor coil and timer base must be replaced as a unit. If the test is successful disconnect the ohmmeter and connect the leads at the No. 6 and No. 7 Power Pack terminals. Test No . ..5 Charge Coil Output Check Connect the black lead from the S-80 or M-80 neon tester to the Power Pack No. 1 terminal. Connect the tester blue lead to the No. 4 Power Pack terminal, or to a good ground on the engine. (The No. 4 terminal is ground.) Turn the neon tester to position No. 2. If a neon test light is being used, connect one lead to the Power Pack No. 1 terminal and the other lead to the No. 4 Power Pack terminal or a good ground on the engine. Crank the engine and at the same time, depress load bu tton ''B" on the tester. Observe the light. If the ligh t glows steadily, the charge coils are good. Check the Power Pack outpu t. Disconnect the coil lead at terminal No. 1 on the Power Pack. Connect the black tester lead to the wire just removed from the Power Pack terminal. Crank the engine. If the neon light glows intermi ttently or does not glow at all, the charge coil and stator assembly must be replaced. If a neon tester is not available, obtain an ohmmeter. Disconnect the lead at the No. 1 Power Pack terminal. Connect one ohmmeter lead to the lead just disconnected from the terminal and the other ohmmeter lead to a good ground. Use the high ohmmeter scale and observe the reading. The meter should indicate 750 !75 ohms at room temperature (70°F). If the proper reading cannot be obtained, the charge coil and stator must be replaced as an assembly. Test No. 6 Power Pack Output Check Check all connections at the Power Pack to be sure they are clean and secure. Disconnect the lead from the No. 2 and No. 3 terminals. If the S-80 or M-80 neon tester is used, connect the black lead to the No. 2 Power Pack terminal and the blue lead to a good ground or to the No. 4 terminal. If a neon test light is used, connect one lead to the No. 2 terminal and the other lead to a good ground or the No. 4 terminal. Move the neon tester switch to the No. 1 posi ton, and then depress load button "A" and crank the engine with the electric starter motor. Observe the light. If the test light is used, crank the engine with the electric starter motor and observe the light. Now, move the lead from the No. 2 terminal to the No. 3 TYPE I CD WITH TIMER BASE 5-47 terminal. Crank the engine again and observe the light. If the light is strong and steady on both outputs, replace the faulty coil or coils. The No. 2 terminal connection is the top coil and the No. 3 terminal is the bottom coil. If no light is visible on both outputs, check the key switch as outlined in Key Switch Check, Test No. 7. If a steady light was observed on one output but no light on the other, replace the Power Pack. If the light was very dim or intermittent on one or both outputs during the tests, the Power Pack must be replaced. Connect the wires disconnected at the start of the tests. Test No. 7 Key Switch Check A magneto key switch operates in REVERSE of any other type key switch. When the key is moved to the OFF position, the circuit is CLOSED between the magneto and ground. In some cases, when the key is turned to the OFF position the points are grounded. For this reason, an automotivetype switch MUST NEVER be used, because the circuit would be opened and closed in reverse, and if 12-volts should reach the coil, the coil will be DESTROYED. Connect the spark tester to the high tension leads. Disconnect the lead at the No. 5 Power Pack terminal. This is the wire from the key. Crank the engine with the key and observe the spark. 5-48 IGNITION If there is no indication of spark on either coil or on only one, replace the Power Pack. If spark is indicated on both coils, the problem is most likely in the lead from the key. · . If the key switch leads appear to be m good condition, replace the key switch. SERVICING THE TYPE I CD FLYWHEEL MAGNETO IGNITION WITH TIMER BASE General Information CD magneto systems installed on outboard engines will usually operate over ..xtremely long periods of time without reqUiring adjustment or repair. However, if ignition system problems are encountered, and the usual corrective actions, such as replacement of spark plugs, does not correct the problem, the magneto output should be checked to determine if the unit is functioning properly. CD magneto overhaul procedures may differ slightly on various outboard models but the following general basic instructions will apply to all Johnson/Evinrude high speed flywheel-type CD magnetos. STATOR AND CHARGE COIL REPLACEMENT Removal 1-Hold the flywheel with a proper tool and remove the flywheel nut. Obtain special tool OMC No. 378 103 or an equivalent puller. NEVER use a puller that exerts a force on the rim or ring gear of the flywheel. Remove the flywheel. Observe closely how the stator and trigger base is secured to the powerhead. You may elect to follow the practice of professional mechanics and take a picture with a polaroidtype camera as an aid during the assembling and installation work. 2-Disconnect the wires at the terminal block and Power Pack. The leads from the charge coil are connected to the No. 1 terminal of the Power Pack and the leads from the stator are connected to the No. 1 and No. 2 terminals of the terminal board. Remove the four screws securing the stator to the powerhead. Lift the stator and charge coil assembly free of the powerhead. The stator CANNOT be repaired. Therefore, if troubleshooting and testing indicates the stator or the charge coil are unfit for service, the complete unit must be replaced as an assembly. Stator assembly showing the two charge coils and the generating coils. TYPE I CD ¥liTH TIMER BASE 5-49 Installation 3-Slide the stator assembly down the crankshaft and into place on the powerhead. Apply just a drop of Locti te to the threads of the attaching screws, and then install and tighten them ALTERNATELY and EVENLY to the torque value given in the Appendix. 4-Check the crankshaft and flywheel tapers for any traces of oil, burrs, nicks, or other damage. Clean the tapered surfaces with solvent, and then blow them dry with compressed air. These two surfaces MUST be absolutely dry. Slide the flywheel onto the crankshaft with the slot in the flywheel indexed over the Woodruff key in the crankshaft. Thread the flywheel nut onto the crankshaft. Hold the flywheel from rotating with a proper tool and tighten the nut to the torque value given in the Appendix. TIMER BASE AND SENSOR ASSEMBLY REPLACEMENT Removal 1-Remove the stator and charge coil assembly as outlined elsewhere in this section. Remove the four retaining clips and screws. The clips engage in a Delrin ring which fits around the timer base. Lift the timer base and Delrin free of the powerhead. GOOD WORDS A brass bushing is an integral part of the timer base. This bushing has a very close tolerance with the upper bearing and seal assembly. The bushing rotates as the spark is advanced or retarded. After the assembly has been removed, make a careful check for dirt, chips, or damage which might prevent the timer base from rotating freely, reference illustra tion "A" and "8". 5-50 IGNITION Installation 2-Coat the upper bearing and seal assembly with OMC Sea-Lube (Trade Mark) or equivalent. Apply a coating of light-weight oil to the Delrin ring. Slip the ring into place on the timer base. Position the timer base assembly into position on the powerhead and secure it with the four retaining clips and screws. If the Woodruff key on the crankshaft was removed, insert it into the keyway with the outer edge of the key parallel to the centerline of the crankshaft. Install the stator assembly and flywheel. POWER PACK REPLACEMENT Removal 3-Disconnect the battery from the engine. Disconnect all leads at the Power Pack terminal board. Remove the attaching hardware and lift the Power Pack free of the powerhead. Installation Place the new Power Pack in place on the powerhead. Secure it with the attaching hardware. Connect the electrical leads to the terminal board following the color code designations given on the Power Pack cover. Install and secure the cover in place. Power pack terminal identification: 1-Charge coil, brown; 2-Ignition coil No. 1, orange; 3-Ignition coil No. 2, orange; 4-Ground lead, black; 5-Key switch, black/yellow; 6-Sensor, white/black; 7-Sensor, black/white; 8-Vacant. TIMING CHECK AND ADJUSTMENT GOOD WORDS Under normal operating conditions, the timing should not change. If the spark advance stop screw has been moved, or if the Power Pack assembly has been replaced, the timing should be checked. The timing CANNOT be properly or accurately adjusted without a timing light. The engine MUST be mounted in a test tank or body of water to adjust the timing. NEVER attempt to make this adjustment with a flush attachment connected to the lower unit. The no-load condition on the propeller would cause the engine to RUN re suiting serious damage in de AWAY or TYPE II CD WITH SENSOR COIL 5-51 setting. One full turn of the screw will 1° result in approximately of adjustment. Again start the engine and check the degree reading. Tighten the locknut securely after the final adjustment. Sychronizing To synchronize the ignition system with. the fuel system, see Section 5-9. 5-8 TYPE ll CD FLYWHEEL MAGNETO IGNITION WITH SENSOR COIL 2.5 hp 1987 & on 15 hp 1977 & on 4 hp 1984-85 20 hp 1981 & on 4.5 hp 1980-84 25 hp 1977 & on 1985 & on 1984-85 30 hp struction of the unit. 6 hp CAUTION: Water must circulate through the lower unit to the engine any time the en 6 hp 1977-79 35 hp 1977-84 1982 & on 40 hp 1984 & on 1978 & on gine is run to prevent damage to the water pump in the lower unit. Just five seconds without water will damage the water pump. 9.9 hp 1977 & on 60hp 1980-85 7.5 hp 1980-83 50 hp 8 hp 1984 & on 55 hp 1978-83 1-As a preliminary adjustment, loosen the locknut on the spark advance screw and rotate the screw inward or outward until the exposed portion of the screw outside the bracket is 1/2" (12.7 mm). 2-Connect the timing light to the No. 1 cylinder. Start the engine. With the unit in neutral or in gear, set engine speed to a minimum of 3500 rpm, full spark advance. The spark advance should be as listed in the Appendix. If necessary, advance or retard the spark to obtain the proper degree reading, as follows: Shut down the engine. Loosen the locknut and move the advance stop adjustment screw to obtain the proper DESCRIPTION READ AND BELIEVE. A battery installed to crank the engine DOES NOT mean the engine is equipped with a battery-type ignition system. A CD magneto system uses the battery only to crank the engine. Once the engine is running, the battery has absolutely no affect on engine operation. Therefore, if 5-52 IGNITION the battery is low and fails to crank the engine properly for starting, the engine may be cranked manually, started, and operated. Under these conditions, the key switch must be turned to the ON position or the engine will not start by hand cranking. A CD magneto system is a self-contained unit. The unit does not require assistance from an outside source for starting or continued operation. Therefore, as previously mentioned, if the battery is dead, the engine may be cranked manually and the engine started. The Type II capacitor discharge (CD) ignition system consists of the following assemblies: flywheel, charge coil, sensor, power pack, and ignition coils. The flywheel assembly contains two in ° tegral magnets installed 180 apart. These magnets are charged with opposite polarity. The charge coil assembly is composed of a large coil of wire which generates alternating current (ac). The current is fed into the Power Pack. The sensor assembly consists of a small coil of wire which generates the triggering voltage necessary for the Power Pack. In simple terms, the Power Pack contains the electronic circuits required to produce ignition at the proper time. The ignition coils generate approximately 30,000 volts which is fed to the spark plugs to ignite the fuel/ air mixture in the cylinders. Before performing maintenance work on the system, it would be well to take time to read and understand the introduction information presented in Section 5-l at the beginning of this chapter, the Description at the start of this section, and the Theory of Operation in the following paragraphs. THEORY OF OPERATION This system generates approximately 30,000 volts which is fed to the spark plugs without the use of a point set or an outside voltage source. To understand how high voltage current is generated and reaches a spark plug, it is well to understand a couple of basic terms used throughout the following paragraphs and troubleshooting procedures. Diode --a small electrical part that allows current to flow in only one direction. On the accompanying diagrams the current flow is indicated by the direction of the arrow. Silicon Controlled Rectifier --commonly referred to as a SCR --a small electrical part in which current can flow through in only one direction, and in which the current can flow only when a "Gate" in the part receives a positive (+) input to trigger or open the gate in the SCR. On the accompanying diagrams the direction of current flow is incUcated by an arrow. Capacitor --a part that stores voltage. One end of the capacitor is positive (+), and the other end is negative (-). The voltage is stored in the capacitor until the trigger circuit is activated. While studying the following circuit explanations, imagine the flywheel turning very, very slowly. Capacitor, Charge Circuit The terms and letter designations are keyed to reference illustration "A", this page. As the flywheel rotates, the magnetic field of a magnet passes through the charge coil winding. As a result, the charge coil produces a small amount of alternating current (AC). This current flows from the charge coil through wire "E" which is positive (+), then enters the Power Pack. It then flows through diode ''B" which applies a positive (+) charge to the ground side of the capacitor. Current flow is blocked by diodes "A" and "C". On the return path, current flows from the capacitor to the charge coil through diode "D" and wire ''F". Alternating current from the charge coil has been changed (rectified) into direct current (DC) for capacitor charge by the four diodes. The diodes maintain a positive (+)charge on the ground side of the capacitor, regardless of the constantly changing charge coil output. Triggering Circuit The terms ancl letter designations are keyed to reference illustration (B). Purpose of the triggering circuit is to control which silicon controlled rectifier (SCR) will turn on and allow the capacitor to discharge. A sensor coil installed under the flywheel produces the signal necessary to turn on the SCR which controls the ignition timing. coil through the grounded primary winding coil through the grounded primary winding TYPE II CD WITH SENSOR COIL 5-53 keyed to reference illustration "C". When SCR No. 1 is triggered, the positive (+) charge stored in the capacitor flows to engine ground, enters the No. 1 ignition S.C.R. #1 ® NO. 1 COIL STOP BUTTON ORKEY Sl/ITCH CHAAGECOIL FLYIIHEEL ----------..J NO. 2 COIL ® After the capacitor is charged, the flywheel continues to rotate so the magnetic field of a magnet passes through the sensor coil winding, producing alternating current. The current leaves the sensor coil through wire "E"' which is positive (+) and enters the Power Pack. Current flows through diode ''B" to the No. 1 SCR gate, turning on SCR No. 1 and then returns to the other side of the sensor coil through diode "D". Current flow is blocked by diodes "A"' and "C". As the flywheel continues to rotate, the oppposite flywheel magent is passed by the sensor coil, current flow is reversed, and wire "F" is positive (+). Current enters the Power Pack and flows through diode "C" to the gate of SCR No. 2 and returns to the other side of the sensor coil through diode "A". Current flow is blocked by diode ''B" and bypasses diode "D". The four diodes in the triggering circuit direct current flow to the SCR gates and back to the sensor. Capacitor Discharge (CD) Circuit The terms and letter designations are wire, and then flows through SCR No. 1 to the other side of the capacitor. During capacitor discharge, current flows through the ignition coil primary winding and SCR No. 1 until the capacitor is discharged and SCR No. 1 turns itself off. The capacitor can now be recharged as described in the capacitor charge circuit paragraphs. Current flowing through the No. 1 ignition coil primary winding produces a large magnetic field surrounding the secondary winding and produces the high voltage to the spark plug to ignite the fuel/air mixture in the cylinder. When SCR No. 2 is triggered, the capacitor is discharged through the No. 2 ignition coil primary winding. Current flows through the SCR No. 2 and returns to the other side of the capacitor. The No. 2 ignition coil then produces the high voltage to the spark plug to ignite the fuel/air mixture in the next cylinder. Ignition Stop/Kill Circuit The terms and letter designations are keyed to reference illustration ''01111• 5-54 IGNITION The capacitor is the heart of the i..nition system. Therefore, the stop button (or key switch) prevents capacitor char)l:e. One end of the capacitor is connected to engine ground. When the stop button (or key switch) is·closed, the capacitor is ..roundec!. When both ends of the capacitor are connected to engine ground, current flow from the charge coil will by-pass the capacitor as shown in reference illustration ''D"'. If the capacitor is not charged, ignition cannot occur. TROUBLESHOOTING Always attempt to proceed with the troubleshooting in an orderly manner. The shotgun approach will only result in wasted time, incorrect diagnosis, replacement of unnecessary parts, ancl frustration. Begin the ignition system troubleshooting with the spark plug/s anc1 continue through the system until the source of trouble is located. Compression A compression check is extremely important, because an engine with low or uneven compression between cylinders CANNOT be tuned to operate satisfactorily. Therefore, it is essential that any compression problem be corrected before proceeding with the tune-up procedure. See Chapter 3. If the powerhead shows any indication of overheating, such as discolored or scorched paint, especially in the area of the top (No. 1) cylinder, inspect the cylinders visually thru the transfer ports for possible scoring. A more thorough inspection can be made if the head is removed. It is possible for a cylinder with satisfactory compression to be scored slightly. Also, check the water pump. The overheating condition may be caused by a faulty water pump. An overheating condition may also be caused by running the engine out of the water. For unknown reasons, many operators have formed a bad habit of running a small engine without the lower unit being submerged. Such a practice will result in an overheated condition in a matter of seconds. It is interesting to note, the same operator would never operate or allow anyone else to run a large horsepower engine without water circulating through the lower unit for cooling. Bear in mind, the laws governing operation and damage to a large unit ALL apply equally as well to the small engine. Checking Compression 1-Remove the spark plug wires. ALWAYS grasp the molded cap and pull it loose with a twisting motion to prevent damage to the connection. 2-Remove the spark plugs and keep them in ORDER by cylinder for evaluation later. Ground the spark plug leads to the engine to render the ignition system inoperative while performing the compression check and to prevent damage to the ignition coil. If a high tension lead is not grounded, the coil will attempt to match the demand created by the spark trying to jump from the electrode to the nearest ground. Insert· a compression gauge into the No. 1 (top) spark plug opening. Crank the engine with the starter, or pull on the starter cord, through at least 4 complete piston strokes with the throttle at the wideopen position, or until the highest possible reading is observed en the gauge. Record the reading. Repeat the test and record the compression for each cylinder. A variation between cylinders is far more important than the actual readings. A variation of more than 5 psi between cylinders indicates the lower compression cylinder may be defective. The problem may be worn, broken, or sticking piston rings, scored pistons or worn cylinders. These problems may only be determined after the head has been removed. Removing the head on an outboard engine is not that big a deal, and may save many hours of frustration and the cost of purchasing unnecessary parts to correct a faulty condition. CHECKING THE TYPE ll SYSTEM The following equipment is required to test the Type II CD Magneto Ignition System. There is no way on this green earth to properly or accurately check the system without the following text equipment: Spark Test --with the air gap adjusted to 1/2 inch (12. 7 mm). Neon Test Light --Model M-80 or S-80 with a 1-1/2 volt battery adapter. If a Model M-90 test light is available an adapter is not necessary. A Stevens or Electro Specialties C.D. Voltmeter Tester will also do the job. Ohmmeter --capable of indicating low ohms (RXl) and high ohms (RXl,OOO). Jumper Wires --four required. These jumper wires may be made using a piece of No. 16 solid wire about 8 inches long with the insulation stripped back about an inch from each end. Spark Plugs 3-Check the plug wires to be sure they TYPE II CD WITH SENSOR COIL 5-55 SPARK PLUG (HI GH-TENS ION) LEAD are properly connected. Check the entire length of the wire/s from the plug/s to the coils. If the wire is to be removed from the spark plug, ALWAYS use a pulling and twisting motion as a precaution against damaging the connection. 4-Attempt to remove the spark plug/s by hand. This is a rough test to determine if the plug is tightened properly. You should not be able to remove the plug without using the proper socket size tool. Remove the spark plug/s and keep them in order. Examine each plug and evaluate its condition as described in Section 5-2. 5-56 IGNITION If the spark plugs have been removed and the problem cannot be determined, but the plug appears to be in satisfactory condition, electrodes, etc., then replace the plugs in the spark plug openings. A conClusive spark plug test should always be performed with the spark plugs installed. A plug may indicate satisfactory spark when it is removed and tested, but under a compression condition may fail. An example would be the possibility of a person being able to jump a given distance on the ground, but if a strong wind is blowing, his distance may be reduced by half. The same is true with the spark plug. Under good compression in the cylinder, the spark may be too weak to ignite the fuel properly. Therefore, to test the spark plug under compression, replace it in the engine and tighten it to the proper torque value. Another reason for testing for spark with the plugs installed is to duplicate actual operating conditions regarding flywheel speed. If the flywheel is rotated with the pull cord with the plugs removed, the flywheel will rotate much faster because of the no-compression condition in the cylinder, giving the FALSE indication of sa tis factory spark. 5-A spark tester capable of testing for spark while cranking and also while the engine is operating, can be purchased from almost any au to motive parts supply store, reference illustration "E". Use a spark tester and check for spark at each cylinder. If the spark tester is used, it should be held at least 2" from any metal part of the engine. If a spark tester is not available, hold the plug wire about 1/4-inch from the engine. Turn the flywheel with a pull starter or electrical starter and check for spark. A strong: spark over a wide gap must be observecl when testing in this manner, because under compression a strong spark is necessary in order to ignite the air.:.. fuel mixture in the cylinder. This means it is possible to think you have a strong spark, when in reality the spark will be too weak when the plug is installed. If there is no spark, or if the spark is weak, the trouble is most likely under the flywheel in the magneto or in the key switch. If a satisfactory spark cannot be obtained, proceed with the troubleshooting as outlined in the following paragraphs. GOOD WORDS Each of the leads from the Power Pack and the leads from under the flywheel have a connector. The leads from the Power Pack to the coils have three-prong connectors. The other connectors for the charge coil and the sensor to the Power Pack each have four-prong connectors. Numerous references to these connectors will be made in the following tests. MORE GOOD WORDS A magneto key switch operates in REVERSE of any other type key switch. When the key is moved to the OFF posi tion, the circuit is CLOSED between the magneto and _ ground. In some cases, when the key is turned to the OFF position the points are grounded. For this reason, an automotivetype switch MUST NEVER be used, because the circuit would be opened and closed in reverse, and if 12-vol ts should reach the coil, the coil will be DESTROYED. Test No. 1 Kill Button or Key Switch Three-prong Connec tor Models Prior to 1986 Separate the three prong connector be t ween the Power Pack and the ignition coils. Set the ohmmeter to the high ohms scale. Connect the ohmmeter red lead to the "A" terminal in the ignition coil end of the connector, and the ohmmeter black lead to a good ground on the engine. If the engine is equipped with a push stop button, proceed as follows: With the button at rest, there should be no continuity. Depress the button --the meter should indicate continuity. If a key switch is used, the meter should indicate continuity with the switch in the OFF position. Turn the key switch to the ON position and the meter should indicate NO continui ty. If there is any needle movement, leave the ohmmeter connected and disconnect the black/yellow stripe wire from the key switch "M" terminal. Now, if the meter indicates an open circuit with the wire disconnected from the key switch, replace the switch or perform Test No. 2, before replacing the switch. TYPE II CD WITH SEI\JSOR COIL 5-57 Illustration sh?w..ng both halves of a five prong . . quzck drsconnect frttmg used since 1986. Identification letters are embossed on the surface next to each term..nal. Use this diagram for reference while performmg the tests on the following pages. If a closed circui t (0 ohms) is indicated, repair or replace the black/yellow strip lead between the key switch and the ignition coil end of the three-prong connector. Test No. 2 Three-prong Connector Kill Bu tton or Key Switch Models Prior to 1986 Five-prong Connec tor Models 1986 and after Separate the three or five prong connector from the Power Pack. Connect jumper wires between the male and female part of the connector, matching color to color, for the four outer terminals. Do not jumper the center terminal marked "E". Crank the engine with the starter motor. If spark is now present but was not with the connector connected, either the key switch is faulty or the stop button is at fault. If there is no spark with this test, continue with the troubleshooting. Test No. 3 Ignition Coil Test Primary Winding Three-prong Connector Models Prior to 1986 Disconnect the spark tester from the engine. Separate the three-prong connector TEST 1 TEST 2 5-58 IGNITION POWER PACK KEY SW ITCH TEST 3 between the Power Pack and the ignition coils. Connect the Red lead of an ohmmeter to the "B" prong in the connec tor to the coils. Connect the Black meter lead to a good ground on the engine. Set the ohmmeter to the low ohm scale. The resistance of the primary winding should be 0.1 +0.05 ohms. - To check the primary winding of the other coil, move the red ohmmeter lead to the "C" prong of plug to the coils. Repeat the tests. The ohmmeter should indicate the same amount of resistance. Five-prong Connector Models 1986 and after Rotate the primary leads (Orange and Orange/Blue) CLOCKWISE to remove them from the primary terminals at the ignition coils. Connect the Red lead of an ohmmeter to the primary terminal at the ignition coil. Connect the Black meter lead to a good ground on the engine. Set the ohmmeter to the low ohm scale. The resistance of the primary winding should be 0.1 +0.05 ohms. - To check the primary winding of the other coil, move the Red ohmmeter lead to POWER PACK 3-WAY KEY PLUG SWI TCH CO IL TEST 4 the primary terminal on the other ignition coils. Repeat the tests. The ohmmeter should indicate the same arnoun t of resistance. Test No. 4 Ignition Coil Test Secondary Winding Three-prong Connector Models Prior to 1986 To check the secondary winding of the coils, connect the Red ohmmeter lead in either "B" or "C", depending on the coil being tested, and the Black test lead to the inside of the high tension spark plug lead. Set the ohmmeter to the high scale. The meter should indicate 275 ohms +50 ohms. Test the other coil in the same manner with the red ohmmeter lead connected to the other point ''B" or "C" and the Black lead to the high tension lead for that coil. Five-prong Connector Models 1986 and after To check the secondary winding of the coils, make contact with the Red ohmmeter lead to the inside of the high tension spark plug lead and the Black test lead to a good ground on the engine. Set the ohmmeter to the high scale. The meter should indicate 275 ohms +50 ohms. Test the other coil in the same manner with the Red ohmmeter lead connected to the other high tension lead and the Black test lead to a good ground on the engine. If either winding --primary or secondary --fails the test, the coil must be replaced. Coil Power Test Very special equipment is required to make a power test of the coil. Therefore, either purchase a new coil or take the old coil to a nearby OMC dealer for a power test. Test No. 5 Sensor Coil Resistance All Models Separate the four or five prong connee tor. This is the connector for the leads from the Power Pack to the armature plate. Insert one end of a jumper wire into ''B" of the female portion of the connector. Insert another jumper wire into "C" of the female portion of the connector. Connect the test leads of an ohmmeter to each of the jumper wires. Set the ohmmeter to the low scale. The sensor coil resistance is satisfactory if the meter indicates 40 +10 ohms. If the resistance is not within this range, replace the sensor coil. Test No. 6 Sensor Coil Testing for a Short All Models Connect the black ohmmeter test lead to the armature plate ground. Connect the red meter lead to the jumper wire connected to terminal "C". Turn the ohmmeter to the high ohm scale. Any meter needle movement indicates the sensor coil or the leads are shorted to ground. A shorted sensor coil MUST be replaced. A shorted sensor coil lead can and MUST be repaired. Disconnect the two jumper wires from "B" and "C". Test No. 7 Charge Coil Resistance Test All Models Insert a jumper wire into terminal "A" in to the female portion of the armature plate connector. Insert a jumper wire into terminal "D" of the connector. Now, connect one meter lead to one jumper wire and the other test lead to the other jumper wire. Set the ohmmeter to the high ohm scale. The meter should indicate 575 ohms ::_75 oms. If servicing an electric start model outboard, the meter should indicate 47 5 ohms +75 ohms. If the resistance is not within the lim ts given, the charge coil MUST be replaced. C..ARGE CO IL TEST 6 TEST 5 TYPE II CD WITH SENSOR COIL 5-59 ARMATURE PLATE 4-IIAY PLUG CHARGE CO IL SENSOR TEST 7 TEST 8 Test No. 8 Charge Coil Testing for a Short Set the ohmmeter to the High Ohm scale. Connec t the black ohmmeter lead to the armature plate ground. Connect a jum per wire to the "A" terminal of the con nector. Connect the red meter lead to the jumper wire. Any meter needle movement indicates the ch::trge coil or the charge coil leads are shorted to ground. A shorted charge coil MUST be replaced. A shorted charge coil lead can and MUST be repaired or replaced. Test No. 9 Charge Coil Output Test An M-80 or S-80 tester can be used for this test. A neon test light available from almost any automotive parts supply store may also be used. Insert a jumper wire into the "A" and "D" pin holes in the armature plate side of the connector. Connect the neon test leads or the neon test light leads to the jumper wires. ARMATURE PLATE 4-IIAY PLUG CHARGE COIL TEST 9 5-60 IGNITION SPARK COil KEY 3-WAY TESTER SWITCH PlUG TEST If the neon tester is being used, turn the switch to position "2°. Depress load button "B" and at the same time crank the engine using the hand starter rope and observe the ligh t of the neon tester. If the neon light flashes, the charge coil is satisfactory for further service. If the neon light fails to flash, reverse the jumper leads of either tester and repeat the test. If the light fails to flash during either test, the charge coil MUST be replaced and the test repeated. After a new coil has been installed, the test should be successful. Test No. 10 Trigger Input This test is presented using a M-80 or S80 Tester. Insert a jumper wire between the "A" terminals of both parts of the four or five prong connector. Insert a jumper wire between the "D" terminals of the connector. SAFETY WORDS DO NOT touch the terminal ends of the jumper wires while making connections to the power pack, or when cranking the engine to prevent possible shock hazards. Attach one end of a jumper wire to the blue lead of the neon tester. Insert the other end of the jumper wire to terminal "B" in the power pack end of the connector. Connect one end of another jumper wire to the posi tive (+) side of the battery adapter. Insert the other end of the jumper wire into terminal "C0 in the power pack end of POWER 4-WAY SENSOR CHARGE PACK PlUG COil 10 the connector. Move the switch to position No. 3. Now, crank the engine with the hand starter rope, and tap the load button "8°. When the load button "B" is depressed, a spark should jump at the gap of the spark tester connected to the No. 2 ignition coil only. If spark is visible at both gaps of the spark tester during this test, replace the power pack. Reverse the jumper wires on terminals "Bn and "C" in the power pack end of the connector. Repeat the test to fire No. 1 ignition coil. If a spark occurred during each of these tests, the sensor coil is defective and must be replaced. If there was no spark, or a spark occurred on one of the tests, but not on the other, continue with the troubleshooting procedures. Remove the jumper wires. Carefully align the connector halves and assemble the connector. Just a drop of acetone or denatured alcohol on the prongs will act as a lubricant and ease assembly of the connector. Test No. 11 Power Pack Output This test is presented using a M-80 or S80 Tester. Separa te the three or five prong connector between the power pack and the ignition coils. Connect each end of a jumper wire to the "C" terminal of the male and female halves of the connector. TYPE II CD WITH SENSOR COIL 5-61 TEST 11 Connect the blue lead of the neon tester to a good ground on the engine. Connect one end of another jumper wire to the black lead of the tester. Insert the other end of the jumper wire to terminal "B" in the power pack end of the connector. Set the neon tester switch to position No. l. Now, hold load bu tton "A" depressed, and at the same time crank the engine with the hand starter rope, and observe the ligh t in the tester. Reverse the jumper wires between terminals ''B" and "C" in the power pack end of the connector. Hold the load bu tton "A" depressed and at the same time crank the engine with the starter rope and again observe the light in the tester. If the neon light flashes on each output test, the power is satisfactory. Check the ignition coils. If the neon light does not flash, or flashes on only during one of the tests, replace the power pack and repeat this power pack output test. Power Pack Output Using Neon Test Light Connect one lead of the tester to either the ''B" or "C" terminals of the power pack end of the connector. Connect the other lead to a good ground on the engine. Crank the engine with the starter rope and observe the light. If the light flashes during both tests, the power is in good condition. If the light flashes during only one test or does not flash at all, the power pack is unfit for further service and must be replaced. Remove all jumper wires and test equipment. Assemble the connec tor. Test No. 12 Ignition System Using CD Voltmeter Tester This is a special tester available only through OMC. These test can only be performed using this piece of equipment. SENSOR CHARGE CO il TEST 12 BEFORE conducting the following test, the Spark Test, Stop Button Test, and the Ohmmeter Tests should have been performed. Checking for Shorts to Ground Set the meter switches to Negative and 500. Disconnect the four or five prong connec tor. Insert the red meter lead into the "A" cavity of the female half. Connect the black meter lead to the armature plate or to a good ground on the engine. Crank the engine with the hand starter rope and observe the meter reading. Remove the meter lead from the "A" cavity and insert it into cavity "D", same half of the connector. Again, crank the engine with the starter rope and observe the meter. ANY meter reading during EITHER test indicates the charge coil is shorted to 'i>..s G) 500 POWER It-WAY SENSOR CHARGE PACK PLUG CO IL TEST 13 5-62 IGNITION ground. Check it out. Find the short and repair it, or replace the charge coil. Test No. l3 Charge Coil Outpu t Set the meter switches to Negative and 500. Insert the red meter lead into the "D" cavity of the female part of the connector. Insert the black meter lead into the "A" cavity. Crank the engine and observe the meter reading. If the meter reading is less than 230, replace the charge coil. If the meter reading is 230 or higher, proceed with the Sensor Coil Ou tpu t Test in the following paragraphs. Test No. Ill Sensor Coil Test for Short to Ground Set the meter switches to "S0 and "5°. Disconnect the four or five prong connector. Insert the red meter lead into the "C" cavi ty of the female part of the connector. Connect the black meter lead to the armature pia te or to a good ground on the engine. Crank the engine with the hand starter rope and observe the meter reading. Remove the lead from the "C' cavity and insert it into the "B" cavity. Again, crank the engine and observe the meter reading. ANY reading during EITHER test indicates the sensor coil is shorted to ground. Check it out. Find the short and repair it, or replace the sensor coil. Test No. 15 "C0 CHARGE CO IL Sensor Coil Output Test Set the meter swi tches to "S" and "5". Insert the black tester lead into the ..@s Q)500 POWER 4-WAY SENSOR PACK PlUG TEST 14 cavity of the female part of the connector. Insert the red meter lead into the "B" cavity. Crank the engine with the hand starter rope and observe the meter reading. If the meter reading is less than 0.3, replace the sensor coil. If the meter reading is 0.3 or higher, proceed to the Power Pack Output Test. Assemble the four or five prong connector. SPECIAL WORDS If testing a unit with a five prong connector, proceed to Test No. 18. Test No. 16 Power Pack Output Test Units with three prong connector: Set the meter switches to NEGATIVE and 500. Disconnec t the three-prong connector between the power pack and the ignition coils. Insert jumper leads between the "B" and "C" terminals of both maie and female halves of the connector --"B" to "B" and "C" to "C". Connect the black meter lead to a good ground on the engine. Connec t the red meter lead to the metal part of the jumper lead coming from the power pack cavity "B" --the female connec tor. Crank the engine and observe the meter reading. Now, connect the red meter lead to the metal part of the jumper lead in the "C" cavity. Again, crank the engine. The meter reading should be 180 or higher. es vith key, choke, and "hot horn" incorporated. To start the engine, the control lever moved to the NEUTRAL position and the warmup lever to the START position. After engine has started and allowed to warm to normal operating temperature, the warmup lever should be moved to the RUN position. A lockout knob is installed under the control lever handle. This knob MUST be depressed to permit the control lever to move to the FORWARD or to the REVERSE position. The control lever handle must be moved approximately 45° of its total travel for complete shift movement in the lower unit. If the control handle is moved oast the ' ° 45 point, the throttle is advanced and engine speed increases. A throttle friction adjustment knob installed on the front of the control box can be adjusted to permit the operator to release his grasp on the handle viithout the throttle "creeping" and thus changing engine speed. The friction knob should be adjusted only to the point to prevent the throttle from "creeping". TROUBLESHOOTING The following paragraphs provide a logical sequence of tests, checks, and adjustments, designed to isolate and correct a problem in the shift box operation. The procedures and suggestions are keyed by number to matching numbered Throttle and shift side lever. This linkage should be checked for corrosion and freedom of rr.ovement. SINGLE-LEVER REMOTE CONTROL 7-2 1 illustrations as an aid in performing the work. The single-lever remote control shift boxes are fairly simple in construction and operation. Seldom do they fail problems requiring service in addition normal lubrication. Hard Shifting or Difficult Throttle Advance Checking Throttle Side Remove the throttle and shift control at the engine. Now, at the shift box, attempt to move the throttle or shift lever. If the lever moves smoothly, without difficulty, the problem is immediately isolated to the engine. The problem may be in the tower shaft between the connector of the throttle and the armature plate. The armature plate may be "frozen", unable to move properly. On the late model units, the "lever aclvance arm" located on the starboard side of the engine may be "frozen" and reouire disas sembly and lubrica.tiono If the problem with shifting is at the engine, the first place to check is the area where the shift lever extends through the exhaust housing. The bushing may be worn or corroded. If the bushing requires re placement, the engine power head must be removed. Another cause of hard shifting is water entering the lower unit. In this case the lower unit must be disassembled, see Chapter 8. If hard shifting is still encountered at the shift box when the controls are discon nected from the engine, one of two areas may be causing the problem: the ca.bles may be corroded and require replacment; or, the teeth on the plastic shift lever assembly in the shift box may be worn or broken. This is a common area for oroblems. CASING GUIDE Cut-a-way view of the cable passing through the casing guide. Note the crimp made by the clamp screw. The anchor screw is brought up just tight, as described in the text. 7-22 REMOTE CONTROLS Unable to Obtain Full Shift Movement or Full Throttle Normally, this type of problem is the result of improper shift box installation. This area includes connection of the shift and throttle cables in the shift box. If the stainless steel inner wire was not heated and the clamp did not hold the inner cable (wire), the wire could slip inside the sleeve and the cable would be shortened. Therefore, if it is not possible to obtain full shift or full throttle, the shift box must be removed, opened, and checked for proper installation work. The inner wire could also slip at the engine end of the control, but problems at that end are very rare. Usually if improper installation work has been done at the engine end, the ability to shift at all is lost, or the throttle cannot be actuated. If the lower unit has previously been removed, the shift rod may not have been adjusted properly. DISASSEMBLING Throttle Cable and Shift Cable Preparation Tasks: Disconnect the leads at the battery terminals and disconnect the spark plug wires at the plugs, as a safety precaution to prevent possible personal injury during the work. A professional mechanic can usually service the cables, including replacement, without removinj?; the box from the side of the boat. However, the job is made much easier if the box is removed and laic! on its side on the boat seat. 1-Use the proper size Allen wrench and remove the screw from the center of the throttle and shift handle. It is not necessary to remove the shift handle, however the work will progress easier if the handle is rerr;oved and out of the way. 2-Remove the three Phillips screws on the bottom, the side9 or both ends of the panel on the lower section of the shift box. Observe inside the box and notice the attaching screws securing the box to the side of the boat. Remove the screws and lay tbe shift box on the boat seat. 3-Lift the electrical cable aPd grommet up out of the slot at the rear of the shift box. Loosen the anchor screv.1s on the end of the casing guides. On the back side of the shift box two holes are ;provided to permit inserting an Allen wrench to hold the underneath scre\v while the upper outside Allen screws are removed. After the screws Back side of the shift box sho·wing the two access holes through which an Allen wrench rl"ay be passed to loosen the inner cable retaining screv,s. BACK SIDE CLAMP SCREW CAS ING GU IDE SH IFT WIRE ' BACK SIDE CLAMP SCREW CAS ING GU IDE SH IFT WIRE ' have been loosened, pull the shift cable out of the cable casing. 4-To remove the cables at the engine end: Remove the self-locking nuts securing the cables to the engine. Remove the clip on the trunnion. Slip the end of the cable out of the engine retainer, and then remove the cable from the boat. To remove the guide casings at the engine end: Loosen the Allen screws on both sides and pull the casing free. Throttle Cable Lubrication If the throttle cable is NOT to be replaced, now is an excellent time to lubricate the inner wire. 5-To lubricate the inner wire, remove the casing guide from the cable at both ends. Attach an electric drill to one end of the wire. Momentarily turn the drill on and off to rotate the wire and at the same time allow lubricant to flow into the cable, as shown. ASSEMBLING Shift or Throttle Cable Into Shift Box The following procedures are to be followed to install either the shift cable or the throttle cable. CRITICAL WORDS Check the end of the cable to determine if the temper has been removed. If the end has a bluish appearance, it has been heated at an earlier date and the temper removed. The temper MUST be removed to permit the holding screw to make a crimp in the wire SINGLE-LEVER REMOTE CONTROL 7-23 THROTTLE CABLE to hold an adjustment. If the wire has not been tempered, heat the end, but not enough to melt the wire" It is very easy to shear the wire by applying EXCESSIVE force when tigh tening the screw to make the crimp. Therefore, play it cool. Tighten the screw; make one more complete turn to make the crimp; call it good; and then bring the other screw up just tight against the wire. 1-Place the shift control handle in the NEUTRAL position and the warmup lever in the START position. Coat the cable sleeve with anti-corrosive lubricant, and then slide the casing guide over the cable end. Thread one screw in to the control cable clamp. Insert the casing guide into the shift control clevis and align the hole in the casing guide with the hole in the clevis. Lubricate and insert control wire clamp in the clevis hole with the screw toward the back of the control lever. Align the wire holes in the clamp with wire holes in the casing guide. Feed the control wire through the clamp until the wire is flush to within 1/32" (0.8 mm) recessed with the end of the casing. Secure the 7-24 REMOTE CONTROLS BACK SIDE CLAMP SCREW CD cable wire in the casing guide. The control wire is held in place with two screws --the clamp screw already in place and the anchor screw. The wire MUST be crimped as described in "Critical Words'' at the beginning of these Ass<:>mbling procedures to hold the adjustment. This is accomplished by reaching through the access hole in the rear of the control box with a 3/32" Allen wrench and tightening the screw until it is up just snug against the wire. Now, tighten the screw ONLY one complete turn more to make the crimp. Install the second screw, from the front and bring it up just tight against the wire. The wire will now be held securely in the casing guide. SPECIAL NOTE The previous procedure is complete to install either the throttle or the shift cable. If both cables are to be replaced, the complete procedure must be followed again to install the second cable properly. CLAMP CAS ING SCRE GU IDE WIRE ANCHOR CLIP SCREW Cut-a-way section of the throttle or shift cable connection at the shift bo:x. Note the crimp in the wire made by the clamp screw. The anchor screw is brought up just tight as explained in the text. 2-Snap the nylon trunnion caps onto the cable trunnion, and then position the trunnion in the remote control. If the cable has a spherical trunnion, use the anchor blocks included with 'the new cable instead of the nylon trunnion caps furnished with the remote control. The nylon caps may be discarded. 3-Insert the electric cable p,rommet into the remote control. 4-l\;1ount the shift control box in the boat and secure it in place vvith the attaching screws. Install the shift control handle. Back side of the shift bo:x showing the two access holes through which an Allen wrench may be passed to tighten tr.e inner cable retaining screws. SINGLE-LEVER REMOTE CONTROL 7-25 Install the access cover with the throttle cable positioned in the machined recess in the cover and the nylon trunnion caps in place. Clamp the control cables to the boat along the run to the engine. Shift or Throttle Cable at the Engine 5-Check to be sure the shift control lever is in the NEUTRAL posi tion and the warmup lever is in the RUN position. Insert the clamp in the casing guide. Start the Allen screws into the clamp. Work the casing guide down over the cable (shift or throttle cable), until the wire protrudes out into the inspection hole of the guide. CRITICAL WORD The flat side of the casing guide MUST face toward the engine. This flat side is necessary to allow the guide to move as the throttle or shift lever is operated. Tighten one of the Allen screws until it makes contact with the wire, and then give it ONLY one more complete turn to make the crimp in the wire. Tighten the other Allen screw just snug against the wire. CAS ING CLAMP GU IDE SCREW CONTROL VIRE The previous procedure is complete to install either the throttle or the shift cable cable at the engine. If both cables are to be replaced, the complete procedure must be followed again to install the second. cable properly. 6-Place the shift or throttle cable onto the shift or throttle lever studs. Secure the cables in place with the washers and locknuts. 7-IV.ove the throttle lever on the engine until the idle stop screw makes contact with the stop. Pull firmly on the throttle casing guide and trunnion nut to remove any back.::. lash in the cable run and at the remote control at the shift box. If this backlash is not removed, the engine may not return to a consistent idle speed. 0-RING 7-26 REMOTE CONTROLS 8-Adjust the trunnion adjustment nut on the throttle cable until the cable will slip into the trunnion. Install the throttle or shift cable into the trunnion and install the retaining cover over the top of the trunnion and tigh ten the screw in the center of the trunnion. SHIFT BOX REPAIR SAFETY WORD Always disconnect the electrical leads at the battery terminals to prevent possible personal injury during the work. 1-Remove the throttle and shift handle by first removing the Allen screw in the center of the handle. 2-Remove the three Phillips screws on the lower side of the shift box, and then remove the cover. 3-Remove the screws from the top of the shift box, and then the arm rest. Remove the two screws from the back side of the shift box securing the upper panel to the outside of the shift box, and then lift off the panel. 4-Remove the screws from the inside of the shift box securing the shift box to the boat. Use an Allen wrench and working from the back sicle and another Allen wrench from the front side, remove the Allen screws in the control v.1ire on the end of the casing guideo Remove these screws from the shift and the throttle 'Nires. GOOD WORDS As the panel is lifted, notice how the arm and the mechanism for the throttle are mounted on one side of the panel. Notice the key switch, overheat horn, cam, and start-in-neutral switch installed on the other side of the panet Also observe the spring and ball bearing under the plate installed under the shift cam. SINGLE-LEVER REMOTE CONTOL 7-27 Worn (left) anc' new (rirht) shift levers. Note the worn teeth indicating this lever is no longer fit for service. Pay special a.ttention to the shift lever teeth. The teeth are made of a hard plastic material. V/om teeth will result in hard shifting. ASSEMBLING GOOD WORDS During the assembling \Vork, take time to coat the friction areas of mechanical movinp parts with OMC Multi-purpose grease. 1-Slide the bushing onto the shift lever post in the housing, and then install the lever with the countersunk side of the washer facing UP. Tighten the screw to the specifications p;iven in the Appendix. Before installing the shift lever, the detent spring and ball must be removed from the retainer. 2-Lower the shift lever down over the 5-Lift the cam assembly from the panel. TAKE CARE not to lose the spring and ball bearing installed under the plate. 6-Remove the countersunk screw, flat washer, shift lever, and bushing from the housing. Remove the screw and cover plate containing the spring and ball bearing on the right side of the shift box. CLEANING AND INSPECTING Disassemble and clean mechanical parts in solvent, and then blow them clry with compressed air. NEVER dip electrical parts in solvent. Check wirinp: and electrical parts for continuity wtih a test light or an ohnrmeter. Faulty electrical parts MUST be replaced. · Inspect mechanical parts for wear, cracks, or other damage. Questionable parts should be replaced to ensure satisfactory service. DETENT 'BALL AND SPRING "" '.. .. , .. shift cam with the center tooth of the shift lever indexes with the center tooth on the cam. 3-Install the ball and detent spring into the recess, and then install the cover over the spring. 7-28 REMOTE CONTROLS 4-Place the top cover on the inner shift box with the lever cam follower seating in the shift lever cam channel. Tighten the screws on the back side of the shift box. 5-Install the arm rest to the top of the shift box and secure it in place with the re taining screws. 6-Slide the throttle and shift cables into the shift box and attach the casing guides in the shif t and throttle levers. Tigh ten the Allen screws from the rear and side of the box. If difficulty is encountered during installation of the cables, see the more de tailed instructions under Shift Cable Installation earlier in this section. Install the shift box to the side of the boat. Check to be sure the cables are in their trunnions and the wiring harness is in the recess. Install the lower cover, and then install the shift handle and secure it with the Allen screw. Shift lever and shift cam illustrating how the teeth of each indexes with the teeth of the other. 7-8 CABLE END FITTING INSTALLATION AT THE ENGINE END FOR ALL SHIFT BOXES EXCEPT SINGLE LEVER REMOTE CONTROL GOOD WORDS The procedures outlined in this section apply to the installation of the cable end fitting at the engine for all shift box installa tions. MORE GOOD WORDS The anchor on the engine, to which the trunnion is attached, has a "P" and an "S" stamped on the inside diameter or inside edge of the trunnion retainers. These letters identified PORT and STARBOARD. INSTALLATION Shift Cable End I-Move the con trol lever at the shift control box to the NEUTRAL position. Slide the gear shift fitting onto the control wire. Check to be sure the inner wire passes completely through the small holes in the cable clamp. Clamp the anchor screws to prevent twisting the cable. The clamp and the anchor screws MUST be parallel to the trunnion on the gear shift cable. 2-Notice the flat and rounded areas of the casing guide. The flat edge MUST face TOWARD the engine. In this position, there is a flat area for the lever to ride during the shifting action. After the cable is in place in the casing guide, tighten the top screw until a definite crimp is made in the cable. If the screw is not tightened enough, the inner wire will slip during operation and the adjustment will be lost. CRITICAL WORDS Check the end of the cable to determine Trunion cap and tension clip. The tension clip must be installed to hold the proper adjustrr.. ent. CABLE END FITTING 7-29 CASING GUIDE ' ANCHOR SCREW CD LOCKING PLUG CABLE CLAMP ....,........,. SHIFT LEVER HOLE ADJUSTING NUT 0 if the temper has been removed. If the end has a bluish appearance, it has been heated at an earlier date and the temper removed. The temper MUST be removed to permit the holding screw to make a crimp in the wire to hold an adjustment. If the wire has not been tempered, heat the end, but not enough to melt the wire. Bring the second screw up tight against the wire. 3-Insert the shift cable control vertically into the trunnion bracket and turn the cable to a horizon tal position, as indica ted by the arrows in the accompanying illustration. TRUNN ION -0 7-30 REMOTE CONTROLS 4-Attach the shift cable end to the shift lever on the engine by inserting the fitting into the shift control lever, and then pushing inward, and at the same time rota ting the fitting 1/2-turn. This action will lock the fitting in the shift lever. Throttle Cable End Installation .5-Install the throttle lock pin spring over the casing guide. Start the screws into the small cylinder, and then slide the cylinder down through the pin spring and into the casing guide. Notice how the cylinder has a hole. This hole should be positioned vertically with the casing to align · with the hole in the guide. Slide the casing guide down over the throttle cable and insert the end of the wire through the sleeve. Tigh ten the top screw until a definite crimp is made in the wire. CRITICAL WORDS Check the end of the cable to determine i.f the temper has been re!T'ovec'. If the end has a. bluish appearance.. it has been heated at an earlier date and the temper removed. The temper MUST be removed to permit the holding screw to make a. crimp in the 'JI'ire to hold an adjustment. If the screv; is not tightened to this degree, the wire will slip during operation and the adjustment will be LONG CABLE CLAMP LONG CLAMP SCREW LUBR I CATE BRASS SLEEVE BEFORE ASSEMBLY 0-RING SEAL I CL IP LONG ANCHOR SCREW TRUNN ION lost. If the wire has not been tempered, heat the end, but not enough to melt the wire. Bring the bottom screw up tight against the wire. 6-Install the trunnion retainers to the engine, if necessary. Check to be sure the retainer with "P" stamped on the inside is installed on the PORT side of the engine and the retainer with the "S" installed on the STARBOARD side. Connect the trunnion cap to the trunnion retainer. This is accomplished by holding the trunnion in a vertical posi tion; inserting it into the retainer; and then turning it to the horizontal position, as shown. 7-Slide the guide over the pin onto the engine, and then snap the retainer clip over the end of the guide to lock it in place. Cable Adjustments See Chapter &, Lower Unit, to properly adjust the shift cable and to adjust the throttle cable. THROTTLE CABLE I \ (j) 8 LOWER UN IT 8-1 DESCRIPTION The lower unit is considered as that part of the outboard below the exhaust housing. The unit con tains the propeller shaft, the driven and pinion gears, the driveshaft from the powerhead and the water pump. On models equipped with shifting capabilities, the forward and reverse gears, together with the dutch, shift assembly, and related linkage, are all housed within the lower unit. The lower unit is removed by one of six methods depending on the model year and the engine horsepower. 1-The lower unit does not have shifting capabilities, therefore, removal of the lower unit is not an involved procedure. 2-The lower unit has shifting capabilities. The upper end of the shift rod indexes into the shift handle gear and the lower end of the rod indexes into the gear in the lower unit. Shift rod (left) and driveshaft (right) after the lower W1it has been separated from the exhaust housing. The flat on the shift rod must face in the direction shown toward the starboard side when the W1it is in forward gear. 3-The lower unit is lowered a couple inches and the shift connector removed. IJ-A window in the exhaust housing is opened and the shift connector disconnected. 5-A window in the lower unit is opened to disconnect the shift rod. 6-Green and blue shift wires are disconnected on the port side of the engine. Disconnecting the shift connector after the lower Lower W1it used on the 2 hp to 4 hp engines. The unit has been separated slightly from the exhaust shear pin is installed after the propeller is in place. housing. 8-2 LO\IVER UNIT 7-The shift rod is disconnected at the linkage under and to the rear of the bottom carburetor. The engine and model year is given in each section heading. Therefore, the Table of Contents may be used to determine which set of procedures to follow for the engine being serviced. CHAPTER COVERAGE Nine different lower units are covered in this chapter with separate sections for each, as indicated: Section 8-4 -lower unit does not have - shift capabilities. Sec tion 8-5 -lower unit has shift cap - ability but there is no shift disconnec t, the upper end of the shift rod indexes into a part of the shift handle and the other end is sp lined to index in to the gear. Sections 8-7 and 8-8 --both lower units have a spli t lower cap and are very similar, except the type of bearings used differ. Therefore, separate procedures are required. Sec tions 8-9 and 8-10 both lower units have propeller exhaust and use a sliding clutch dog. A detent ball and spring are used to hold the unit in the neutral position. The shif t mechanism on the 9.9 hp and 15 hp models is forward of the forward gear. On the 35 hp model, the shift mechanism is just aft of the reverse gear. Sec tion 8-11 lower unit has propeller exhaust with electric shift. Two solenoids The two wires on the port side of the engine which must be disconnected before the lower unit is removed. are used to affect the shift. One solenoid is used for neutral, and both solenoids are activated for the shift into reverse gear. Section 8-12 --lower unit has propeller exhaust and mechanical shift with a hydraulic assist pump. Section 8-13 --lower unit has propeller exhaust and mechanical shift with a sliding clutch dog. Movement of the clutch dog is mechanical utilizing a shift cradle and shift lever. Each section is complete with detailed procedures. No troubleshooting directions are given for Sections 8-4 and 8-5. Section 8-6 contains detailed troubleshooting instructions for the lower units covered in Window removed from a lower unit to gain access to the shift connector, as explained in the text. The detailed drawing, upper left, illustrates the relationship Shift rod extending up through the exhaust housing. of the bolt to the shift rod. The disconnection is made under the carburetor. Sections 8-7 and 8-8. The lower units covered in Sections 8-9, 8-10, 8-12, and 813, each contain their own troubleshooting procedures. Check the Table of Contents and follow the procedures in the given section for the unit being serviced. Water Pump Water pump service work is by far the most common reason for removal of the lower unit. Each lower unit service section contains complete detailed procedures to rebuild the water pump. The instructions given to prepare for the water pump work must be performed as listed. However, once the pump is ready for installation, if no other work is to be performed on the lower unit, the reader may jump to the pump assembling procedures and proceed with installation of the water pump. Each section is presented with complete detailed instructions for removal, disassembly, cleaning and inspecting, assembling, adjusting, and installation of only one type unit. ILLUSTRATIONS Because this chapter covers such a wide range of models over an extended period of time, the illustrations included with the Typical water pump installation on the 4.5 hp and 7.5 hp engine. PROPELLER SERVICE 8-3 procedural steps are those of the most popular lower units. In some cases, the unit being serviced may not appear to be identical with the unit illustrated. However, the step-by-step work sequence will be valid in all cases. If there is a special procedure for a unique lower unit, the differences will be clearly indicated in the step. SPECIAL WORDS All threaded parts are right-hand unless otherwise indicated. If there is any water in the lower unit or metal particles are discovered in the gear lubricant, the lower unit should be completely disassembled, cleaned, and inspected. Actually, problems in the lower unit can be classified into three broad areas: 1-Lack of proper lubrication in the lower unit. Most often this is caused by failure of the operator to check the gear oil level frequently and to add lubricant when required. 2-A faulty seal allowing water to enter the lower unit. Water allowed to remain in the lower unit over a period of non-use time will separate from the oil and can be destructive. 3-Excessive clutch dog and clutch ear wear on the forward and reverse gears. This condition is caused by excessive wear in the bellcrank under the powerhead. A worn bellcrank will result in sloppy shifting of the lower unit and cause the clutch components to wear and develop shifting problems. Improper shifting techniques at the shift box will also result in excessive wear to the clutch dog and clutch ears of the forward and reverse gears. Time will also take its toll. Continued service over a long period of time will cause parts to wear and require replacement. 8-2 PROPELLER SERVICE PROPELLER WITH SHEAR PIN REMOVAL If the unit being serviced has the shear pin located between the propeller nut and the propeller, the propeller nut should be removed and the shear pin checked. To remove the propeller, first pull the cotter key, and then remove the propeller nut, shear pin, and washer. Because the shear pin is not a tight fit, the propeller is 8-4 LOWER UNIT Arrangement of the shear pin, washer, and propeller nut on a typical lower unit. In this case, the shear pin is installed behind the propeller nut. able to move on the pin and cause burrs on the hole. The propeller may be difficult to remove because of these burrs. To overcome this problem, the propeller hub has two grooves running the full length of the hub. Hold the shaft from turning, and then rotate the propeller 1/4 turn to position the grooves over the drive pin holes. The propeller can then be pulled straight off the shaft. After the propeller has been removed, file the drive pin holes on both sides of the shaft to remove the burrs. If the propeller is the type with the shear pin installed next to the gearcase head, first remove the cotter key, then the propeller nut. Next, slide the propeller free of the shaft. Cross-section drawing of the lower unit showing route of the exhaust gases with the unit in forward gear (top), and in reverse gear (bottom). EXHAUST PROPELLER Propellers with the exhaust passing through the hub MUST be removed more frequently than the standard propeller. Removal after each weekend use or outing is not considered excessive. These propellers do not have a shear pin. The shaft and propeller have splines which MUST be coated with an anti-corrosion lubricant prior to installation as an aid to removal the next time the propeller is pulled. Even with the lubricant applied to the shaft splines, the propeller may be difficult to remove. Propeller with the two grooves through the center Propeller with exhaust hub. The defuser ring is to assist in removal from the shaft. clearly visible. The propeller with the exhaust hub is more expensive than the standard propeller and therefore, the cost of rebuilding the unit, if the hub is damaged, is justified. A replaceable diffuser ring on the backside of the propeller disperses the exhaust away from the propeller blades as the boat moves through the water. If the ring becomes broken or damaged "ventilation" would be created pulling the exhaust gases back into the negative pressure area behind the propeller. This condition would create considerable air bubbles and reduce the effectiveness of the propeller. PROPELLER WITH EXHAUST -REMOVAL First, disconnect the high tension leads to the spark plugs to prevent accidental engine start. Next, pull the cotter pin from the propeller nut. Wedge a piece of wood between one of the propeller blades and the cavitation plate to prevent the propeller from rotating. Back off the castellated propeller nut and remove the splined washer. Pull the propeller straight off the shaft. It may be necessary to carefully tap on the front side of the propeller with a soft headed mallet to jar it loose. Remove the thrust washer from the propeller shaft. "Frozen" Propeller If the propeller appears to be "frozen" to the shaft, see Section 8-14 for special removal instructions. The thrust washer Propeller exhaust arrangement showing the thrust washer, propeller, splined washer, and propeller nut. PROPELLER INSTALLATION 8-5 does not have to be removed unless it appears damaged. PROPELLER INSTALLATION WITH SHEAR PIN A FEW GOOD WORDS The propeller washer, if used, and shear pin, play an extremely important role. When shifting gears during normal operation, or if the propeller should hit an underwater obstacle, the propeller is subjected to considerable shock. A washer is installed between the propeller and drive pin. This washer MUST always be in place for proper operation. If the hub should slip, the propeller will move back towards the propeller nut and lock against the drive pin. The washer is designed to stop propeller movement so the drive pin can be easily removed for service. Now, on with the installation. Install the propeller. Coat the propeller shaft with an anti-corrosion grease. Install the propeller with the drive pin holes aligned. Install the washer and drive pin. Slide the propeller cap into place and secure it with the cotter pin. If the unit being serviced uses the shear pin between the propeller and the bearing carrier, proceed as follows: Install the shear pin and then coat the propeller shaft with anti-corrosion grease; install the propeller; propeller nut; and then the cotter pin. Removing the shear pin from the propeller shaft. In this case, the shear pin is installed between the propeller and the gearcase head. 8-6 LOWER UNIT Arrangement of the shear pin, washer, and propeller nut on a typical lower unit. In this case, the shear pin is installed behind the propeller nut. EXHAUST PROPELLER INSTALLATION Slide the thrust washer onto the propeller sha.f t. Coat the propeller shaft with Perfect Seal No. 4, Triple Guard Grease, or similar good grade of lubricant to prevent the propeller from becoming "frozen" to the shaft. Slide the propeller onto the shaft with the splines in the propeller indexing with the splines on the shaft. Slide the splined washer onto the shaft. Thread the castellated nut onto the shaft. Jamb a piece of board between one of the propeller blades and the cavitation plate to prevent the propeller from turning. Tighten the propeller nut securely and then a bit more to align the hole through the nut with the hole through the propeller shaft. Install the cotter pin through the nut and propeller shaft. Applying gasket sealer to the propeller shaft splines to prevent the propeller from becoming "frozen" to the shaft. Installing the thrust washer onto the propeller shaft Installation of a propeller exhaust propeller with of a propeller exhaust unit. principle parts identified. LUBRICATION 8-7 Tightening the nut on a propeller exhaust unit. The cotter pin is installed after the nut is secure. 8-3 LOWER UNIT LUBRICATION DRAINING LOWER UNIT Position a suitable container under the lower unit, and then remove the FILL screw and the VENT screw. CRITICAL WORD On many lower units, the Phillips screw securing the shift fork in place is located very close to the vent screw. On some units the Phillips screw is located on the other side. If the wrong screw is removed, BAD NEWS, VERY BAD NEWS. The lower unit will have to be disassembled in order to return the shift fork to its proper location, illustration A. Allow the gear lubricant to drain into the container. As the lubricant drains, catch some with your fingers, from time-totime, and rub it between your thumb and finger to determine if any metal particles are present. If metal is detected in the lubricant, the unit must be completely disassembled, inspected, and the damaged parts replaced, illustration B. Installing the cotter pin through the castellated nut on a propeller exhaust unit. 8-8 LOWER UNIT Check the color of the lubricant as it drains. A whitish or creamy color indicates the presence of water in the lubricant. Check the drain pan for signs of water separation from the lubricant. The presence of any water in the gear lubricant is BAD NEWS. The unit must be completely disassembled, inspected, the cause of the problem determined, and then corrected. FILLING LOWER UNIT Fill the lower unit with lubricant. Insert the lubricant tube into the bottom opening, and then fill the unit until lubricant is visible at the vent hole. The 2 hp model does not have a vent screw. Therefore, this unit must be laid in a horizontal position for filling and time taken to allow the lubricant to work into the lower unit cavity by raising the skeg slightly from time-to-time. Install the vent plug. Remove the gear lubricant tube and install the drain/fill plug. After the lower plug has been installed, remove the vent plug again and using a squirt-type oil can, add lubricant through this vent hole. A squirt-type oil can must be used to allow the trapped air in the lower unit to escape at the same time the final lubricant is added. Once the unit is completely full, install and tighten the vent plug. "Topping off" the lower W1it using a squirt-type oil can through the vent hole, as described in the text. 8-4 NO SHIFT LOWER UNIT SERVICE ALL 1.25 HP TO 4.0 HP EXCEPT 4 DELUX (4 Delux -See Section 8-5) Description This is a very simple direct drive unlt without any shift capabilities. Reverse is ° obtained by rotating the engine 180 and holding that position while the boat is moved stern ward. Therefore, no shift rod disconnec ts are necessary. Filling a lower W1it with OMC Gearcase Lubricant. Notice the vent plug has been removed to allow air to Installing a propeller onto a 2 hp to 4 hp W1it. The escape, as the W1it fills with lubricant. propeller, propeller nut, and cotter pin, are shown. NO SHIFT 8-9 TROUBLESHOOTING The first item to check whenever loss of boat movement is encountered is the shear pin. The next area to check is the rubber hub in the propeller, if one is installed. A worn hub will give an indication the unit is not in gear. The splines in the crankshaft or on the driveshaft may be damaged or worn and thus prevent rotation from the crankshaft to reach the propeller shaft. If the splines in the crankshaft are destroyed, the crankshaft will have to be replaced. See Chapter 3, Power head. If the splines on the dr iveshaft have been destroyed, the driveshaft must be replaced. Procedure to replace the driveshaft are included in each section of this chapter. Frozen Powerhead This condition is suggested when the operator unsuccessfully attempts to crank the engine with a hand starter. The flywheel will not rotate. Do not assume the engine is "frozen" until the lower unit has been removed and thoroughly checked. If the lower unit is "locked" (the driveshaft or propeller shaft will not rotate), the powerhead will have the indication of being "frozen" (failure to rotate the flywheel). · The first step to perform under these conditions is to "pull" the lower unit, and then again attempt to crank the engine. If the attempt is successful with the lower lower unit. If the attempt to crank the engine is still unsuccessful, the problem is in the powerhead. Propeller Removal Remove the propeller according to the procedures outlined in Section 8-2. Draining the Lower Unit Drain the lower unit according to the procedures outlined in Section 8-3. GOOD WORDS If water is discovered in the lower unit and the propeller shaft seal is damaged and requires replacement, the lower unit does NOT have to be removed in order to accomplish the work. The seal may be replaced by first removing the two screws securing the cap in place and then tapping on the cap with a softheaded mallet to jar it loose. The cap is then removed, the seal removed and replaced, and the cap installed and secured. LOWER UNIT REMOVAL ADVICE If the only work to be performed is service of the water pump, be extremely CAREFUL to prevent the driveshaft from being pulled up and free of the pinion gear in the lower unit. NEVER carry the lower unit by the driveshaft. If the shaft should be released from the pinion, the lower unit MUST be disassembled to align the pinion unit disconnected, the problem is in the gear and driveshaft, then the driveshaft installed. WATER PUHP 8-10 LOWER UNIT 1-Disconnect the spark plug wire from the plug. Remove the retaining bolts securing the lower unit to the exhaust housing. CAREFULLY pull directly downward, to prevent damage to the water tube, and remove the lower unit. WATER PUMP REMOVAL 2-Remove the screws securing the water pump to the lower unit housing. It is very possible corrosion will cause the screw heads to break-off when an attempt to remove the:n is made. If this should happen, use a chisel and break away the water pump housing from the lower unit. EXERCISE CARE not to damage the lower unit housing. 3-After the screws have been removed, slide the water pump and impeller upward and free of the driveshaft. Remove the Woodruff key, and then the lower water pump plate, GOOD WORDS The 2.5hp, 4hp, Ultra, Junior, and Excel units since 1984 have a water intake screen beneath the lower water pump plate. Remove the screen and clean away any debris which might clog the water passageway and cause an overhea ting condition. NOTE If the gear is pressed on to the propeller shaft. Therefore, the propeller shaft and gear are considered as a complete assembly. If either is damaged and requires replacement, the two are purchased as an assembly. On the 2.5hp, 4hp, Ultra, Junior, and Excel since 1984: Hold the forward gear sti!! while rotating the propeller shaft COUNTER-CLOCKWISE and pull the gear and shaft apart. Remove the spring. 5-Pull upward on the driveshaft, and at the sarne time, reach inside the lower unit and remove the pinion gear. Models 2.5hp, 4hp, Ultra, Junior, and Excel since 1 984 have a thrust washer and bearing set infront of the forward gear and another thrust washer and bearing set behind the pinion gear. remove and identify are instalh=·d In only work to be performed is service of the water pump, proceed direc tly to Water Pump Installation, Step 5 on Page 8-14. LOWER UNIT DISASSEMBLING 4-Remove the gearcase head and the two screws. Pull on the propeller shaf t or tap on the gearcase head to separate the gearcase head from the lower uni t housing. On all uni ts except the 2.5hp, 4hp, Ul tra, Junior, and Excel prior to 1984: The driven both se ts to make sure they their original loca tions. SPECIAL WORDS On the Weedless type lower uni t, a thrust bearing is installed under the pir.ion Exploded drawing of a non-shifting lower unit, with principle parts identified. gear. This thrust bearing can only be removed by tapping it out in the following manner: Turn the lower unit so the propeller shaft opening is facing downward. Now, gently rap the unit on a work bench or block of wood. The thrust bearing and pinion gear will be dislodged and fall free. 6-If the seal/s at the top of the lower unit housing under the water pump is to be replaced, remove the seal using any type seal remover. To remove the seal/s in the gearcase head, work the seal free by using a punch and mallet from the back side. Remove the 0-ring. CLEANING AND INSPECTING Clean all water pump parts with solvent, and then dry them with compressed air. Iospect the water pump cover and base for cracks and distortion, possibly caused from overheating. Inspect the face plate and water pump insert for grooves and/ or rough surfaces. If possible, ALWAYS install a complete new water pump while the lower unit is disassembled. A new impeller will ensure extended satisfactory service and give "peace of mind" to the owner. If the NO SHIFT 8-1 1 old impeller must be returned to service, NEVER install it in reverse to the original direction of rotation. In<>talla tion in reverse will cause premature impeller failure. Inspect the impeller side seal surfaces and the ends of the impeller blades for cracks, tears, and wear. Check for a glazed or mel ted appearance, caused from operating without sufficient water. If any question exists, and as previously stated, ins tall a new impeller if at all possible. NOTE : 8-12 LOWER UNIT DR I VESHAFT . PUMP/.. KEY GEAR CASE PROPELLER SHAFT AND GEAR PROPELLER HUB NUT H ..€) CLUTCH BUSHING PROPELLER . Exploded drawmg of the Weed!e" lower unit gear case, with ma. ]Or parts identl"f. led. NO SHIFT 8-13 Propeller used on the 2 hp to 4 hp unit with removeable hub. This hub is badly corroded. The hub and propeller should be replaced. Clean all parts with solvent and dry them with compressed air. DISCARD all 0rings and gaskets. Inspect and replace the dr iveshaft if the splines are worn. Inspect the gearcase and exhaust housing for damage to the machined surfaces. Remove any nicks and refurbish the surfaces on a surface plate. Start with a No. 120 Emery paper and finish with No. 180. Check the water intake screen and passages. Inspect the drive gear, pinion gear, and thrust washers. Replace these items if they appear worn. LOWER UNIT ASSEMBLING SPECIAL WORDS The 2.5hp, 4hp, Ultra, Junior, and Excel since 1984, use a double seal arrangement on the propeller shaft and driveshaft. The two seals are installed BACK-TO-BACK (flat side to flat side). The outer seal will prevent the water from entering the lower unit and the inner seal will prevent lubricant in the lower unit from escaping. 1-Tap a NEW seal/s into place on top of the lower unit housing. 2-Tap a NEW seal/s into place in the gearcase head. Install a NEW 0-ring into the groove in the gearcase. 3-On the 2.5hp, 4hp, Ultra, Junior, and Excel units since 1984: Place the thrust bearing followed by the thrust washer down over the flat surface of the pinion gear. All Models: Install the pinion gear into the recess in the lower unit housing. If the unit being serviced is the "Weedless" type gearcase, install the thrust bearing with the bosses on the bearing indexed between the two bosses in the gearcase. Hold the pinion Checking the drive gear and propeller shaft on a 2 hp lower unit. 8-14 LOWER UNIT gear in place with one hand and with the other hand install the driveshaft down into the lower unit. Continue to hold the pinion gear, and at the same time, rotate the dr iveshaft slightly after it makes con tact with the pinion gear to allow the splines on the shaft to index with the splines in the gear. SPECIAL WORDS After the driveshaft is installed, care must be exercised NOT to allow the driveshaft to slip out of position in the pinion gear. This is especially important during water pump installation work. If the driveshaft should come free, the lower unit must be disassembled in order to install the driveshaft back into the pinion gear. MORE SPECIAL WORDS If servicing a 2.5hp, 4hp, Ultra, Junior, or Excel manufactured since 1984: Slide the spring over the forward gear shank with the spring tang facing the gear. Push the propeller shaft into the gear shank while rotating the shaft COUNTERCLOCKWISE, until the shaft seats. Slide the thrust bearing followed by the thrust washer over the forward end of the shaft. All Models 4-Coat the propeller shaft and the gearcase 0-ring with oil as an aid to installation. Install the gearcase head over the propeller shaft. Slide the propeller shaft through the lower unit with the driven gear teeth indexed with the teeth of the pinion gear. It may be necessary to rotate the propeller shaft slightly in order to index the driven and pinion gear tee th. The teeth MUST engage fully and properly or the gearcase head will be damaged when the attaching screws are installed. Coat the screws securing the head to the lower unit with sealer, and then install the screws. CARE FULLY tap on the gearcase head with a sof t-headed mallet and tighten the screws EVENLY and ALTERNATELY. CRITICAL WORDS If the screws are not tightened evenly, or the driven gear and pinion gear teeth are not fully and properly engaged, the gearcase head will be thrown out of line just a whisker, and the ears through which the bolts pass may snap off. BAD NEWS! A new gearcase head would have to be purchased. If the unit being serviced is the "Weedless" type, two sets of matching marks on the gearcase head and the lower unit MUST be aligned when the head is installed. If the unit being serviced is the "HighThrust" type, the gearcase has a hole which MUST face upward when the head is installed. WATER PUMP INSTALLATION 5-Lay down a bead of sealer No. 1000 onto the lower unit surface. If servicing a 2.5hp, 4hp, Ul tra, Junior, or Excel unit manufactured since 1984: Install the water intake screen over the driveshaft with the three prongs facing UPWARD. All models: Slide the water pump plate down the dr iveshaft and on to the lower unit surface, or screen if used. 6-Insert the Woodruff key into the driveshaf t groove. · NO SHIFT 8-15 7-Slide the water pump impeller do·.vn the driveshaft and into place on top of the water pump base plate with the pump pin indexed in the impeller. Lubrica te the ir.side surface of the water pump with lightweight oil. 8-Lower the water pump housing down the dr iveshaft anc! over the impeller. Rotate the driveshaft CLOCKWISE as the water pump housing is lowered to allow the impeller blades to assume their natural and proper position inside the housing. Continue to rotate the driveshaft and work the water pump housing downward until it is seated on the lower unit upper housing surface. 9-Rotate the driveshaft CLOCKWISE while the screws are tigh tened to prevent damaging the impeller vanes. If the icnpeller is not ro ta ted, the housing could damage or cut the end of the vanes as the screws are brought up tigh t. The rotation allows them to spring ba.ck into a natural p·:>;ition. Place a NEW grommet into the water pump housing for t!"te water pickup tube. If a new water pump was installed, this seal will already be in place. Install a NEW 0-ring on the top of the driveshaf t. LOWER UNIT INSTALLATION 10-Clean and shine the water pump tube wi th lightweight sandpaper, and then coat it with oil as an aid to installation. Apply oil to the grommet in the water pump housing as a further aid to installation. This tube is very small in size and will bend easily during installation if it has even a little difficulty passing through the rubber grommet in the water pump housing. Bring the lower unit together to mate with the exhaust housing. Guide the water tube into the water pump housing grommet, and at the same time rotate the propeller shaft CLOCKWISE. Rotating the propeller 8-1 6 LOWER UNIT shaft will also rotate the driveshaft and allow the splines on the driveshaft to index with the splines of the engine crankshaft. Continue to work the lower unit closer to the exhaust housing until the mating surfaces make contact. Coat the retaining screws with sealer to prevent corrosion, and then start them in place. Tighten the retaining screws EVENLY and ALTERNATELY. FILLING THE LOWER UNIT 11-Fill the lower unit with lubricant. Insert the lubricant tube into the bottom opening, and then fill the unit until lubricant is visible at the vent hole. Install the vent plug. Remove the gear lubricant tube, and install the drain/fill plug. 12-After the lower plug has been installed, remove the vent plug again and using a squirt-type oil can, add lubricant through this vent hole. A squirt-type oil can must be used to allow the trapped air in the lower unit to escape at the same time the final lubricant is added. Once the unit is completely full, install and tighten the vent plug. PROPELLER INSTALLATION FIRST, THESE GOOD WORDS The propellers used on the outboards covered in this section have a removable clutch ring and a clutch hub, and bushing. Under normal conditions, these items are NOT removed from the propeller. However, if they have been removed for any number of reasons, they should be coated with OMC Type "A" lubricant prior to installation. The bushing is installed first, then the clutch hub, and finally the clutch ring, illustration A. 13-Install the shear pin. Apply a light coating of anti-corrosive lubricant onto the ® propeller shaft. Slide the propeller on to the shaft, then the washer, and finally the propeller nut, with the flange on the nut TO­WARDS the propeller. Tighten the nut securely. Install a cot ter pin to preven t the nut from backing out. Slip the rubber cap over the propeller nut. 14-Perform a functional check . of the completed work by mounting the engine in a test tank, in a body of water, or with a flush a ttachrnent connected to the lower unit. If the flush attachment is used, NEVER operate the engine above an idle speed, because the no-load condition on the propeller would allow the engine to RUNAWAY resulting in serious damage or destruction of the engine. CAUTION: Water must circulate through the lower unit to the engine any time the engine is run to prevent damage to the water pump in the lower mit. Just five seconds without water will damage the water pump. Start the engine and observe the tattletale flow of water from idle relief in the exhaust housing. The water pump installation work is verified. If a "Flushette" is connected to the lower unit, VERY LITTLE water will be visible from the idle relief port. SHIFT NO DISCONNECT 8-17 8-5 LOWER UNIT SERVICE SHIFT WITH NO DISCONNECT 4 DEL UX, 4.5HP, 5HP, 6HP, 7 .5HP, AND 8HP 1980 AND ON Description This unit has a shift mechanism that is controlled through a shift handle on the starboard side of the exhaust housing. A shaft extends through the housing and is connected to a gear on the inside. Another gear transfers the motion downward by means of a shaft indexed in to the gear. Therefore, the shift rod is not disconnected in order to remove the lower unit. The unit is shifted through a cam and plunger on the end of the shift rod. This cam and plunger arrangement forces the clutch dog forward and aft for NEUTRAL gear and REVERSE gear operation. The cam and plunger on the end of the shift rod are at rest when the unit is in FORWARD gear. Action takes place and movement is necessary to depress the pin in the propeller shaft to move the clutch dog for neutrc.l and reverse gear. Propeller Removal Remove the propeller according to the detailed procedures outlined in Section 8-2. 8-18 LOWER UNIT Draining the Lower Unit Drain the lower unit according to the procedures outlined in Section 8-3. LOWER UNIT REMOVAL ADVICE If the only work to be performed is service of the water pump, be extremely CAREFUL to prevent the driveshaft from being pulled up and free of the pinion gear in the lower unit. NEVER carry the lower unit by the driveshaft or by the shift rod. If the shaft should be released from the pinion, the lower unit MUST be disassembled to align the pinion gear and driveshaft, then the driveshaft installed. 1-Disconnect the spark plug wire from the plug. Turn the propeller shaft CLOCKWISE, and at the same time shift the unit into FORWARD gear using the shift handle. Remove the retaining bolts securing the lower unit to the exhaust housing. Two bolts are located under the caviatation plate on each side of the zinc. A third bolt is located just above the cavitation plate at the forward leading edge of the exhaust housing. CAREFULLY pull directly downward on the lower unit, to prevent damage to the water tube, driveshaft, or shift rod, and remove the lower unit. The shift rod and the driveshaft will come free of the powerhead with the lower unit. GOOD WORDS If this shift rod is frozen in the gear at the shift handle, the rod will not come free with the lower unit. In this case, the shift handle mechanism must be disassembled in order to remove the gear on the end of the shift rod. The powerhead would have to be removed to gain access to the gears. MORE GOOD WORDS In MOST cases, if any unit being serviced has the 6-inch extension, it is NOT necessary to remove the extension in order to "drop" the lower unit. 2-Position the lower unit in a vertical position on the edge of the work bench resting on the cavitation plate. Secure the lower unit in this position with a C-clamp. The lower unit will then be held firmly in a favorable position for further service work. An alternate method is to cut a groove in a short piece of 2" x 6" wood to accommodate the lower unit with the cavitation plate resting on top of the wood. Clamp the wood in a vise and service work may then be performed with the lower unit erect (in its normal position), or inverted (upside down). In both positions, the cavitation plate is the supporting surface. WATER PUMP DISASSEMBLING TAKE TIME Take time to notice the four bolts passing through the water pump. If a water pump replacement is the only work to be performed, DO NOT remove the three bolts in the gear case cover. If these bolts should mistakenly be removed, the shift rod will be dislodged BAD NEWS. It is then necessary to rebuild the lower unit. SHIFT NO DISCONNECT 8-19 .3-With the lower unit in position as described in Step 2 above, remove the ring from the top of the driveshaft. Remove the four bolts through the water pump. Work the water pump upward and free of the driveshaft. 4-Work the impeller up the driveshaft. Remove the impeller key. 5-Remove the water pump plate and gasket. Notice the plate and two gaskets under the water pump impeller. Notice how the plate is installed with the beveled, or rounded side of the plate facing UP. Both gaskets are identical and either one may be installed on top of the plate. If the only work to be performed is service of the water pump, proceed directly to Page 8-33, Water Pump Installation. LOWER UNIT DISASSEMBLING 6-Remove the two screws installed in the gearcase head. Tap the gearcase head in either direction with a soft-headed mallet, to turn the head in the housing. The ears of the gearcase head will then protrude out the side of the lower unit. After the ears are exposed, tap on the bottom side of the ears and remove the gearcase head. 7-After the head is removed, the reverse gear, propeller shaft, and clutch dog can then be removed as an assembly. As the shaft is removed, TAKE CARE not to lose the plunger from the center of the shaft. Slide the gearcase head and reverse gear from the propeller shaft. If working on a newer model, 1984 and on, also slide the thrust washer from the propeller shaft. 8-Remove the plunger pin from inside the propeller shaft end. Use a small screwdriver and work the coiled spring off the 8-20 LOWER UNIT inside diameter of the clutch dog. Be very careful not to stretch the spring out of shape. If the spring is distorted, it is unfit for further service, because it will not hold the pin properly in the clutch dog. Therefore, if the spring is stretched out of shape, it must be replaced. 9-Use special tool OMC No. 390766 to remove the pin from the clutch dog. Insert the tool into the forward gear end of the propeller shaft, push downward, and at the same time push the pin through the clutch dog. Ease up on the tool and remove the clutch dog from the propeller shaft. This special tool will depress the spring and allow the pin to be removed. 10-If the tool is not available, hold the end of the propeller shaft on the bench or piece of wood, press down on the shaft, remove the plunger pin. 11-Remove the spring from the end of the propeller shaf t. 12-Insert the propeller shaft down into the forward gear. Use a clenched fist and rap sharply on the end of the propeller shaft towards the cavitation plate. This action will diseneage the forward gear bearing out of the cup and from the pinion gear. Remove the propeller shaft. Reach into the lower unit and remove the forward gear. 13-Pull upward on the driveshaft, and at the same reach inside the lower unit and remove the pinion gear, the two thrust washers, and the thrust bearing. Notice how the washers are installed on the pinion gear. They MUST be installed in the same order and position from which they are removed. 14-Clean the shift rod and then coat it with oil, as an aid to removing the gearcase cover. Remove the three retaining bolts, - and then slide the gearcase cover up and free of the shift rod. 15-Lift the shift rod free of the gearcase, and at the same time reach into lower unit cavity and remove the shift cam. Removing the Forward Bearing Race 16-Use a slide hammer with fingers to remove the forward bearing race from the lower unit housing. GOOD WORDS A driveshaft bearing is installed at the top of the lower unit. A pinion gear bearing is installed at the lower end of the driveshaft. A bearing is attached to the forward gear. Under normal overhaul conditions, it is not necessary to remove these bearings unless they are unfit for further service. To determine if replacement is necessary, insert a finger into the bearing and feel for SHIFT NO DISCONNECT 8-2 1 Pinion gear with the beveled washers and thrust washer in the correct order on the shank. roughness. Check them with a flashlight. However, if they are to be removed, perform the following three steps. 8-22 LOWER UNIT Upper Gearcase Bearing Removal 17-A special puller is required to remove the upper bearing installed under the gear case cover. The complete puller consists of a slide hammer, OMC No. 380658, and a bearing remover, OMC No. 380657. If the special puller is not available, a puller similar to the one shown in the accompanying illustration may be used effectively. Fit the fingers of the puller underneath the bearing and hold them in place with a heavy rubberband. Use the slide hammer to pull the bearing free of the recess. The slide hammer in this case, is used in the opposite application for which it was designed. Upper driveshaft bearing and bearing housing. The housing is removed first, and then the bearing, but only if the bearing is unfit for further service. Pinion Gear Bearing Removal 18-If the bearing has been damaged to the point where it must be replaced, it may be driven out with a punch, or other suitable tool, because further damage is no loss. Drive the bearing downward into the bore of the lower unit. Forward Gear Bearing Removal This bearing should only be removed if the bearing or gear is damaged and is to be replaced. 19-A beveled clamp-type arrangement, as shown in the accompanying illustration, is required. Such a tool will exert a force between the bearing and the gear in order to remove the bearing without harm. Install the clamp and tighten it around the bearing. Now, push in the center of the bearing. The gear and bearing will separate. SHIFT NO DISCONNECT 8-23 Seal Removal from the Gearcase Head 20-Remove the 0-ring and then reinstall the head back onto the lower unit. Tighten the two retaining bolts. Use a slide hammer to remove the two seals from the gearcase head. Remove the two retaining bol ts and again remove the head of the lower unit. Seal Removal from the Gearcase Cover 21-Use special tool OMC No. 31 9880 or any type of punch to remove the seals. lfthe seal has been damaged to the poin t where it must be replaced, it may be driven ou t with a punch, or other suitable tool, because further damage is no loss. Shift Rod Seal Removal 22-Use the shift rod to remove the seal. Work the shift rod in the seal, and then push outward and the seal will pop out of the gear case cover. After the seal has been removed, remove the 0-r in g. CLEANING AND INSPECTING Clean all water pump parts with solvent, and then dry them with compressed air. Inspect the water pump cover and base for cracks and distortion, possibly caused from overheating. Inspect the face plate and water pump insert for grooves and/or rough surfaces. If possible, ALWAYS install a complete new water pump while the lower unit is disassembled. A new impeller will ensure extended satisfactory service and give "peace of mind" to the owner. If the old impeller must be returned to service, The side of the clutch dog shown must face toward the propeller. 8-24 LOWER UNIT NEVER install it in reverse to the original direction of rotation. Installation in reverse will cause premature impeller failure. Inspect the impeller side seal surfaces and the ends of the impeller blades for cracks, tears, and wear. Check for a glazed or melted appearance, caused from operating without sufficient water. If any question exists, and as previously stated, install a new impeller if at all possible. Clean all parts with solvent and dry them with compressed air. DISCARD all 0rings and gaskets. Inspect and replace the driveshaft if the splines are worn. Inspect the gearcase and exhaust housing for damage to the machined surfaces. Remove any nicks and refurbish the surfaces on a surface plate. Start with a No. 120 Emery paper and finish with No. 180. Check the water intake screen and passages by removing the bypass cover, if one is used. Inspect the clutch dog, drive gears, pinion gear, and thrust washers. Replace these items if they appear worn. If the clutch dog and drive gear arrangement surfaces are nicked, chipped, or the edges Shift ca m with the word UP embossed on the arm to ensure proper installation. rounded, the operator may be performing the shift operation improperly or the controls may not be adjusted correctly. These i terns MUST be replaced if they are damaged. Inspect the dog ears on the inside of the forward and reverse gears. The gears must be replaced if they are damaged. Check the clutch dog retaining spring to be sure it is not distorted. Pinion gear with the first thrust washer to be Removing the needle bearings from the upper driveinstalled. The inside diam eter of the washer is beveled. shaft bearing retainer. SHIFT NO DISCONNECT 8-25 *REVERSE GEAR THRUST WASHER 1984 AND ON EXTENS ION Exploded drawing of a lower unit for the 4.5 hp and 7.5 hp units, with major parts identified. 8-26 LOWER UNIT Two seals showing the back side (left) and the front side (right). When double seals are installed, they must always be installed back-to-back with Triple Guard Grease between the flat surfaces. LOWER UNIT ASSEMBLING READ AND BELIEVE The lower unit should not be assembled in a dry condition. Coat all internal parts with OMC HI-VIS lube oil as they are assembled. Gearcase Cover Seal Installation 1-Install one seal at a time --back-toback. Use OMC Adhesive Type-M and special tool OMC No. 326547 or a socket the same size as the seal. Press the first seal into place from the bottom side of the cover. 2-Coat the seal with Triple-Guard Grease. This type of grease will not dissipate, but remains to perform its lubricating job between the seals. 3-Press the second seal into the gear case cover from the bottom side using the special tool or the proper size socket. Shift Rod 0-ring and Bushing Installation 4-Slide the 0-ring into place in the gearcase cover head. Glue the shift rod bushing into the cover using OMC Adhesive Type-M. Pinion and Driveshaft Bearings --Installation If the pinion and driveshaft bearings were removed, they are installed simultaneously using special tools. There is no other way to install these bearings properly without the special OMC tools. Sorry about that! 5-Obtain special tool OMC No. 383173 and Spacer No. 383174. The pinion bearing is installed with the lettered side facing DOWN. The driveshaft bearing is installed with the lettered side facing UP. The tool will be pressing against the lettered side of each bearing. Work the bearings into place by tightening on the tool nut. Forward Gear Bearing Race Installation If the forward gear bearing race was removed, a new bearing can only be properly installed using a special OMC tool. As with the pinion and driveshaft bearings, there is no other way. Again, sorry about that! 6-Obtain special tool OMC No. 326025. Set the bearing race in the housing, and then use the tool and tap the race into position. Forward Gear Bearing Installation This bearing can be installed WITHOUT the use of a special tool. 7-Place the bearing in position on the forward gear with the taper facing AWAY from the gear. Press the bearing into position using a proper size socket. A short length of 1-1/4" O.D. pipe may also be used to install the bearing. SHIFT NO DISCONNECT 8-27 Gearcase Head Seal Installation These two seals are of different sizes -one small --the other larger. The smaller (narrow) seal is installed on the inside of the gearcase head with the lip facing INWARD. The larger (wide) seal is installed on the outside of the head with the lip facing OUTWARD. 8-Install each seal from the proper side of the gearcase head. Use Triple Guard Grease between the seals. This type of grease will not dissipate, but remain to perform its lubricating job. Install the 0-ring into the groove of the gearcase head. Set the gearcase cover assembly aside for installation later. 8-28 LOWER UNIT Shift Rod and Shift Cam Installation 9-Pickup the cam with a pair of needlenose pliers and observe the word UP embossed on the arm of the cam. Take special notice of the irregular shape of the cam arm. The long flat surface must butt up against the back side of the lower unit housing. Also observe the inside diameter of the cam with the flat area on the side next to the cam arm. 10-Using the needle-nose pliers, lower the shift cam down into the lower unit with the flat edge of the cam arm facing the PORT side and towards the BACK of the housing, as shown. Push the cam all the way in with the flat side of the cam against the back of the housing. In this position, when the shift rod is installed, the correct halfmoon area on the inside diameter of the cam will index in the cam and the shift rod will be the proper position. 11-Snap the E-clip into the recess of the shift rod, as shown. Insert the shift rod down through the lower unit housing and into the shift cam with the retaining ring going in FIRST. Check the shift rod to be SHIFT NO DISCONNECT 8-29 an aid to installing the gear case cover. Slide the gearcase cover down over the shift sure the flat area on the end of the rod is in the same plane (fore-and-aft) as shown in the accompanying illustration, "A", when viewed from the PORT side. SPECIAL NOTE When the shift rod is rotated to the position shown in illustration ''B", as viewed from the PORT side, the unit will be in NEUTRAL. When the shift rod is rotated further to the position shown in illustration "C", still viewed from the PORT side, the unit is in REVERSE. Gear Case Cover Installation 12-Place a NEW gasket on the bottom rod. Secure the gearcase cover to the lower unit with the retaining bolts. Tighten the bolts evenly and alternately to the torque value given in the Appendix. Pinion Gear Bearings Installation Onto Pinion Gear A bearing, two thrust washers, and a thrust bearing, are used on the pinion gear. The method and order of installation is most important. Notice how the inside diameter of one thrust washer is beveled. This washer is installed first with the beveled side facing DOWN. The thrust bearing is installed next, and finally the second thrust washer, with the outside beveled side facing UP. of the gear case cover. Coat the bottom side of the gearcase cover and the mating surface of the lower unit with OMC Adhesive Type-M. Coat the shift rod with oil as the pinion gear shank with the outside beveled side facing UP. the pinion gear shank with the outside beveled side facing UP. 8-30 LOWER UNIT 13-Coa t the thrust washers, the thrust bearing, and the shank of the pinion gear with OMC HI-VIS Gearcase Lubricant. Slide the thrust washer with the beveled side facing the pinion gear shank. 14-Slide the thrust bearing onto the shank with the flat side facing DOWN. 1.5-Slide the second thrust washer onto Lower Unit Assembling 16-Work the pinion gear assembly up into the lower unit housing through the pinion gear bearing previously installed into the housing. 17-Secure the lower unit in a horizontal position (90° from the normal position). Lower the forward gear into the lower unit housing with the gear tilted toward the cavitation plate and the gear teeth facing backward toward the opening. 18-Insert the propeller shaft through the opening and through the forward gear. SHIFT NO DISCONNECT 8-3 1 Forcefully pull the propeller shaft toward the skeg to snap the teeth of the forward into mesh with the teeth of the pinion gear. When the two gears have meshed, the propeller shaft will be in a vertical position. Withdraw the propeller shaft. Propeller Shaft Assembling 19-Observe the clutch dog. Notice the mark on the clutch dog indicating the propeller end. This end MUST be installed toward the propeller. 20-Coat the spring with lubricant, and then slide it into the center of the propeller shaft at the forward gear end. Lubricate, and then slide the clutch dog onto the propeller shaft with the mark on the clutch dog facing TOWARD the propeller end of the shaft. 21-Insert special tool OMC No. 390766 into the end of the propeller shaft , and depress the spring just installed. If the special tool is not available, a small screwdriver may be used. The job is not as easy gear. gear. 8-32 LOWER UNIT as with the tool, but with a little patience and time, the spring can be depressed and the pin inserted. With the spring depressed, insert the pin through the clutch dog and the propeller shaft. Center the pin through the clutch dog, and then remove the special tool. 22-Install the clutch dog spring retainer into the groove in the clutch dog. TAKE CARE not to stretch the spring as it is stretched over the clutch dog. If the spring is stretched, it will allow the pin to come free of the clutch dog. Propeller Shaft Assembly Installation 23-Apply some OMC HI-VIS lubricant to the plunger. Insert the square end of the plunger into the hole in the end of the propeller shaft. This plunger will make contact with the clutch dog pin through the propeller shaft. Lower the assembled propeller shaft into the lower unit, with care to prevent the plunger pin from being dislodged from the shaft. Work the end of the propeller shaft all the way into the forward 24-Models 1984 and later: Slide the thrust washer onto the propeller shaft. All Models: Slide the reverse gear on to the propeller shaft and seat it in the housing. 25-Coat the propeller shaft with lubricant. Place the 0-ring in position on the gearcase head. Slide the gearcase head down over the propeller shaft. Just before it reaches the lower unit surface, coat the 0-ring with gasket sealer compound, and then secure the head to the lower unit with the attaching bolts. 26-Tighten the bolts AL TERNA TEL Y and EVENLY to the torque value given in the Appendix. SHIFT NO DISCONNECT 8-33 WATER PUMP INSTALLATION 27-Secure the lower unit in the vertical (normal) position. Slide the driveshaft down through the lower unit until it indexes with the pinion gear. If necessary, rotate the shaft slightly to allow the splines on the shaft to index with the splines in the pinion gear. 28-Apply OMC Sealer to both surfaces of both water pump gaskets. Place one gasket in position on the surface of the gearcase cover. Place the water pump plate into position on the gasket with the rounded edge facing UPWARD. Place the second gasket in position on the top of the water pump plate. 29-Slide the impeller down the driveshaft. Before it reaches the keyway in the shaft, insert the key in the keyway, and then slide the impeller down onto the surface of the water pump plate. 30-Coat the inside surface of the water pump housing with light-weight oil, and then slide the housing down the dr iveshaft and over the impeller. Rotate the dr iveshaf t as the water pump housing is moved into place to allow the impeller blades to enter and lay back properly inside the housing. 31-Apply a coating of Loc tite to the water pump bolt threads. Secure the water pump to the lower unit with the bolts. Tighten the bolts EVENLY and ALTERNATELY to the torque value given in the 8-34 LOWER UNIT Appendix. Slide the 0-ring down the driveshaft and into place on top of the water pump. LOWER UNIT INSTALLATION SPECIAL INSTRUCTIONS Fill the lower unit with lubricant. Follow the procedures listed in Sec tion 8-3. Install the propeller, see Section 8-2. Check to be sure the spark plug wires are disconnected from the plugs. Verify the shift handle is in the FOR WARD gear posi tion. Check to be sure the lower unit shift is in the FORWARD gear position. This check can be accomplished by verifying the shift rod is turned tightly CLOCKWISE and that the unit is in forward gear. When the unit is in FORWARD gear, the flat portion of the shift rod will be in the same plane(fore-and-aft) as shown in the accompanying illustration, "A", when viewed from the PORT side. copy . Check to be sure the water pump tubes are clean, and then coat them with lubricant. Coat the 0-rings with oil. Coat the splines of the driveshaft with OMC Molylube. 32-Bring the lower unit together with the exhaust housing, and at the same time guide the water tubes and the driveshaft through the openings in the exhaust housing. Bring the assembled lower unit and the exhaust housing together with the powerhead, and at the same time guide the water tubes and the driveshaft into the place. Have an assistant slowly turn the propeller CLOCKWISE as the units are brought together to allow the splines on the end of the driveshaft to index with the splines in the crankshaft. Check to be sure the end of the shift rod indexes into the shift handle gear. 33-Install the retaining bolts securing the lower unit to the exhaust housing. Two bolts are installed up through the lower unit cavitation plate on each side of the zinc. A third bolt is installed down through the forward leading edge of the exhaust housing. Tigh ten the bolts ALTERNATELY and EVENLY to the torque value given in the Appendix. Install a new zinc and secure it in place wi th the Phillips screw. TROUBLESHOOTING MANUAL SHIFT 8-35 FUNCTIONAL CHECK Perform a functional check of the completed work by mounting the engine in a test tank, in a body of water, or with a flush attachment connected to the lower unit. If the flush attachment is used, NEVER operate the engine above an idle speed, because the no-load condition on the propeller would allow the engine to RUNAWAY resulting in serious damage or destruction of the engine. CAUTION: Water must circulate through the lower unit to the engine any time the engine is run to prevent damage to the water pump in the lower unit. Just five seconds without water will damage the water pump. Start the engine and observe the tattletale flow of water from idle relief in the exhaust housing. The water pump installation work is verified. If a "F lushe tte" is connected to the lower unit, VERY LITTLE water will be visible from the idle relief port. Shift the engine into the three gears and check for smoothness of operation and satisfactory performance. 8-6 TROUBLESHOOTING MANUAL SHIFT 6.0 HP TO 40 HP ALL MODELS EXCEPT 35 HP WITH PROPELLER EXHAUST SPECIAL WORDS The troubleshooting procedures in this section may be performed for any of the lower units covered in Sections 8-7 or 8-8. Troubleshooting MUST be done BEFORE the unit is removed from the powerhead to permit isolating the problem to one area. Always attempt to proceed with troubleshooting in an orderly manner. The shotgun approach will only result in wasted time, incorrect diagnosis, replacement of unnecessary parts, and frustration. The following procedures are presented in a logical sequence with the most prevalent, easiest, and less costly items to be checked listed first. Unable to Shift into Forward or Reverse Remove the propeller and check to determine if the shear pin has been broken, illustration A. If the unit being serviced has the shear pin at the rear of the propeller, the propeller should be removed and the 8-36 LOWER UNIT shear pin checked at the rear of the propeller shaft, illustration B. Check the Table of Contents for the horsepower and model yea.r of the unit being serviced. Each section clearly outlines exactly how the shift disconnect is to be made. If the section indicates the powerhead must be removecl in order to check the shift mechanism, then the pO\verhead must be removed. If the unit has a V'indow i.n the exhaust housing, then the window must be removed. Hold the shift rod with a pair of pliers and at the same time attempt to move the shift lever on the starboa.rd side of the engine. If it is possible to move the shi.ft lever, the bellcrank is worn, illustration C. If the engine is the type requiring the lower unit to be lowered slightly to gain access to the shift rod, proceed as follows: Lower the lower unit slightly, and then hold the shift rod with a pair of pliers and attempt to move the shift lever on the starboard side of the engine. If the lever can move, the bellcrank is worn and must be repaired. Water in the Lower Unit Water in the lower unit is usually caused by fish line becoming entangled around the propeller shaft behind the propeller and damaging the propeller seal, illustration D. If the line is not removed, it will cut the TROUBLESHOOTING MANUAL SHIFT 8-37 ® from the plugs, to prevent possible personal injury, should the engine start. Shift the propeller shaft seal and allow water to enter the lower unit. Fish line has also been known to cut a groove in the propeller shaft. The propeller should be removed each time the boat is hauled from the water at the end of an outing and any material entangled behind the propeller removed before it can cause expensive damage. The small amount of time and effort involved in pulling the propeller is repaid many times by reduced maintenance and service work, including the replacement of expensive parts, illustration E. Slippage in the Lower Unit If the shift seems to be slipping as the boat moves through the water: Check the propeller and the rubber hub, illustration F. If the propeller has been subjected to many strikes against underwa ter objects, it could unit into REVERSE gear at the shift control box, and at the same time have an assistant turn the propeller shaft to ensure the clutch is fully engaged. If the shift handle is hard to move, the trouble may be in the lower unit, with the shift cable, or in the shift box, if used. Isolate the Problem: Disconnect the shift cable, if used, at the engine, illustration G. Operate the shift lever. If shifting is still hard, the problem is in the shift cable or control box, illustration H, see Chapter 7. If the shifting feels normal with the shift cable disconnected, the problem must be in the lower unit. To verify the problem is in the lower unit, have an assistant turn the propeller and at the same time move the shift cable back-and-forth. Determine if the clutch engages properly. slip on its hub. If the hub is damaged or excessively worn on the small propellers, it is not economical to have the hub or propeller rebuilt. A new propeller may be purchased for considerably less than meeting the expense of rebuilding an old worn propeller. Difficult Shifting Verify tha t the ignition switch is OFF, or better still, disconnect the spark plug wires RUBBER HUB NEUTRAL FAST SLOW SH IFT 8-38 LOWER UNIT Jumping out of Gear If a loud thumping sound is heard at the transom while the boat is underway, the unit is jumping out of gear, the propeller does not have a load, therefore the rushing water under the hull forces the lower unit in a backward direction. The unit jumps back into gear; the propeller catches hold; the lower unit is forced forward again, and the result is the thumping sound as the action is repeated. Normally this type of action occurs perhaps once a day, then more frequently each time the clutch is operated, until finally the unit will not stay in gear for even a short time. The following areas must be checked to locate the cause: 1-Check the Table of Contents for the horsepower and model year of the unit being serviced. Each section dearly outlines exactly how the shift disconnect is to be made. If the section indicates the powerhead must be removed in order to check the shift mechanism, then the powerhead must be removed. If the unit has a window in the exhaust housing, then the window must be removed. Hold the shift rod with a pair of pliers and at the same time attempt to move the shift lever or:, the starboard side of the engine. If .it .is possible to move the shift lever, the bell crank is worn. If the engine is the type requiring the lower unit to be lowered slightly to gain access to the shift rod: Lower the lower unit slightly, and then hold the shift rod with a pair of pliers and attempt to move the shift lever on the starboard side of the engine. If the lever can move, the bellcrank is damaged and must be repaired. 2-Disconnect the shift cable at the engine. Attempt to shift the unit into forward gear with the shift lever on the starboard side of the engine and at the same time rotate the propeller in an effort to shift into gear. Shift the control lever at the control box into forward gear. Move the shift cable at the engine up to the shift handle and determine if the cable is properly aligned. The control lever may have jumped a tooth on the slider or on the shift lever arc. If a tooth has been jumped, the cable would lose its adjustment and the unit would fail to shift properly. If the inner cable should slip on the end cable guide, the adjustment would be lost. 3-Move the shift lever at the engine into the neutral position and the shift lever at the control box to the neutral position. Now, move the shift cable up to the shift lever and see if it is aligned. Shift the unit into reverse at the engine and shift the control lever at the control box into reverse. Move the cable up and see if it is aligned. If the cable is properly aligned, but the unit still jumps out of gear when the cable is connected, one of three conditions may exist. a-The bellcrank is worn excessively or damaged. b-The shift rod connec tor is misaligned. This connector is used to link the upper shift rod with the lower rod. If the connec tor has not been 'installed properly, any shifting will be difficult. c-Parts in the lower unit are worn from extended use. Frozen Powerhead This condition is suggested when the operator unsuccessfully attempts to crank the engine, either with a hand starter or with a starter motor. The flywheel will not rotate. Do not assume the engine is "frozen" until the lower unit has been removed and thoroughly checked. If the lower unit is "locked" (the driveshaft or propeller shaft will not rotate), the powerhead will have the indication of being "frozen" (failure to rotate the flywheel). The first step to perform under these conditions is to "pull" the lower unit, and then again attempt to crank the engine. If the attempt is successful with the lower unit disconnec ted, the problem is in the lower unit. If the attempt to crank the engine is still unsuccessful, the problem is in the powerhead, illustration J. MANUAL SHIFT 6.0 TO 25 HP 8-39 8-7 LOWER UNIT SERVICE MANUAL SHIFT 6.0 HP -1971-79 9.5 HP TO 20 HP -1971-73 25 HP -1971-85 Propeller Removal Remove the propeller according to the detailed procedures outlined in Section 8-2. Draining Lower Unit Drain the lower unit according to the detailed procedures outlined in Section 8-3. Shift Rod Disconnect Three different shift rod connection arrangements may be encountered on the engines covered in this manual. The following three paragrpahs describe the connections and how they are to be handled for removal of the lower unit. The horsepower and model years are also given for each. Pin in Upper Driveshaft Used on All 6 hp Engines -1971-79 "Pin in the upper driveshaft", means that the pin holds and pushes the seal and spring assembly against the powerhead and thus provides a bottom seal for the powerhead. After the lower unit attaching bolts have been removed, the flywheel must be rotated (to rotate the driveshaft) until the pin is aligned with two slots in the upper portion of the exhaust housing, illustration A. The lower housing can then be separated from 8-40 LOWER UNIT the exhaust housing. If an attempt is made to force the lower unit from the exhaust housing without aligning the driveshaft pin, as just described, the pin may be broken and other items damaged. Loosen the attaching screws securing ' the lower unit to the exhaust housing. Allow the lower unit to drop approximately one inch, and then remove the bottom bolt in the shift connec tor illustration B. The lower unit may then be completely separated from the exhaust housing, illustration C. Shift Disconnect Connector Used on All 9• .5 hp Engine -1971-73 These units do not have the pin in the driveshaft. Loosen the attaching screws securing the lower unit to the exhaust housing. Allow the lower unit to drop approximately one inch, and then remove the bottom bolt in the shift connector, illustation .B. The lower unit may then be completely separated from the exhaust housing, illus tration C. Window Removal To Gain Access 18 hp and 20 hp Engines -1971-73 2.5 hp Engines 1971-8.5 Remove the metal plate from the port side of the engine. Access to the shift connector is gained through the opening. Disconnect the shift rod from the ex haust housing by removing the bottom bolt from the shift connector, illustration D. GOOD WORDS In MOST cases, if any unit being serviced has the 6-inch extension, it is NOT necessary to remove the extension in order to "drop" the lower unit. However, as in most things in life, there are rare exceptions and here is one. If the lower unit is separated from the extension and the driveshaft connection is not accessible, then the extension will have to be removed to gain access to the coupler. LOWER UNIT REMOVAL 1-After the shift rod has been disconnected, as described in the previous paragraphs, remove the bolts securing the lower unit to the housing. Some units may have an additional bolt on each side and one at the rear of the engine. Work the lower unit loose from the exhaust housing. It is not uncommon for the water tube to be stuck in the water pump making separation of the lower unit from the exhaust housing difficult. However, with patience and persistence, the tube will come free of the pump and the lower unit separated from the exhaust housing. MORE GOOD WORDS Position the lower unit in a vertical position on the edge of the work bench resting on the cavitation plate. Secure the lower unit in this position with a C-clamp. The lower unit will then be held firmly in a favorable position for further service work. An alternate method is to cut a groove in a short piece of 2" x 6" wood to accommodate the lower unit with the cavitation plate resting on top of the wood. Clamp the wood in a vise and service work may then be performed with the lower unit erect (in its normal position), or inverted (upside down). In both positions, the cavitation plate is the supporting surface. 2-Remove the 0-ring from the top of the driveshaft. Some units may have a pin installed in this location, instead of an 0ring. In this case, remove the pin from the drives haft. The washer, springs, and other parts will have remained in the exhaust housing. WATER PUMP REMOVAL 3-Remove the screws securing the water pump to the lower unit housing. It is very possible corrosion will cause the screw heads to break-off when an attempt to remove them is made. If this should happen, MANUAL SHIFT 6.0 TO 25 HP 8-41 use a chisel and breakaway the water pump housing from the lower unit. ·EXERCISE CARE not to damage the lower unit housing. 4-After the screws have been removed, slide the water pump, impeller, the impeller key, and the lower water pump plate, upward and free of the driveshaft. 8-42 LOWER UNIT ADVICE If the only work to be performed is service of the water pump, be extremely CAREFUL to prevent the driveshaft from being pulled up and free of the pinion gear in the lower unit. NEVER carry the lower unit by the driveshaft. If the shaft should be released from the pinion, the lower unit MUST be disassembled to align the pinion gear and the driveshaft, then the driveshaft installed. To install the water pump, proceed directly to Page 8-52, Water Pump Installation. LOWER UNIT DISASSEMBLING GOOD WORDS One of two type of driveshafts may be installed in the lower units covered in this section. One has a spline on the lower end of the shaft to index with the splines in the pm10n gear. The other type driveshaft has a key and keyway in the lower end of the driveshaft. The key indexes with a matching keyway in the pinion gear. 5-CAREFULLY pull upward on the driveshaft. If the driveshaft comes free easily, the unit is the type with the splines on the end of the shaft. If the shaft will not come free, it is the type with the key and keyway. Therefore, the driveshaft will be removed later when the lower unit is disassembled. If the driveshaft comes free, remove it at this time. 6-Turn the lower unit upside down and again clamp it in the vise or slide it into the wooden block, if one is used. Carefully examine the lower portion of the unit. The cap is considered that part below the split with the skeg attached. The cap has a Phillips screw installed. Remove the screw. 7-Remove the attaching screws around the cap. These screws may be slotted-type or Phillips screws. CAREFULLY tap the cap to jar it loose, and then separate it from the lower unit housing. If the cap did not have a Phillips screw on the outside, observe the two slots inside the cap. TAKE TIME Before proceeding with the disassembly work, take time to study the arrangement of parts in the lower unit. You may elect to follow the practice of many professional mechanics and take a polaroid picture of the unit as an aid during the assembly work. Several engineering and production changes MANUAL SHIFT 6.0 TO 25 HP 8-43 have been made to the lower unit over the years. Therefore, the positioning of the gears, shims, bearings, and other parts may vary slightly from one unit to the next. To show each and every arrangement with a picture in this manual would not be practical. Even if it were done, the ability to associate the unit being serviced with the illustration would be almost impossible. Therefore, take time to make notes, scribble out a sketch, or take a couple photographs, illustration E. 8-Lift the shift lever out of the cradle, and then remove the cradle from the shift dog. Raise the propeller shaft and at the same time tap with a soft-headed mallet on the bottom side to jar it loose, then remove the shaft assembly from the lower unit. The forward and reverse gear including the bearings will all come out with the propeller shaft. The forward gear is the gear at the opposite end of the shaft :from the propeller. GOOD WORDS Notice the bearing split on the back side of the forward gear. Also observe the pin in the housing and a matching slot in the bearing. The pin must index in the slot during installation. The reverse gear has a tab protruding from the bearing head. This tab indexes in a slot in the housing during installation. By taking note at this time of the particular type of installation for the unit being serviced, the task of installation will progress more smoothly. If the installation work is not performed properly, the lower unit housing will quickly be damaged requiring the purchase of a new unit. 9-If the unit being serviced is the type with a keyway in the driveshaft, remove the pinion gear from the shaft, then the key, and snap ring, before attempting to remove the driveshaft. 10-Slide the forward gear, babbitt bearing, and washer, free of the propeller shaft. Remove the clutch dog. Remove the reverse gear case head, reverse gear, and washer, from the shaft. 11-Turn the lower unit housing right side up and again clamp it in the vise. Remove the bearing carrier and bearing assembly. This is accomplished by using a bearing carrier puller, as shown. An alternate method is to use two screwdrivers to remove the carrier from the lower unit. Sometimes the bearing carrier is difficult to remove. One effective method to release a stubborn bearing carrier is to heat the lower unit housing while attempting to remove the 8-44 LOWER UNIT Bearing carrier prior to removal. The two screws shown are used to align the carrier with the gasket during installation. carrier. If this method is employed, TAKE CARE not to overheat the lower unit. Excessive heat may damage internal parts. Remove the gasket from underneath the bearing carrier housing. 12-Clean the upper part of the shift rod as an aid to pulling it through the bushing and 0-ring. Pull the shift rod from the lower unit housing. The shif t rod passes through an 0-ring and bushing in the lower unit housing. These two items prevent water from entering the lower unit. A special tapered punch is required to remove the bushing from the lower unit housing. Obtain the special punch, and then remove the bushing, and the 0-ring. CLEANING AND INSPECTING Clean all water pump parts with solvent, and then dry them wi th compressed air. Inspect the water pump cover and base for cracks and distortion, possibly caused from overheating. Inspect the face plate and water pump insert for grooves and/ or rough surfaces. If possible, ALWAYS install a complete new water pump while the lower unit is disassembled. A new impeller will ensure extended satisfactory service and give "peace of mind" to the owner. If the old impeller must be returned to service, NEVER install it in reverse to the original direction of rotation. Installation in reverse will cause premature impeller failure. Inspect the impeller side seal surfaces and the ends of the impeller blades for cracks, tears, and wear. Check for a glazed or melted appearance, caused from operating without sufficient water. If any question exists, and as previously stated, install a new impeller if at all possible. Clean all parts with solvent and dry them with compressed air. DISCARD all 0rings and gaskets. Inspect and replace the driveshaft if the splines are worn. Inspect the gearcase and exhaust housing for damage to the machined surfaces. Remove any nicks and refurbish the surfaces on a surface plate. Start with a No. 120 Emery paper and finish with No. 180. Check the water intake screen and passages by removing the bypass cover, if one is used. Inspect the clutch dog, drive gears, pinion gear, and thrust washers. Replace these items if they appear worn. If the Using a slide hammer to "pull" the bearing carrier from the upper portion of the lower unit. clutch dog and drive gear arrangement sur faces are nicked, chipped, or the edges rounded, the operator may be performing the shift operation improperly or the con trols may not be adjusted correctly. These items MUST be replaced if they are dam::j: aged. Inspect the dog ears on the inside of the forward and reverse gears. The gears must be replaced if they are damaged. Worn clutch dog ears. This clutch dog must be replaced. Badly worn water pump impeller. The best practice is to replace the impeller each time the lower unit is disassembled for service. MANUAL SHIFT 6.0 TO 25 HP 8-45 A new shift cradle (right) compared with one badly worn and unfit for further service (left). Bearing head with a new seal and D-ring installed. Badly worn propeller shaft. This damage may have started from an entangled fish line that was not removed, and then aggravated when water entered the lower unit. Grommet installed about half-way up the exhaust A rusted and corroded gear. Water was allowed to housing where the water tube passes through. This enter the lower unit through a badly worn seal and grommet should be removed and the area cleaned to cause this damage to the gear and other expensive ensure satisfactory water flow through the unit. parts. 8-46 LOWER UNIT Badly worn pinion gear from a lower unit. The teeth of the gears must be carefully inspected for wear and damage. Check the cradle that rides on the inside diameter of the clutch dog. The sides of the cradle must be in good condition, free of any damage or signs of wear. If damage or wear has occurred, the cradle must be replaced. Check the shift lever and the two prongs that fit inside the cradle. Check to be sure the prongs are not worn or rounded. Damage or wear to the prongs indicates the lever must be replaced. READ AND BELIEVE The three accompanying lettered illustrations clearly show a lower unit that has been assembled INCORRECTLY .. Illustration F: Inspect very closely, the bushing bearing on the forward gear for any kind of indication the pin was missed when the housing was Installed during the last repair work. Check the reverse gearcase head and if there is any indication of a pin mark, then check the housing for evidence the pin has been driven into the housing. Some bearing carriers have a lip that indexes with a slot in the lower unit housing. Check for evidence the lip did not index properly. lllustration G: If the pin has been driven down into the lower unit housing, it must be drilled out as described in the next paragraph. The accompanying illustration compares a proper and an improper installation. Illustration H: If the pin must be drilled, EXERCISE CARE not too drill to deeply. If a hole is drilled deeper than necessary, then insert a couple drops of mel ted solder into the hole, and set the new pin in place with the LARGE portion of the pin flush with the housing. If the pin is not flush, remove it, drop more soldered into the hole and make another test. Continue to drop solder into the hole and test until the pin is flush with the housing when it is installed. If more solder is inserted into the hole than necessary, the pin may be tapped into the solder while it is still warm and the pin made flush with the housing. DRILL BIT ® MANUAL SHIFT 6.0 TO 25 HP 8-47 GROMMET SHIFT CONNECTOR PLATE HOUSING ,, SHIFT PROPELLER DRIVE..SH AFT SEAL , '! I' \ . BEARING / DOG SEAL I \\ PROPELLER SHAFT . I "-___// 0-RI NG SHIFT I PROPELLER FORWARD GEAR Exploded drawing of the lower unit for all the units covered in this section except the 6 hp units. 8-48 LOWER UNIT Exploded drawing of the lower W1it for the 6 hp W1it, with major parts identified. ASSEMBLING 1-Place the lower unit on the work bench with the water pump recess facing upward. Install a NEW 0-ring into the shift cavity. Work the bushing into place on top of the 0-ring with a punch and mallet. Inject just a couple drops of oil into the bushing and 0-ring as an assist during installation of the shift rod. 2-Turn the exhaust housing upside down. If the unit being serviced uses a Woodruff key, to secure the pinion gear to the driveshaft, install the driveshaft through the housing. Install the snap ring into the SHIFT ROD groove near the end of the driveshaft, and then the Woodruff key, and finally the pinion gear onto the driveshaft. Lower the assembled driveshaft into place in the lower unit housing. If the driveshaft is the splined- type, lower the pinion gear into place at this time. The driveshaft will be installed later. GASKET-® PLATE -@ S£AL "0" RIKG-o SE AL-@ SUPPORT PIN WASHER-@) DRIVE SHAFT RETAINER MANUAL SHIFT 6.0 TO 25 HP 8-49 0 Assembling the Propeller Shaft 3-Slide the clutch dog onto the propeller shaft splines. Apply a light coating of lubricant to the washer and then insert it into the center of the forward gear. Slide the forward gear onto the end of the propeller shaft. Slide the forward gear bearing onto the shaft and into the forward gear. 4-Apply a light coating of lubricant to the washer, and then insert it into the center of the reverse gear. Slide the reverse gear onto the propeller shaft from the propeller end. Check to be sure a new ring and bearing seal has been installed into the gear case head, and then install the gearcase head assembly onto the propeller shaft. CRITICAL WORDS Look into the front part of the lower unit housing. Notice the pin protruding up from the housing. Now, observe the slot in the forward gear bearing. When the propeller shaft assembly is installed into the lower unit, this pin MUST index into the hole in the forward gear bearing. Also notice the protrusion on the end of the gearcase head, illustration A. This protrusion MUST index with the slot in the housing when the propeller shaft assembly is installed. 5-Check to be sure the pinion gear is properly located. Check to be sure the shift rod is clean and smooth (free of any burrs or corrosion). Coat the shift rod and the 0ring with oil as an aid to installation. Slide the shift rod down through the 0-ring and bushing into the gear case. 6-Slide the propeller shaft assembly into the lower unit housing. Check to be sure the slot in the forward gear bearing indexes with the pin in the lower unit, and the protrusion on the end of the gear case head indexes in the slot in the housing. On some models, a pin in the lower unit housing MUST index with a hole in the gearcase head. 7-Lubricate the cradle, and then slip it into the clutch dog groove. 8-Bring the shift lever down over the cradle and snap the fingers of the lever into the cradle. Check to be sure the clutch dog 8-50 LOWER UNIT is in the NEUTRAL position. Push or pull on the shift rod to move it up or down until the clutch dog is in the center between the forward and reverse gears. 9-Lay down a bead of No. 1000 Sealer into the groove of the cap in preparation to installing the seal. 10-Place a NEW seal in the lower cap and hold the seal in the groove with sealer. Apply a small amount of silicone sealer on each side of the bearing gear case head. This sealer will form a complete seal when the lower unit cap is installed. GOOD WORD If time is taken to grind the end of the screw to a SHORT point, it will make the task of installation much easier, illustration B. If the cap and shift lever are not aligned exactly, the screw will "seek" and make the alignment as it passes through. However, do not make a long point or the screw will not have enough support and would bend during operation of the shift lever. 11-Position the lower unit cap over the gear assembly onto the lower unit housing. If the unit being serviced uses a shift lever pin, work the cap until the pin indexes into the recess of the cap. MANUAL SHIFT 6.0 TO 25 HP 8-51 12-Apply a drop of sealer into the opening for each cap retaining screw to ensure a complete seal between the cap and the lower unit housing. Install the screws securing the cap to the lower unit housing. Tighten the screws ALTERNATELY and EVENLY. 13-A Phillips screw is used in the side of the cap. Use a flashlight and align the hole in the cap with the hole in the shift lever. Install the tapered Phillips screw into the housing and through the lever. 14-Apply a drop of good grade sealer to the threads, and then tighten the screw securely. 15-Turn the lower unit rightside up. Install a NEW gasket onto the upper surface of the lower unit. 16-Install the bearing housing and bearing assembly by sliding a couple of bolts through the housing to align the base gasket. 8-52 LOWER UNIT WATER PUMP INSTALLATION 17-Apply a coating of sealer to the upper surface of the lower unit. Install the water pump base plate. 18-If the unit being serviced, uses the splined-type driveshaft, slide the driveshaft into the lower unit, and then rotate the shaft very slowly. When the splines of the dr iveshaft index with the pinion gear, the shaft will drop slightly. Install the water pump pin or key. 19-Slide the water pump impeller down the driveshaft and into place on top of the water pump base plate with the pump pin or key indexed in the impeller. Lubricate the inside surface of the water pump with lightweight oil. 20-Lower the water pump housing down the driveshaft and over the impeller. Rotate the driveshaft CLOCKWISE as the water pump housing is lowered to allow the impeller blades to assume their natural and proper position inside the housing. Continue to rotate the driveshaft and work the water pump housing downward until it is seated on the lower unit upper housing • 21-Rotate the driveshaft CLOCKWISE while the screws are tightened to prevent damaging the impeller vanes. If the impeller is not rotated, the housing could damage or cut the end of the vanes as the screws are brought up tight. The rotation allows them to spring back in a natural position. Place a NEW grommet into the water pump housing for the water pickup. If a new water pump was installed, this seal will already be in place. MANUAL SHIFT 6.0 TO 25 HP 8-53 ® 22-Install a NEW 0-ring on the top of the driveshaft. 23-If the lower unit being serviced uses a pin on the top of the driveshaft, install the pin at this time. Shift the lower unit into FOR WARD gear and at the same time rotate the propeller shaft CLOCKWISE. The lower unit assembling is now complete and ready to mate with the exhaust housing. LOWER UNIT INSTALLATION GOOD WORDS If the unit being serviced uses the shift rod connector arrangement either through the window or before the lower unit and exhaust housings are fully mated, these words are extremely critical. Connecting the shift rod with the connector is not an easy task but can be accomplished as follows: First, notice the cutout area on the end of the shift rod. This area permits the bolt to pass through the connector past the shift rod, and into the other side of the connector. It is this bolt that holds the shift rod in the connector. Now, in order for the bolt to be properly installed, the cutout area on the shift rod MUST be aligned in such a manner to allow the bolt to be properly installed. Therefore, as the lower unit is mated with the exhaust housing, exercise patience as the two units come together, to enable the bolt to be installed at the proper time. If the rod is allowed to move too far in to the connec tor before the bolt is Installed, it may be possible to force the bolt into place, past the shift rod. The threads on the bolt will be stripped, and the shif t rod will eventually come out of the connector, illustra tion C and D. 24-Install the connector on to the lower unit shift rod, with the NO THREAD section facing towards the window. With the connector in this position, the bolt may be inserted through the connec tor and "catch" the threads on the far side. Install the connector bolt in the manner described in the previous paragraph. SPECIAL WORDS If the unit being serviced uses the shift rod connector arrangement, then the connector must be connected to the shift rod 8-54 LOWER UNIT BEFORE the lower unit is fully mated with the exhaust housing, as described in the previous step and the "Good Words", illustration C and D. If the unit being serviced uses the driveshaft with the pin, extreme care must be exercised as the shaft is guided into the exhaust housing to allow the pin to index with the groove in the housing, illustration If the unit being serviced uses the bolt through the window arrangement, insert the bolt into the connector. TAKE TIME to read and understand the "Good Words" just before Step 24, before making this connection. After the bolt is in place, install and secure the window with the attaching hardware, illustration F. 25-Check to be sure the water pickup tube is clean, smooth, and free of any corrosion. Coat the water pickup tube and grommet with lubricant as an aid to installation. Guide the lower unit up in to the Shift rod connector on a lower unit requiring the powerhead to be removed to gain access to the connector. exhaust housing with the water tube sliding into the rubber grommet of the water pump. If the shift rod must be connected before the lower unit makes contact with the exhaust housing, make the connection at this time. Continue to work the lower unit towards the exhaust housing, and at the same time rotate the propeller shaft as an aid to indexing the driveshaft splines with the crankshaft. Start the bolts securing the lower unit to the exhaust housings together. Tighten the bolts ALTERNATELY and EVENLY to the torque value given in the Appendix. SPECIAL PROCEDURES Fill the lower unit with lubricant according to the procedures in Section 8-3. Install the propeller, see Section 8-2. 26-Final adjustment for r-emote control units: Shift the lower unit into NEUTRAL gear. At the shift box, move the shift lever to the NEUTRAL position. If the pin on the end of the shift cable, does not align with the shift handle, move the adjusting knob until the pin aligns and will move into the shift handle. With the shift cable removed, move the lower unit into FORWARD gear and at the same time rotate the propeller CLOCKWISE to ensure the gears are fully indexed. At the control box, move the shift MANUAL SHIFT 6.0 TO 25 HP 8-55 lever into the FORWARD position. Again check to be sure the pin on the end of the shift cable aligns with the hole in the shift lever. Adjust the knob on the shift cable until the pin does align with the hole in the shift lever. FUNCTIONAL CHECK Perform a functional check of the completed work by mounting the engine in a test tank, in a body of water, or with a flush attachment connected to the lower unit. If the flush attachment is used, NEVER operate the engine above an idle speed, because the no-load condition on the propeller would allow the engine to RUNAWAY resulting in serious damage or destruction of the engine. CAUTION: Water must circulate through the lower unit to the engine any time the engine is run to prevent damage to the water pump in the lower unit. Just five seconds without water will damage the water pump. Start the engine and observe the tattletale flow of water from idle relief in the exhaust housing. The water pump installation work is verified. If a "F lushe tte" is connected to the lower unit, VERY LITTLE water will be visible from the idle relief port. Shift the engine into the three gears and check for smoothness of operation and satisfactory performance. Small horsepower unit mounted in a test tank in preparation to making final adjustm ents and return to service. 8-56 LOWER UNIT 8-8 LOWER UNIT SERVICE MANUAL SHIFT -EARLY 40 HP TO 1976 (40 HP SINCE 1977 -SEE SEC. 8-1 3) Propeller Removal Remove the propeller according to the detailed procedures outlined in Section 8-2. Draining Lower Unit Drain the lower unit according to the detailed procedures outlined in Section 8-3. GOOD WORDS Only one type of shift mechanism and removal procedures are used on the engines covered in this section. Access to the shift disconnect is through a window on the starboard side of the engine. LOWER UNIT REMOVAL 1-Remove the metal plate from the port side of the engine. Access to the shift connec tor is gained through the opening. Disconnect the shift rod from the exhaust housing by removing the bottom bolt from the shift connector. GOOD WORDS In MOST cases, if any unit being serviced has the 6-inch extension, it is NOT necessary to remove the extension in order to "drop" the lower unit. 2-Remove the attaching hardware se the bolts securing the lower unit to the exhaust housing. Remove the bolts securing the lower unit to the housing. Some units may have an additional bolt on each side and one at the rear of the engine. Work the lower unit loose from the exhaust housing. It is not uncommon for the water tube/s to be stuck in the water pump making separation of the lower unit from the exhaust housing difficult. However, with patience and persistence, the tube/s will come free of the pump and the lower unit separated from the exhaust housing. curing the rear exhaust housing cover, installed on all 40 hp models. This cover MUST be removed to gain access to one of EARLY MANUAL SHIFT 401-P 8-57 MORE GOOD WORDS ·,, ' ..WATER PUMPHOUS lNG Position the lower unit in a vertical position on the edge of the work bench resting on the cavitation plate. Secure the lower unit in this position with a C-clamp. The lower unit will then be held firmly in a favorable position for further service work. An alternate method is to cut a groove in a short piece of 2" x 6" wood to accommodate the lower unit with the cavitation plate resting on top of the wood. Clamp the wood in a vise and service work may then be performed with the lower unit erect (in its normal position), or inverted (upside down). In both positions, the cavitation plate is the supporting surface, illustration A. 3-Remove and DISCARD the 0-ring from the top of the driveshaft. WATER PUMP REMOVAL AUTHOR'S APOLOGY The photographs taken for this section involved a water pump from an electric shift lower unit. However, the pump and the service procedures are identical for the manual shift. Therefore, disregard any wiring shown in the photographs. 4-Remove the 0-ring from the top of the water pump. Remove the screws securing the water pump to the lower unit housing. It is very possible corrosion will cause the screw heads to break-off when an attempt to remove them is made. If this should happen, use a chisel and breakaway the water pump housing from the lower unit. EXERCISE CARE not to damage the lower unit housing. 5-After the screws have been removed, slide the water pump, impeller, the impeller key, and the lower water pump plate upward and free of the driveshaft. GOOD NEWS If the only work to be performed is service of the water pump, disregard the following steps, and proceed directly to the Water Pump Assembling portion of this section on Page 8-67, Water Pump Installation. LOWER UNIT DISASSEMBLING 6-CAREFULLY pull upward on the driveshaft and remove it from the lower unit. 7-Turn the lower unit upside down and again clamp it in the vise or slide it into the wooden block, if one is used. Carefully examine the lower portion of the unit. The cap is considered that part below the split with the skeg attached. Remove the Phillips screw from the starboard side of the 8-58 LOWER UNIT PHILLIPS SCREW To show each and every arrangement with a picture in this manual would not be practical. Even if it were done, the ability lower housing. This screw passes through the shift yoke and threads into the other side of the housing. 8-Remove the attaching screws around the cap. These screws may be slotted-type or Phillips screws. CAREFULLY tap the cap to jar it loose, and then separate it from the lower unit housing. TAKE TIME Before proceeding with the disassembly work, take time to study the arrangement of parts in the lower unit. You may elect to follow the practice of many professional mechanics and take a polaroid picture of the unit as an aid during the assembly work. Several engineering and production changes have been made to the lower unit over the years. Therefore, the positioning of the to associate the unit being serviced with the illustration would be almost impossible. Therefore, take time to make notes, scribble out a sketch, or take a couple photographs, illustration B. 9-Lift the shift lever out of the cradle ' and then remove the cradle from the shift dog. Raise the propeller shaft and at the same time tap with a soft-headed mallet on the bottom side to jar it loose, then remove the shaft assembly from the lower unit. The forward and reverse gear including the bearings will all come out with the propeller shaft. The forward gear is the gear at the opposite end of the shaft from the propeller. GOOD WORDS Notice that the forward gear bearing is a tapered bearing with a race and that the taper faces outward, AWAY from the gear. Also observe the seal retainer on the propel gears, shims, bearings, and other parts may vary slightly from one unit to the next. ler end of the propeller shaft. Now, notice the matching pin in the lower unit housing. During the installation work, the retainer EARLY MANUAL SHIFT 40HP 8-59 MUST be installed with the pin indexed in the hole. Take note of the snap ring installed between the thrust washer and the reverse gear bearing. One more item of particular interest. Notice the two sides of the thrust washer. One side is as a normal washer, but the other side is a babbitt. The babbitt side MUST face toward the reverse gear during installation. The washer also has two dog ears, one facing upward and the other downward, illustration C. By taking note at this time of these items and exactly how they are installed, the task of assembling and installation will progress more smoothly. 10-Remove the attaching screws, and then the U-shaped bracket from the top of the pinion gear 11-Reach into the lower housing and remove the pinion gear. 12-Slide the tapered bearing, forward gear, washer, and clutch dog, off the propeller shaft. 13-Remove the seal retainer, reverse bearing, snap ring, washer, reverse gear and bearing, and the washer, from the propeller end of the shaft. 14-Turn the lower unit housing right side up and again clamp it in the vise. Remove the upper seal using a seal puller. An alternate method, if the puller is not available, is to use two screwdrivers and 8-60 LOWER UNIT Using a slide hammer to remove the seals or bearing from W1derneath the water pump base plate. work the seal out of the housing. TAKE CARE not to damage the seal recess as the seal is being removed. A babbitt bearing is installed under the seal. Late model units may have caged needle bearings installed. Normally, it is NOT necessary to remove this bearing. However, check the bearing surface with a finger and if any roughness is felt, the bearing MUST be replaced. 15-Clean the upper portion of the shift rod as an aid to pulling it through the bushing and 0-ring. Pull the shift rod from the lower unit housing. 16-The shift rod passes through an 0ring and bushing in the lower unit housing. These two items prevent water from entering the lower unit. A special tapered punch is required to remove the bushing from the lower unit housing. Obtain the special punch, and then remove the bushing, and the 0-ring. CLEANING AND INSPECTING Clean all water pump parts with solvent, and then dry them with compressed air. Inspect the water pump cover and base for cracks and distortion, possibly caused from overheating. Inspect the face plate and water pump insert for grooves and/or rough surfaces. If possible, ALWAYS install a complete new water pump while the lower unit is disassembled. A new impeller will ensure extended satisfactory service and give "peace of mind" to the owner. If the old impeller must be returned to service, NEVER install it in reverse to the original direction of rotation. Installation in reverse will cause premature impeller failure. Caged needle bearing set installed on newer model lower W1its instead of a babbitt bearing. EARLY MANUAL SHIFT 401-P 8-6 1 Babbitt bearing unfit for further service. This type bearing must not show any sign of water damage. Inspect the impeller side seal surfaces and the ends of the impeller blades for cracks, tears, and wear. Check for a glazed or melted appearance, caused from operating without sufficient water. If any question exists, and as previously stated, install a new impeller if at all possible. Clean all parts with solvent and dry them with compressed air. DISCARD all 0rings and gaskets. Inspect and replace the driveshaft if the splines are worn. Inspect View of a badly corroded lower unit. Water entered and was allowed to remain over an extended period of time causing extensive damage. Badly worn pinion gear from a lower unit. The teeth of the gears must be carefully inspected for wear and damage. A rusted and corroded gear. Water was allowed to Caged ball bearing set destroyed due to lack of enter the lower unit through a badly worn seal and lubrication, vibration, corrosion, metal particles, or all cause this damage to the gear and other expensive the above. parts. 8-62 LOWER UNIT A new shift cradle (right) compared with one badly worn and unfit for further service (left). the gearcase and exhaust housing for damage to the machined surfaces. Remove any nicks and refurbish the surfaces on a surface plate. Start with a No. 120 Emery paper and finish with No. 180. Check the water intake screen and passages by removing the bypass cover, if one is used. Inspect the clutch dog, drive gears, pinion gear, and thrust washers. Replace these items if they appear worn. If the clutch dog and drive gear arrangement surfaces are nicked, chipped, or the edges rounded, the operator may be performing the shift operation improperly or the controls may not be adjusted correctly. These items MUST be replaced if they are damaged. Inspect the dog ears on the inside of the forward and reverse gears. The gears must be replaced if they are damaged. Check the cradle that rides on the inside diameter of the clutch dog. The sides of the The web area indicated should be inspected carefully for the slightest sign of a hairline crack. The smallest evidence of a crack is cause to replace the housing because exhaust gases will find their way into the water p1mp area when the engine is operated and and the boat planing. These exhaust gases will cause the engine to run hot. Distorted tapered bearing unfit for further service. cradle must be in good condition, free of any damage or signs of wear. If damage or wear has occurred, the cradle must be replaced. Check the shift lever and the two prongs that fit inside the cradle. Check to be sure the prongs are not worn or rounded. Damage or wear to the prongs indicates the lever must be replaced. Using a punch to remove the seal from the bearing retainer. Installing a seal into the bearing retainer. Notice the D-ring has been installed. EARLY MANUAL SHIFT 40HP 8-63 TUBE GROMMET BUSH ING (SEE NOTE 2) 0 I HPELLER PUMP SCREEN HOUS ING PLATE 'G SHIFT HOUSING CONNECTOR ..l®iiJ SH IFT tJ .. RO.... BUSHING DRIVE\i.· SHAFT THRUST @. @"""' VAS HER BEARING--...._ "' li ' GEAR BEAR ING PROPELLER NUT I0-RING SEAL I 1 1 PIN ION BEAR ING A . SEAL RETAI NER ....= R.v:lSE PROPELLER CLUTCH FORWARD nDoGn SH IFT GEAR / YOKE FORWARD BEAR ING SEAL Exploded drawing of the lower Wlit for the 40 hp Wlits, with major parts identified. Notice the double water tubes out of the water pump and the detent spring and two detent balls in the propeller shaft. bushing into the gear case. Assembling the Propeller Shaft 5-Apply a light coating of lubricant to the washer, and then insert it into the center of the reverse gear. Slide the reverse gear onto the propeller shaft from the propeller end. Install the thrust washer with the babbitt side TOWARDS the reverse gear. Install the snap ring, the bearing. Check to bushing into the gear case. Assembling the Propeller Shaft 5-Apply a light coating of lubricant to the washer, and then insert it into the center of the reverse gear. Slide the reverse gear onto the propeller shaft from the propeller end. Install the thrust washer with the babbitt side TOWARDS the reverse gear. Install the snap ring, the bearing. Check to 8-64 LOWER UNIT be sure a NEW seal and 0-ring has been installed into the seal retainer, and then ASSEMBLING 1-Place the lower unit on the work bench with the water pump recess facing upward. Install a NEW 0-ring into the shift cavity. Work the bushing into place on top of the 0-ring with a punch and mallet. Inject just a couple drops of oil into the bushing and 0-ring as an assist during installation of the shift rod. 2-Lower the pinion gear into the housing. Check to be sure it seats properly. 3-Lower the U-shaped pinion gear retaining bracket into position and secure it in place with the attaching screws. 4-Check to be sure the pinion gear is properly located. Check to be sure the shift rod is clean and smooth (free of any burrs or corrosion). Coat the shift rod and the 0ring with oil as an aid to installation. Slide the shift rod down through the 0-ring and install the retainer. 6-Slide the clutch dog onto the propeller shaft splines. Apply a light coating of lubricant to the washer and then insert it into the center of the forward gear. Slide the forward gear onto the end of the propeller shaft. Slide the forward gear bearing onto the shaft with the large end of the taper TOWARDS the forward gear. Move the bearing into place on the forward gear. Forward bearing (right) with a non-replaceable bab- bitt bearing. Reverse bearing (left) with a sliding babbitt bearing that is replaceable. EARLY MANUAL SHIFT 401-P 8-65 Check to be sure a new 0-rihg and bearing seal has been installed into the gear case head, and then install the gearcase head assembly onto the propeller shaft. CRITICAL WORDS The seal retainer has a hole and the lower housing of the lower unit has a pin. This pin MUST index into the hole in the retainer when the propeller shaft is installed. If the pin is not seated properly in the hole, the seal retainer will work part way out of the housing and the lubricant in the lower unit will be lost, illustration A. 7-Slide the propeller shaft assembly into the lower unit housing. Check to be sure the forward and reverse gear index with the pinion gear and the hole in the seal retainer indexes with the pin in the lower unit housing. Lubricate the cradle, and then slip it into the clutch dog groove. 8-Bring the shift lever down over the cradle and snap the fingers of the lever into the cradle. Check to be sure the clutch dog is in the NEUTRAL position. Push or pull on the shift rod to move it up or down until the clutch dog is in the center between the forward and reverse gears. 9-Lay down a bead of No. 1000 Sealer into the groove of the cap in preparation to installing the seal. 10-Place a NEW seal in the lower cap and hold the seal in the groove with sealer. Apply a small amount of silicone sealer on each side of the bearing gear case head. This sealer will form a complete seal when 8-66 LOWER UNIT the lower unit cap is installed. Position the lower unit cap over the gear assembly onto the lower unit housing. 11-Apply a drop of sealer into the opening for each cap retaining screw to ensure a complete seal between the cap and the lower unit housing. Install the screws secur ing the cap to the lower unit housing. Tighten the screws ALTERNATELY and EVENLY. GOOD WORD If time is taken to grind the end of the screw to a SHORT point, it will make the task of installation much easier. If the cap and shift lever are not aligned exactly, the screw will "seek" and make the alignment as it passes through. However, do not make a long point or the screw will not have enough support and would bend during operation of the shift lever, illustration B. 12-Use a flashlight and align the hole in the cap with the hole in the shift lever. Install the tapered Phillips screw into the housing and through the lever. Tighten the screw securely. 13-Install the babbitt or needle bearing, if it was removed. The babbitt bearing may be installed using the proper size socket and hammer. If the caged needle bearing is installed tap on the numbered side of the bearing. 14-Coat the outside edge of a NEW seal with No. 1000 sealer, and then tap the seal into place in the top of the upper lower unit housing. EARLY MANUAL SHIFT 40HP 8-67 WATER PUMP INSTALLATION 15-Apply a coating of sealer to the upper surface of the lower unit. 16-Install the water pump base plate. Slide the driveshaft into the lower unit, and then rotate the shaft very slowly. When the splines of the driveshaft index with the pinion gear, the shaft will drop slightly. Install the water pump pin or key. 17-Slide the water pump impeller down the driveshaft and into place on top of the water pump base plate with the pump pin or key indexed in the impeller. Lubricate the inside surface of the water pump with lightweight oil. 18-Lower the water pump housing down the driveshaft and over the impeller. Rotate the driveshaft CLOCKWISE as the water pump housing is lowered to allow the impeller blades to assume their natural and proper position inside the housing. Continue to rotate the driveshaft and work the water pump housing downward until it is seated on the water pump plate. ALWAYS rotate the driveshaft CLOCKWISE while the screws are tightened to prevent damaging the impeller vanes. If the impeller is not rotated, the housing could damage or cut the end of the vanes as the screws are brought up tight. The rotation allows them to spring back in a natural position. Old type standard water pump (left) with new type (right). The new type must be used if the lower unit has been updated (replaced) with a new unit. Place NEW grommets into the water pump housing for the water pickup. If a new water pump was installed, this seal will already be in place. 19-Install a NEW 0-ring on the top of the driveshaft. 0-RING @ 8-68 LOWER UNIT LOWER UNIT INSTALLATION GOOD WORDS Connec ting the shift rod with the coupler is not an easy task but can be accomplished as follows: First, notice the cutout area on the end of the shift rod. This area permits the bolt to pass through the connector, past the shift rod, and into the other side of the connector. It is this bolt that holds the shift rod in the connector. Now, in order for the bolt to be properly installed, the cutout area on the shift rod MUST be aligned in such a manner to allow the bolt to be properly installed. Therefore, as the lower unit is mated with the exhaust housing, exercise patience as the two units come together, to enable the bolt to be installed at the proper time. If the rod is allowed to move too far into the connec tor before the bolt is installed, it may be possible to force the bol t into place, past the shift rod. The threads on the bolt will be stripped, and the shift rod will eventually come out of the connector, illustration C and D. 20-Install the connector, onto the lower unit shift rod, with the NO THREAD section facing towards the window. With the connector in this position, the bolt may be inserted through the connector and "catch" the threads on the far side. Install the connec tor bol t in the manner described in the previous paragraph. 21-Check to be sure the water pickup tubes are dean, smooth, and free of any corrosion. Coat the water pickup tubes and grommets with lubricant as an aid to installation. Guide the lower unit up into the exhaust housing with the water tube sliding into the rubber grommet of the water pump. Continue to work the lower unit towards the exhaust housing, and at the same time rotate the propeller shaft as an aid to indexing the driveshaft splines with the crankshaft. 22-Insert the bolt into the connector. TAKE TIME to read and understand the "Good Words" just before Step 20, before making this connection. After the bolt is in place, install and secure the window with the attaching hardware. Start the bolts securing the lower unit to the exhaust housing. Tighten the bolts EVENLY-and ALTERNATELY to the torque value given in the Appendix. 23-Install the rear cover over the exhaust housing. This cover is installed only on the 40 hp engines. When the cover is installed, check to be sure the icle relief rubber tube on the upper side underneath the powerhead fits into the recess of the cover. Secure the cover in place with the attaching hardware. Filling the Lower Unit Fill the lower unit with lubricant according to the procedures outlined in Seciton 8 3. Propeller Installation Install the propeller, see Section 8-2. Final Adjustment 24-Final adjustment for remote control units: Shift the lower unit into NEUTRAL gear. At the shift box, move the shift lever to the NEUTRAL position. If the pin on the EARLY MANUAL SHIFT 40t-P 8-69 @4 end of the shift cable, does not align with the shift handle, move the adjusting knob until the pin aligns and will move into the shift handle. With the shift cable removed, move the lower unit into FORWARD gear and at the same time rotate the propeller CLOCKWISE to ensure the gears are fully indexed. At the control box, move the shift lever into the FOR WARD position. Again check to be sure the pin on the end of the shift cable aligns with the hole in the shift lever. Adjust the knob on the shift cable until the pin does align with the hole in the shift lever. FUNCTIONAL CHECK Perform a functional check of the completed work by mounting the engine in a test tank, in a body of water, or with a flush attachment connected to the lower unit. If the flush attachment is used, NEVER operate the engine above an idle speed, because the no-load condition on the propeller would allow the engine to RUNAWAY resulting in serious damage or destruction of the engine. CAUTION: Water must circulate through the lower unit to the engine any time the engine is run to prevent damage to the water pump in the lower unit. Just five seconds without water will damage the water pump. Start the engine and observe the tattletale flow of water from idle relief in the exhaust housing. The water pump installation work is verified. If a "Flushette" is connected to the lower unit, VERY LITTLE water will be visible from the idle relief port. Shift the engine into the three gears and check for smoothness of operation and satisfactory performance. 8-70 LOWER UNIT 8-9 PROPELLER EXHAUST MECHANICAL SHIFT 9.9 HP -1974 AND ON 15 HP -1974 AND ON DESCRIPTION This lower unit has forward, neutral, and reverse shifting capabilities, with exhaust gases routed through the propeller. The lower unit must be separated slightly from the exhaust housing in order to disconnect the shift rod. GOOD WORDS Propellers with the exhaust passing through the hub MUST be removed more frequently than the standard propeller. Removal after each weekend use or outing is not considered excessive. These propellers do not have a shear pin. The shaft and propeller have splines which MUST be coated with an anti-corrosion lubricant prior to installation as an aid to removal the next time the propeller is pulled. Even with the lubricant applied to the shaft splines, the propeller may be difficult to remove. The propeller with the exhaust hub is more expensive than the standard propeller, therefore, the cost of rebuilding the unit, if the hub is damaged, is justified, illustration "A". A replaceable diffuser ring on the aft side of the propeller disperses the exhaust gases away from the propeller blades. If the ring becomes broken or damaged "ventillation" would be created pulling the exhaust gases back into the negative pressure area behind the propeller. This condition would create considerable air bubbles and reduce the effectiveness of the propeller. If the propeller is "frozen" onto the propeller shaft, see the special instructions for removal outlined in Section 8-14, Frozen Propeller Removal. TROUBLESHOOTING Troubleshooting MUST be done BEFORE the unit is removed from the powerhead to permit isolating the problem to one area. Always attempt to proceed with troubleshooting in an orderly manner. The shotgun approach will only result in wasted time, incorrect diagnosis, replacement of unnecessary parts, and frustration. The following procedures are presented in a logical sequence with the most prevalent, easiest, and less costly items to be checked, listed first. Water in the Lower Unit Water in the lower unit is usually caused by fish line becoming entangled around the propeller shaft behind the propeller and damaging the propeller seal. If the line is not removed, it will cut the propeller shaft seal and allow water to enter the lower unit. Fish line has also been known to cut a groove in the propeller shaft, illustration "8". The propeller should be removed each time the boat is hauled from the water at the end of an outing and any material entangled behind the propeller removed before it can cause extensive damage. The small amount of time and effort involved in pulling the propeller is repaid many times by reduced maintenance and service work, including the replacement of expensive parts, illustration "C". Slippage in the Lower Unitt: If the shift seems to be slipping as the boat moves through the water: Check the propeller and the rubber hub. If the propeller has been subjected to many strikes against underwater objects, it could slip on its hub. If the hub is damaged or excessively worn on the small propellers, it is not economical to have the hub or propeller rebuilt. A new propeller may be purchased for considerably less than meeting the expense of rebuilding an old worn propeller, illustration ''D". RUBBER HUB MECH SHIFT 9.9 AND 15 HP 8-7 1 Jumping Out of Gear If a loud thumping sound is heard at the transom while the boat is underway, the unit is jumping out of gear, resulting in a no-load condition on the propeller. When this happens, the rushing water under the hull forces the lower unit in a backward direction. The unit jumps back into gear; the propeller catches hold; the lower unit is forced forward again; and the result is the thumping sound as the action is repeated. Normally this type of action occurs perhaps once a day, then more frequently each time the clutch is operated, until finally the unit will not stay in gear for even a short time. The following areas must be checked to locate the cause: 1-Check the upper shift rod at the connection underneath the carburetor. 2-Attempt to correct the problem with better shift habits by the operator. 3-Check for water in the lower unit as described earlier in this section. 4-Normal wear at the upper and lower shift rod connection may cause the unit to jump out of gear. Frozen Powerhead This condition is suggested when the operator unsuccessfully attempts to crank the engine, either with a hand starter or with a starter motor. The flywheel will not rotate. Do not assume the engine is "frozen" until the lower unit has been removed Bellcrank located W1der the carburetor. The shift linkage is disconnected at this point, as described in the ® text. 8-72 LOWER UNIT and thoroughly checked. If the lower unit is "locked" (the driveshaft or propeller shaft will not rotate), the powerhead will have the indication of being "frozen" (failure to rotate the flywheel), illustration "E". The first step to perform under these conditions is to "pull" the lower unit, and then again attempt to crank the engine. If the attempt is successful with the lower unit disconnected, the problem is in the lower unit. If the attempt to crank the engine is still unsuccessful, the problem is in the powerhead. LOWER UNIT REMOVAL SPECIAL WORDS The lower unit must be separated slightly from the exhaust housing in order to disconnect the shift rod. The bearing carrier in the lower unit may be removed and the seals replaced without removing the lower unit. HOWEVER, this is not considered good practice because there is no way to check the bearings for damage if water has been allowed to enter the lower unit. Therefore, if the bearing carrier seals must be replaced, the lower unit should be removed and a complete inspection made of all other bearings and seals for water damage, illustration "F". Preliminary Tasks Drain the lower unit according to the procedures outlined in Section 8-3. Remove the propeller, see Section 8-2. If the propeller is "frozen" to the shaft, see special instructions outlined in Section 8-14. 1-Remove the engine hood. Disconnect the spark plug leads at the spark plugs. Remove the bolts securing the lower unit to the exhaust housing or to the 6-inch extension. In MOST cases, it is not necessary to remove the 6-inch extension in order to "drop" the lower unit. Separate the lower unit sJightly from the exhaust housing or the WATER PUMP HOUS ING unit sJightly from the exhaust housing or the WATER PUMP HOUS ING housing up and free of the driveshaft. 4-Remove the impeller and driveshaft key. Remove the water pump plate ancl gaskets from the lower unit. If the only work to be performed is service of the water pump, proceed directly to Page 8-86, Water Pump Installation. time to retrieve the two detent balls and the spring from inside the lower unit, illustration G. 5-Remove the two screws securing the bearing carrier in the lower unit. 6-inch extension. Reach in and remove the bottom bolt through the shift rod connector. The shift rod is now free to separate from the connector. CAREFULLY remove the lower unit straight away from the exhaust housing or the 6-inch extension. TAKE CARE not to pull backward, sideways, etc., when removing the lower unit, because the driveshaft may be bent. WATER PUMP REMOVAL 2-Remove the 0-ring from the top of the driveshaft. Remove the 0-ring and grommet from the top of the water pump. 3-Remove the bolts securing the water pump housing to the lower unit. Notice how the bolts from the aft holes are longer than the two bolts forward. Slide the impeller MECH SHIFT 9.9 AND 15 HP 8-73 Bearing Carrier Removal FIRST, THESE WORDS A hole is drilled through the propeller shaft just forward of the reverse gear. A detent spring is installed in the hole along with a detent ball on each side of the propeller shaft. The clutch dog is installed over the top of the two detent balls. This arrangement assists in holding the unit in the specific gear desired. When the bearing carrier, propeller shaft, and associated parts are removed, the clutch dog will remain in the lower unit. As soon as the clutch dog slides free of the propeller shaft, the detent balls and spring will fly free of the shaft, but be contained within the lower unit housing. Therefore, after the propeller shaft, bearing carrier, etc., are removed, take 8-74 LOWER UNIT GOOD WORDS Three methods are available to free the carrier from the lower unit. The first method involves the use of a special tool, OMC No. 386631. This tool is installed over the propeller shaft; the pro peller nut is threaded onto the shaft behind the tool; and then the tool extended with a wrench on both sides of the shaft; "pulling" the propeller shaft, bearing carrier, and reverse gear from the lower unit. On some bearing carriers, two threaded holes are provided in the carrier. The second method involves the use of a flywheel puller. Two long bol ts are installed into the threaded holes of the bearing carrier, while the center bolt is tightened against the end of the propeller shaft to pull the carrier free, illustration #H. The third method of removing the bearing carrier also utilizes the two threaded holes in the carrier. A slide hammer with a long rod is attached to the carrier and the carrier removed in that manner, illustration J. The propeller shaft and reverse gear are then removed, illustration K. 6-Reach in with a pair of needle-nose pliers and remove the clutch dog from the cradle, as shown. ® CLUTCH DOG MECH SHIFT 9.9 AND 15 f-P 8-75 7-Remove the driveshaft from the lower unit and at the same time, reach in and remove the pinion gear, two thrust washers, and the thrust bearing. Pay particular attention to the washers and how they are positioned on top of the pinion gear. One washer is noticeably thicker than the other. Also, one washer is beveled on the inside diameter and the other washer is beveled on the outside diameter. Take time to identify one of the washers with a dab of paint or other mark to ensure they will be installed in the same location from which they were removed. 8-Back out the shift rod from the yoke by turning it COUNTERCLOCKWISE until it is free. Withdraw the shift rod from the lower unit. 9-Remove the Phillips screw from outside of the lower unit. This is the screw very dose to the lubricant drain plug. The screw secures the shift lever and yoke assembly in position. After the screw is removed, the shift lever, yoke assembly, and forward gear may be removed from the lower unit. 10-Remove the forward gear tapered bearing from the lower unit. 11-Remove the forward gear bearing race. This race need NOT be removed unless the forward gear tapered bearing is to be replaced. The bearing and the race are sold as a matched pair. 8-76 LOWER UNIT Upper Driveshaft Seals -Removal 12-Use a slide hammer with finger-type pullers and remove the two seals. Notice how the two seals are installed back-toback. It is most important that they be installed in the same position from which they were removed. Upper Driveshaft Bearing Removal This bearing need NOT be removed, unless it is unfit for further service. Check the condition of the bearing by inserting a finger and rotating the bearing while checking for rough spots or evidence of binding. Use a flashlight and check to be sure there is no evidence of corrosion or other damage. 13-Use a slide hammer with fingers to remove the bearing, as shown in the accompanying illustration. ® Pinion Gear Bearing -Removal As with the upper driveshaft bearing, the lower bearing need NOT be removed unless it is unfit for further service. Check its condition in the same manner as described for the upper bearing. 14-Use a drift punch or other suitable tool and drive the bearing out of position into the lower unit. A special tool is not required because if the bearing is to be removed it is unfit for further service and additional damage will be of no consequence. Shift Rod 0-ring and Bushing Removal 15-Insert a length of 1/4" rod down through the 0-ring and bushing. Thread a nut onto the lower end of the rod. (The edges of the nut must be first rounded to permit the nut to pass through the opening in the housing). Attach a slide hammer to the rod and "pull" the 0-ring, bushing and washer. Bearing Carrier Seal Removal 16-Use a puller with two fingers and work the puller down into the seals. Take up on the puller and remove the seals. Notice how the seals are installed back-tohack. They must be installed in this manner to provide a proper seal to prevent the lubricant in the lower unit from escaping and water from entering. Bearing Carrier Bearing Removal The bearings in the bearing carrier need NOT be removed unless they are unfit for further service. Check their condition for damage and corrosion. Insert a finger inside and rotate the bearing while checking for roughness or any sign of binding. Use a flashlight and check for evidence of corrosion. ® MECH SHIFT 9.9 AND 15 HP 8-77 17-Use a punch and c'rive the bearing out. The bearing is being removed because it is unfit for service, therefore;& further damage is of no consequence. CLEANING AND INSPECTING Clean all water pump parts with solvent, and then dry them with compressed air. Inspect the water pump cover and base for Badly worn pinion gear from a lower unit. The teeth of the gears must be carefully inspected for wear and damage. 8-78 LOWER UNIT cracks and distortion, possibly caused from overheating. Inspect the face plate and water pump insert for grooves and/or rough surfaces. If possible, ALWAYS install a complete new water pump while the lower unit is disassembled. A new impeller will ensure extended satisfactory service and give "peace of mind" to the owner. If the old impeller must be returned to service, NEVER install it in reverse to the original direction of rotation. Installation in reverse will cause premature impeller failure. Inspect the impeller side seal surfaces and the ends of the impeller blades for cracks, tears, and wear. Check for a glazed or melted appearance, caused from operating without sufficient water. If any question exists, and as previously stated, install a new impeller if at all possible. Clean all parts with solvent and dry them with compressed air. DISCARD all 0rings and gaskets. Inspect and replace the driveshaft if the splines are worn. Inspect the gearcase and exhaust housing for damage to the machined surfaces. Remove any nicks and refurbish the surfaces on a surface plate. Start with a No. 120 Emery paper and finish with No. 180. Check the water intake screen and passages by removing the bypass cover, if one is used. Inspect the clutch dog, drive gears, pinion gear, and thrust washers. Replace these items if they appear worn. If the clutch dog and drive gear arrangement surfaces are nicked, chipped, or the edges The ears on this clutch dog and the teeth on the gear are badly worn. Both items are unfit for further service. rounded, the operator may be performing the shift operation improperly or the controls may not be adjusted correctly. These items MUST be replaced if they are damaged. Inspect the dog ears on the inside of the forward and reverse gears. The gears must be replaced if they are damaged. Check the cradle that rides on the inside diameter of the clutch dog. The sides of the cradle must be in good condition, free of any damage or signs of wear. If damage or wear has occurred, the cradle must be replaced. Check the shift lever and the two prongs that fit inside the cradle. Check to be sure the prongs are not worn or rounded. Damage or wear to the prongs indicates the lever must be replaced. A rusted and corroded gear. Water was allowed to enter the lower unit through a badly worn seal and cause this damage to the gear and other expensive New clutch dog and gear. Compare these two parts parts. with those shown at the top of this column. MECH SHIFT 9.9 AND IS HP 8-79 NUT\ COTTER ,..-/PIN THRUST WASHER PROPELLER SHIFTER LEVER AND YOKE ASSEMBLY Exploded drawing of the lower W1it for the 9.9 hp and 15 hp W1its with major parts identified. Notice the detent spring and two detent balls in the propeller shaft. CD sembled bearing carrier aside for later installation. CD sembled bearing carrier aside for later installation. 8-80 LOWER UNIT LOWER UNIT ASSEMBLING READ AND BELIEVE The lower unit should not be assembled in a dry condition. Coat all internal parts with OMC HI-VIS lube oil as they are assembled. All seals should be coated with OMC Gasket Seal Compound. When two seals are installed back-to-back, use Triple Guard Grease between the seal surfaces. Forward and Rear Bearing Installation Into the Bearing Carrier 1-If these two bearings were removed during disassembling because they were unfit for service, special tools are required to install the new bearings. Special tool OMC No. 31 9876 is required to install the rear bearing into the bearing carrier. Obtain the tool and press on the lettered side of the bearing until the bearing is fully seated in the bearing carrier. Special tool OMC No. 31987 5 is required to install the front bearing into the bearing carrier. Obtain the special tool and press against the lettered side of the bearing until the bearing is in place in the bearing carrier. A set of double seals showing the back side (left) and the front side (right). These seals are installed back-to-back (flat side-to-flat side) with Triple Guard Grease between the surfaces. This arrangement prevents fluid from passing in either direction. Bearing Carrier Seals -Installation . These seals are installed one at-a-time, back-to-back. 2-Special tool OMC No. 31 9877, or a socket the same size as the seal may be used to install the seals. Coat the outside surface of the seal with OMC Lubricant and press the first seal into place in the bearing carrier bore, with the back side of the seal facing OUTWARD. After the seal is in place, apply a coating of Triple Guard Grease to the seal surface. Install the second seal into the bearing carrier, with the back side of the seal facing INWARD. Install a NEW 0-ring onto the outside surface of the bearing carrier. Set the as CD MECH SHIFT 9.9 AND 15 HP 8-81 Pinion Gear Bearings -Installation SPECIAL WORDS The lower pinion gear bearing MUST be installed from the bottom cavity of the lower unit. The upper pinion gear bearing is pressed into place from the top. 3-If the lower pinion gear bearing was removed during disassembling because it was unfit for further service, obtain special tools OMC No. 31 9878 and No. 3831 73. Using these special tools is the only way the bearing may be installed properly. Actually, the bearing is "pulled" up into place with the special tools. Place the bearing in position for installation with the lettered side facing DOWN. Insert the special tool through the opening in the lower unit and through the bearing. Thread the bolt into the special tool and "pull" the bearing up into place in the lower unit. 4-To install the upper pinion gear bearing, obtain special tool OMC No. 319931 or No. 326566. Place the bearing in position with the lettered side facing UP. Use the special tool and press the bearing into place. 5-Install the upper driveshaft seals back-to-back. Coat the surfaces between the two seals \dth Triple Guard Grease. Shift Rod 0-ring and Bushing -Installation 6-Lower the washer, 0-ring, and bushing for the shift rod into place in the lower unit housing. Obtain special tool OMC No. 304515. Tap the bushing into place with a hammer and the special tool until the bushing is fully seated in the housing. If the special tool is not available, a socket or other similar tool may be used to install the bushing PROVIDED the tool will not damage the bushing during the installation process. 8-82 LOWER UNIT Forward Gear Bearing Race -Installation 7-Obtain special tool OMC No. 319929 and drive handle OMC No. 311880. Seat the tool into the bearing race. Drive the race into place in the lower unit. If the leading edge of the lower unit is placed on a block of wood, or other solid non-mar surface, when the race is driven into place, each blow will be firm without "bounce" and the lower unit housing will not be damaged or scarred. 8-Insert the forward gear bearing into the race installed in the previous step. WORDS OF ADVICE The following operation, installation of the forward gear shift lever and cradle, requires time and patience. Make an effort to keep a cool tool without becoming frustrated, and the installation will be accomplished in a reasonable time. A special flexible tool is listed, OMC No. 319991, to install these parts. The cable is threaded into the yoke and fed up through the lower unit. When the assembled propeller shaft is inserted into the lower unit, the cable is pulled through the lower unit and thus the short extension of the yoke will be guided into the shift rod hole. However, if the tool is not available, time and patience will result in victory, and the unit will function properly. Without the special tool, proceed as outlined in the next step. ADVICE Perform Steps 9 and 10 together. 9-Slide the forward gear into the shift lever and yoke assembly. Slip the cradle into the fingers of the shift lever. Coat the shift rod with oil. Insert the assembly into the lower unit and work the top part of the yoke up into the recess where the shift rod comes through. 10-At the same time, insert the shift rod down through the lower unit and shift rod bushing. Thread the shift rod into the shift lever yoke assembly four or five complete turns. An adjustment for the shift rod will be made later in Step 21. MECH SHIFT 9.9 AND 15 HP 8-83 Pinion Gear Installation 11-Observe the two p1mon gear washers. One washer is beveled on an inner edge and the other washer is beveled on an outer egde. Slide the washer with the inner edge bevel onto the shank of the pinion gear with the bevel facing DOWN. 12-Slide the thrust bearing onto the shank of the pinion gear. 13-Slide the remaining beveled washer onto the shank with the bevel on the outer egde facing UP. 14-Slide the pmwn gear shank up into the pinion gear bearing, and at the same time, lower the driveshaft down through the lower unit and into the pinion gear. Rotate the driveshaft very slightly after it makes contact with the pinion gear to allow the splines on the shaft to index with the splines of the gear. Clutch Dog InstallatioJJD 15-Pick up the clutch dog and notice the grooves on one side of the outside surface. When the clutch dog is installed, way grease is not used, they will not remain in place while the propeller shaft is installed into the lower unit. Slide the spring into the shaft and place the two balls in position. Place the lower unit in a horizontal position with the opening facing up. Insert the propeller shaft into the lower unit with the shaft in the position that places the balls on each side, as shown. In this position the balls should be aligned way grease is not used, they will not remain in place while the propeller shaft is installed into the lower unit. Slide the spring into the shaft and place the two balls in position. Place the lower unit in a horizontal position with the opening facing up. Insert the propeller shaft into the lower unit with the shaft in the position that places the balls on each side, as shown. In this position the balls should be aligned 8-84 LOWER UNIT these grooves MUST face the forward gear, illustration A. Grasp the clutch dog with a pair of needle-nose pliers and insert it into the cradle of the yoke assembly with the grooved side going in FIRST. Life is not a bowl of cherries, and this is not the easiest task, but if the cradle is tilted back slightly it will help with the installation. Work slowly and with patience, and the clutch dog will be properly seated in the yoke assembly. Propeller Shaft Installation 16-Coat the propeller shaft, the detent spring, and two detent balls, with needle bearing grease or similar lubricant to hold them in place during installation of the shaft. The detent balls do not seat all the into the shaft holes. Therefore, if with the ramps in the clutch dog. The detent balls must ride in a groove inside the clutch dog. Continue moving the propeller shaft into the lower unit housing until the shaft indexes into the clutch dog. Align the detent balls with the ramps on the clutch dog by turning the shaft very slowly. If the detent balls will not align in the center of the ramp, withdraw the shaft slightly to clear the splines in the clutch dog, and then ° rotate the shaft 180 and the balls should align with the ramp when the splines index again. The spring will allow the detent balls to be depressed slightly and then to be held in place in the clutch dog groove. As the shaft moves into its proper place, a definite "click" sound will be heard, indicating the detent balls have "popped" into the clutch dog groove and the unit is in NEUTRAL 17-Coat the threads, and then install the Phillips screw through the outside of the lower unit housing to secure the shift lever and yoke assembly in place. This is accomplished by reaching inside the lower unit and moving the shift lever and yoke assembly to align the hole in the housing with the hole in the assembly. When the holes are aligned, install the screw and tighten it securely. MECH SHIFT 9.9 AND 15 HP 8-85 Reverse Gear Instal Ia tion 18-Insert the reverse gear into the lower uni t over the propeller shaft. Bearing Carrier Installation 19-Thoroughly lubricate the bearings in the bearing carrier with HI-VIS grease. Check to be sure the 0-ring is in place. Insert the bearing carrier into the lower unit housing. 20-Coat the threads of the attaching screws with OMC Sealant. Secure the bearing carrier in place with the screws. Tighten the screws EVENLY and ALTERNATELY to the torque value given in the Appendix. Shift Rod Adjustment 21-After installation, the bend in the shift rod must be toward the forward (leading) edge of the lower unit. Lay a straightedge over the top of the lower unit housing. Measure the distance from the straightedge to the top corner edge of the shift connector. This dimension must be between 1/16"13/ 32" (1.6-l0.3mm). To adjust, thread the shift rod into, or out of, the yoke assembly until the required dimension is obtained. the short bolts through the aft holes and the long bolts through the forward holes. Tighten the bolts EVENLY and AL TER-NA TEL Y to the torque value given in the Appendix. ALWAYS rotate the driveshaft CLOCKWISE while the screws are tightened to prevent damaging the impeller vanes. If the impeller is not rotated, the housing could the short bolts through the aft holes and the long bolts through the forward holes. Tighten the bolts EVENLY and AL TER-NA TEL Y to the torque value given in the Appendix. ALWAYS rotate the driveshaft CLOCKWISE while the screws are tightened to prevent damaging the impeller vanes. If the impeller is not rotated, the housing could 8-86 LOWER UNIT WATER PUMP INSTALLATION 22-Apply a thin bead of OMC Sealant Type-M onto the bottom side of the water pump plate where it will contact the lower unit. Slide the plate down over the drive shaft and into place on the lower unit sur face. Apply a coating of needle bearing grease in the keyway of the driveshaft. Slide the impeller down the driveshaft. Just before it covers the driveshaft keyway, in sert the key into the keyway. Slide the impeller the remaining way down the drive shaft until it seats on the water pump plate with the key indexed into the slot of the impeller. Coat the inside surfaces of the water pump housing with light-weight oil. Lower the water pump housing down the dr iveshaft over the impeller and onto the water pump plate. Rotate the driveshaft CLOCKWISE while lowering the water pump housing to allow the impeller blades to enter and to assume their natural and proper position inside the housing. Continue to rotate the driveshaft and work the water pump housing downward until it is seated on the water pump plate. 23-Coat the threads of the water pump attaching bolts with OMC Sealant. Install VATER PUMP HOUS ING damage or cut the end of the vanes as the screws are brought up tight. The rotation allows them to spring back in a natural position. 24-Place NEW grommets into the water pump housing for the water pickup. If a new water pump was installed, these grommets will already be in place. Check to be sure the seal is in place on top of the water pump housing. Slip the 0-ring onto the end of the dr iveshaft. Filling the Lower Unit Fill the lower unit with lubricant according to the procedures in Section 8-3. Propeller Installation Install the propeller, see Section 8-2. LOWER UNIT INSTALLATION GOOD WORDS Connecting the shift rod with the connector is not an easy task but can be accomplished as follows: First, notice the cutout area on the end of the shift rod. This area permits the bol t to pass through the connector, past the shift rod, and into the other side of the connector. It is this bolt that holds the shift rod in the connector. Now, in order for the bolt to be properly installed, the cutout area on the shift rod MUST be aligned in such a manner to allow the bolt to be properly installed. Therefore, as the lower unit is mated with the exhaust housing, exercise patience as the two uni ts come together, to enable the bolt to be installed at the proper time. If the rod is allowed to move too far into the connector MECH SHIFT 9.9 AND 15 HP 8-87 grommets with lubricant as an aid to installation. Guide the lower unit up into the exhaust housing with the water tube sliding into the rubber grommet of the water pump. Continue to work the lower unit towards the exhaust housing, and at the same time rotate the propeller shaft as an aid to indexing the driveshaft splines with the crankshaft. Insert the bolt into the connector. TAKE TIME to read and understand the "Good before the bol t is installed, it may be possible to force the bolt into place, past the shift rod. The threads on the bolt will be stripped, and the shift rod will even tually come ou t of the connec tor, illustration B and C. 25-Install the connec tor onto the lower unit shift rod, wi th the NO THREAD section facing towards the starboard side of the lower unit. With the connec tor in this position, the bolt may be inserted through the connec tor and "catch" the threads on the far side. Install the connec tor bolt in the manner described in the previous paragraph. 26-Check to be sure the water pickup tubes are dean, smooth, and free of any corrosion. Coat the water pickup tubes and 8-88 LOWER UNIT Words" just before Step 25, before making this connection. Start the bolts securing the lower unit to the exhaust housing. Tighten the bolts EVENLY and ALTERNATELY to the torque value given in the Appendix. FUNCTIONAL CHECK 27-Perform a functional check of the completed work by mounting the engine in a test tank, in a body of water, or with a flush attachment connected to the lower unit. If the flush attachment is used, NEVER operate the engine above an idle speed, because the no-load condition on the propeller would allow the engine to RUNAWAY resulting in serious damage or destruction of the engine. CAUTION: Water must circulate through the lower unit to the engine any time the engine is run to prevent damage to the water pump in the lower unit. Just five seconds without water will damage the water pump. Start the engine and observe the tattletale flow of water from idle relief in the exhaust housing. The water pump installation work is verified. If a "Flushette" is connected to the lower unit, VERY LITTLE water will be visible from the idle relief port. Shift the engine into the three gears and check for smoothness of operation and satisfactory performance. 8-10 PROPELLER EXHAUST MECHANICAL SHIFT 20 HP AND 30 HP -1981 &: ON 25 HP -1986 &: ON 35 HP 1976-84 - DESCRIPTION As the name implies, the unit covered in this section is a mechanical shift, propeller exhaust lower unit. Forward, neutral, and reverse shift capabilities are incorporated. A pinion gear is splined onto the lower end of the driveshaft. This pinion gear rotates constantly while the engine is operating and drives the forward and reverse gears. A clutch dog splined to the propeller shaft is centered between the two gears when the unit is in neutral gear. A shift lever causes the clutch dog to engage either the forward or reverse gear. Power is then transferred from the direction gear through the clutch dog to the propeller shaft and propeller. TROUBLESHOOTING Troubleshooting MUST be done BEFORE the unit is removed from the exhaust hous ing, to permit isolating the problem to one area. Always attempt to proceed with troubleshooting in an orderly manner. The shotgun approach will only result in wasted time, incorrect diagnosis, replacement of unnecessary parts, and frustration. The following procedures are presented in a logical sequence with the most preva lent, easiest, and less costly items to be checked, listed first. Unable to Shift into Forward or Reverse Remove the propeller according to the procedures outlined in Section 8-2. Make a careful check of the rubber hub to deter mine if it has been slipping in the propeller. If there is any evidence the rubber has melted, or if pieces of rubber have been torn from the hub, it is a clear indication the hub has been slipping. If the check reveals the hub has been slipping, the propeller must be sent to a propeller shop with the proper equipment and trained personnel to perform the nec essary service work. Water in the Lower Unit Water in the lower unit is usually caused by fish line becoming entangled around the propeller shaft ahead of the propeller and damaging the propeller seal. If the line is not removed, it will cut the propeller shaft seal and allow water to enter the lower unit. Fish line has also been known to cut a groove in the propeller shaft. The shift rod seal may be damaged and require replacement. The seal under the water pump may be damaged and allowing water to enter the lower unit. The propeller should be removed each time the boat is hauled from the water at the end of an outing and any material entangled behind the propeller removed before it can cause extensive damage. The small amount of time and effort involved in pulling the propeller is repaid many times by reduced maintenance and service work, including the replacement of expensive parts. Slippage in the Lower Unit If the shift seems to be slipping as the boat moves through the water: First, check the propeller and the rubber hub. If the propeller has been subjected to many strikes against underwater objects, it could slip on its hub. If the hub is damaged or excessively worn on the small propellers, it is questionable whether it economical to have the hub or propeller rebuilt. Sometimes a new propeller may be purchased for less than meeting the expense of rebuilding an old worn propeller. It will pay to check it out. The rubber hub on the propeller exhaust unit was found to be slipping. A new hub is being installed. MECH SHIFT 251-P TO 351-P 8..9 Difficult Shifting Verify that the ignition switch is OFF, or better still, disconnect the spark plug wires from the plugs, to prevent possible personal injury, should the engine start. Shift the unit into REVERSE gear at the shift control box, and at the same time have an assistant turn the propeller shaft to ensure the clutch is fully engaged. If the shift handle is hard to move, the trouble may be in the lower unit, the shift cable, the handle passing through the exhaust housing, or in the shift box if one is used. To Isolate the Problem: Disconnect the shift cable, if used, at the engine. Operate the shift lever at the shift box. If shifting is still hard, the problem is in the shift cable or control box, see Chapter 7. If the shifting feels normal with the shift cable disconnected, the problem must be in the lower unit or in the area where the shift lever passes through the cowling to the bellcrank. Lack of lubrication is usually the cause of problems with the shift lever and bellcrank. To verify the problem is in the lower unit, have an assistant turn the propeller and at the same time move the shift cable back-and-forth. Determine if the clutch engages properly. Jumping Out of Gear If a loud thumping sound is heard at the transom while the boat is underway, the unit is jumping out of gear, resulting in a no-load condition on the propeller. When this happens, the rushing water under the hull forces the lower unit in a backward direction. The unit jumps back into gear; the propeller catches hold; the lower unit is forced forward again; and the result is the thumping sound as the action is repeated. Normally this type of action occurs perhaps once a day, then more frequently each time the dutch is operated, until finally the unit will not stay in gear for even a short time. The following areas must be checked to locate the cause: 1-Check the bellcrank under the powerhead. Remove the window on the port and starboard side of the lower unit. If working on a 1976-79 model, remove the window in the exhaust housing. Hold the shift rod with a pair of pliers and at the same time attempt to move the shift lever on the starboard side of the engine. If it is possible to move the shift lever, the bellcrank is damaged. 8-90 LOWER UNIT Window in a lower unit to permit access to the shift rod disconnect. Notice how the ramps face forward to allow water to enter the cooling system. If the window is not installed properly, the engine will quickly overheat from lack of cooling water, causing damage to the pump impeller and the powerhead. 2-Disconnect the shif t cable at the engine. Attempt to shift the unit into forward gear with the shift lever on the starboard side of the engine and at the same time rotate the propeller in an effort to shift into gear. Shift the control lever at the control box into forward gear. Move the shif t cable at the engine up to the shift handle and determine if the cable is properly aligned. If the inner cable should slip on the end cable guide, the adjustment would be lost. View into the exhaust housing after the power head has been removed. The shift rod bellcrank is visible. 3-!'viove the shift lever at the engine into the neutral position and the shift lever at the control box to the neutral position. Now, move the shif t cable up to the shift lever and see if it is aligned. Shift the unit into reverse at the engine and shif t the control lever at the control box into reverse. Move the cable up and see if it is aligned. If the cable is properly aligned, but the unit still jumps out of gear when the cable is connec ted, one of three conditions may exist. a-The bellcrank is worn excessively or damaged. b-The shift rod connec tor is misaligned. This connec tor is used to link the upper shift rod with the lower rod. If the connector has not been installed properly, any shifting will be difficult. c-Parts in the lower unit are worn from extended use. Frozen Powerhead This condition is suggested when the operator unsuccessfully attempts to crank the engine, either with a hand starter or Window and gasket removed from the exhaust housDetailed drawing to depict removal of the cable ing with the shift rod disconnect bolt shown. from the shift handle. with a starter motor. The flywheel will not rotate. Do not assume the engine is "frozen" until the lower unit has been removed and thoroughly checked. If the lower unit is "locked" (the driveshaft or propeller shaft will not ·rotate), the powerhead will have the indication of being "frozen" (failure to rotate the flywheel). The first step to perform under these conditions is to "pull" the lower unit, and then again attempt to crank the engine. If the attempt is successful with the lower unit disconnec ted, the problem is in the lower unit. If the attempt to crank the engine is still unsuccessful, the problem is in the powerhead. LOWER UNIT SERVICE Access to the shif t connec tor for this unit is gained by removing the window in the lower unit (models 1980 and on), or by removing the window in the exhaust housing (models 1976-79). Propeller Removal Remove the propeller according to the procedures outlined in Section 8-2. MECH SHIFT 251-P TO 35HP 8-91 Draining Lower Unit Drain the lubricant in the lower unit, see Section 8-3. GOOD WORDS If water is discovered in the lower unit and the determination is made the propeller shaft seal is damaged and requires replacement, the lower unit does NOT have to be removed in order to accomplish the work. The bearing carrier can be removed and the seal replaced without disassembling the lower unit. HOWEVER, and this is a big HOWEVER, such a procedure is not considered good shop practice, but merely a quickfix. If water has entered the lower unit, the unit should be disassembled and a detailed check made to de termine if any other seals, bearings, bearing races, 0-rings or other parts have been rendered unfit for further service by the wa ter. LOWER UNIT REMOVAL 1-Disconnect the spark plug wires from the spark plugs. Remove the port and starboard water inlet screens, below the anti-cavitation plate. After the screens have been removed, the shift rod connection will be visible inside the lower unit. Notice the two nu ts on the shift rod. Use two wrenches and loosen the top nut. Back off the upper nut on to the upper portion of the shift rod. 2-Work a knife or similar tool into the split of the black plastic keeper and remove the keeper from the upper shift rod. Shift the unit into forward gear, and then remove the nut from the upper shift rod. Damaged pistons in a "frozen" powerhead. If the shift problem is isolated to the powerhead, the lower unit need not be disassembled. 8-92 LOWER UNIT 3-If servicing a 1 $76-7.. model, remove the window in the exhaust housing and then remove the bottom screw from the shift connector. The shift rod will then be discormecteC: when the lower unit is separated from the exhaust housing. 4-Remove the forward nut and two bolts, one on each side of the lower unit, securing the unit to the exhaust housing. 5-Separate the lower unit straight away from the exhaust housing. TAKE CARE not to twist or pull backward, sideways, etc., when removing the lower unit, because the driveshaft may be bent. If there is restricted clearance between the bottom of the lower unit and the floor, tilt the complete unit forward in order to gain the necessary room for the lower unit to clear. 6-Position the lower unit in a vertical position on the edge of the work bench resting on the cavitation plate. Secure the lower unit in this position with a C-clamp. The lower unit will then be held firmly in a favorable position for further service work. An alternate method is to cut a groove in a short piece of 2" x 6" wood to accommodate the lower unit with the cavitation plate resting on top of the wood. Clamp the wood in a vise and service work may then be performed with the lower unit erect (in its normal position), or inverted (upside down). In both positions, the cavitation plate is the supporting surface. WATER PUMP REMOVAL ADVICE If the only work to be performed is service of the water pump, be extremely CAREFUL to prevent the driveshaft from being pulled up and free of the pinion gear in the lower unit. NEVER carry the lower unit by the driveshaft or by the shift rod. If the shaft should be released from the pinion gear, the lower unit MUST be disassembled to align the pinion gear and driveshaft, then the driveshaft installed. 7-Remove the bolts securing the water pump housing to the lower unit. Slide the water pump housing up and free of the driveshaft. Remove the water pump impeller and key from the driveshaft. Remove the long spacer and bushing from the pump housing. Slide the gasket, pump plate, and second gasket, up and free of the driveshaft. Discard the gaskets. New gaskets are included in a water pump repair kit. GOOD WORDS If the only work to be performed is service of the water pump, proceed directly to Page 8-110, Water Pump Installation. LOWER UNIT DISASSEMBLING 8-Grasp the driveshaft firmly and withdraw it from the lower unit. MECH SHIFT 251-P TO 351-P 8-93 Bearing Carrier Removal 9-Use a thin-wall socket and remove the bolts securing the bearing carrier in the lower unit. SPECIAL WORDS Two methods are available to pull the bearing carrier from the lower unit. One method involves the use of a flywheel puller and a couple of bolts. The second method requires the use of a special OMC puller and 8-94 LOWER UNIT a couple bolts. Both methods are described in the following step. If the bearing carrier is stubborn and refuses to budge, apply heat to the outside surface of the lower unit while taking up on either type of puller. TAKE CARE not to overheat the lower unit. Aluminum will start to bubble at a relatively low temperature. 10-Obtain an OMC flywheel puller and two 1/4" x 20 bolts. Thread the bolts into the bearing carrier opposite one another. Take up on the center nut of the puller and pull the bearing carrier free of the lower unit. The second method involves the use of a special puller tool, OMC No. 378103 and two long 1/4" x 20 bolts. Thread the bolts into the bearing carrier. Use the special puller to remove the bearing carrier, as shown in the accompanying illustration "A11• WARNING The next step involves a dangerous procedure and should be executed with care while wearing SAFETY GLASSES. The retaining ring is under tremendous tension in the groove and while it is being removed. If it should slip off the Truarc pliers, it will travel with incredible speed causing personal injury if it should strike a person. Therefore, continue to hold the ring and pliers firm after the ring is out of the groove and clear of the lower unit. Place the ring on the floor and hold it securely with one foot before releasing the grip on the pliers. An alternate method is to hold the ring inside a trash barrel, or other suitable container, before releasing the pliers. 11-Obtain a pair of Truarc pliers. Insert the tips of the pliers into the holes of LATE MODEL LOWER SH IFT ROD LATE MODEL LOWER SH IFT ROD the retammg ring. Now, CAREFULLY remove the retaining ring from the groove and gear case without allowing the pliers to slip. Release the grip on the pliers in the manner described in the above WARNING. Remove the retainer plate. As the plate is removed, notice which surface is facing into the housing, as an aid during installation. 12-If servicing a 1980 or la ter model, use the proper size wrench extended through the window of the lower unit, and back the shift rod out of the shift yoke by rotating it COUNTERCLOCKWISE until it is free. 13-If servicing a 1976-79 model, simply back the shift rod out COUNTERCLOCKWISE until it is free of the housing. 14-Using a pair of needle-nose pliers, reach in, grasp the shift yoke, and slide it back off the propeller shaft. NOW THESE WORDS A hole is drilled through the propeller shaft just forward of the reverse gear. A detent spring is installed in the hole along with a detent ball on each side of the propeller shaft. The clu tch dog is ins tailed over the top of the two detent balls. This arrangement assists in holding the unit in the specific gear desired. When the bearing carrier, propeller shaft, and associated parts are removed, the clutch dog will remain in the lower unit. As soon as the dutch dog slides free of the propeller shaft, the detent balls and spring ® MECH SHIFT 251-P TO 35HP 8-95 will fly free of the shaft, but will be contained within the lower unit housing. Therefore, after the propeller shaft, bearing carrier, etc., are removed (next step) take time to retrieve the two detent balls and the spring from inside the lower unit. Propeller Shaft --Removal 15-Remove the Phillips screw from the outside of the lower unit. This is the screw securing the shift lever in place and is located close to the lubricant drain plug. 8-96 LOWER UNIT 16-After the screw has been removed, grasp the propeller shaft firmly and withdraw it from the lower unit. The reverse gear, clutch dog, cradle, and associated parts will come out with the shaft. If these parts fail to come out with the shaft, reach in and remove them one at-a-time. Remember the two detent balls and the detent spring. 17-Remove the pinion gear, two thrust washers, and thrust bearing. Take time to notice the arrangement of the two thrust washers and the bearing. Notice how one thrust washer is beveled on the inside diameter and the other is beveled on the outside diameter. It is extremely important that these washers and the thrust bearing are installed properly. 18-Reach in and remove the forward gear. TAKE CARE not to lose the thrust washer installed in the inside diameter of the forward gear. 19-Remove the forward gear tapered bearing from the lower unit. Upper Driveshaft Seals -Removal 20-Use a slide hammer with external jaws. Fit the jaws down inside the seals, and then operate the slide hammer to remove the seals. Notice how the seals were installed back-to-back (flat side against flat side). ME CH SHIFT 251-P TO 351-P 8-97 VERY CRITICAL WORDS The upper driveshaft bearing, the pm10n gear bearing, and the forward gear bearing race NEED NOT be removed unless they are unfit for further service. These bearings, especially the pinion gear bearing, can only be installed using special OMC tools. Even with the tools, the task is not an easy one. Therefore, determine their condition by first checking with a flashlight for signs of corrosion or damage, and then by inserting a finger into the bearing and rotating it while checking for "rough" spots or binding. If they appear to be in satisfactory condition, "let a sleeping dog lie." Continue with the other work. Upper Driveshaft Bearing -Removal 21-The upper driveshaft bearing is housed in a sleeve. If the bearing is to be removed, first punch out the bearing downward into the housing. Use special tool OMC No. 391010, and remove the bearing sleeve from the housing. Turn the lower unit upside down and the upper driveshaft bearing will fall free. Pinion Gear Bearing -Removal 22-Use any type of punch to drive the bearing free. Further damage to the bearing is of no concern because it is being removed due to its unfitness for further service. 8-98 LOWER UNIT Forward Gear Bearing Race -Removal 23-Use a slide hammer equipped with fingers and "pull" the race from the housing. Shift Rod 0-ring and Bushing -Removal 24-Insert a length of 1/4" rod, with threads on both ends, down through the 0ring and bushing. Thread a nut onto the lower end of the rod. (The edges of the nut must be first rounded to permit the nut to pass through the opening in the housing.)Attach a slide hammer to the rod and "pull" the 0-ring, bushing and washer. SHIFT BUSH ING Bearing Carrier Seals -Removal 25-Use a puller with two fingers and work the puller down into the seals. Take up on the puller and remove the seals. Notice how the seals are installed back-toback. They must be installed in this manner to provide a proper seal to prevent the lubricant in the lower unit from escaping and water from entering. MECH SHIFT 251-P TO 35HP 8-99 An alternate method to remove the seal is to wedge a heavy duty screwdriver underneath the seal, and then to pull back on the bearing carrier, as shown, illustration ''B"'. The seal will pop out. Repeat the procedure for the second seal. Bearing Carrier Bearing -Removal The bearings in the bearing carrier need NOT be removed unless they are unfit for further service. Check their condition for damage and corrosion. Insert a finger inside and rotate the bearing while checking for roughness or any sign of binding. Check for evidence of corrosion. 26-Use a slide hammer with fingers and remove the bearings outward from the carrier. An alternate method is to use a punch and drive the bearing free of the carrier, illustration "C". If the bearing is damaged and no longer fit for service, further damage will be of no consequence. CLEANING AND INSPECTING Clean all water pump parts with solvent, and then dry them with compressed air. Inspect the water pump cover and base for cracks and distortion, possibly caused from overheating. Inspect the face plate and water pump insert for grooves and/or rough surfaces. If possible, ALWAYS install a complete new water pump while the lower unit is disassembled. A new impeller will ensure extended satisfactory service and 8-100 LOWER UNIT give "peace of mind" to the owner. If the old impeller must be returned to service, NEVER install it in reverse to the original direction of rotation. Installation in reverse will caus.. premature impeller failure. Inspect the impeller side seal surfaces and the ends of the impeller blades for cracks, tears, and wear. Check for a glazed or melted appearance, caused from operating without sufficient water. If any question exists, and as previously stated, install a new impeller if at all possible. Clean all parts with solvent and dry them with compressed air. DISCARD all 0rings and gaskets. Inspect and replace the driveshaft if the splines are worn. Inspect the gearcase and exhaust housing for damage to the machined surfaces. Remove any nicks and refurbish the surfaces on a surface plate. Start with a No. 120 Emery paper and finish with No. 180. Check the water intake screen and passages by removing the bypass cover, if one is used. Inspect the clutch dog, drive gears, pinion gear, and thrust washers. Replace these items if they appear worn. If the clutch dog and drive gear arrangement surfaces are nicked, chipped, or the edges rounded, the operator may be performing the shift operation improperly or the controls may not be adjusted correctly. These i terns MUST be replaced if they are damaged. Inspect the dog ears on the inside of the forward and reverse gears. The gears must be replaced if they are damaged. Check the cradle that rides on the inside diameter of the clutch dog. The sides of the cradle must be in good condition, free of New clutch dog and gear. Compare these two parts with those shown at the bottom of the previous column. any damage or signs of wear. If damage or wear has occurred, the cradle must be replaced. Check the shift lever and the two prongs that fit inside the cradle. Check to be sure the prongs are not worn or rounded. Damage or wear to the prongs indicates the lever must be replaced. LOWER UNIT ASSEMBLING READ AND BELIEVE The lower unit should NOT be assembled in a dry condition. Coat all internal parts with OMC HI-VIS lube oil as they are assembled. All seals should be coated with OMC Gasket Seal Compound. When two seals are installed back-to-back, use Triple Guard Grease between the seal surfaces. A rusted and corroded gear. Water was allowed to The ears on this clutch dog and the teeth on the enter the lower unit through a badly worn seal and gear are badly worn. Both items are unfit for further cause this damage to the gear and other expensive service. parts. Q /1 MECH SHIFT 25 H' TO 351-P 8-101 GASKET I I I ROD . 'u' / ) I HPELLER I PIN 1.-/ BEARING HOUS ING ..Q PINION // // // BEARING ---/ " PIVOT PIN i t-.: .fP -- -- {!}.{ - REVERSE GEAR i I PROPELLER PINION FORWARD ·. THRUST WASHER \ :I ' .. THRUST CRADLE ' BEARING SH IFT LEVER . 30hp and 35hp ' lower um"t with maJor pa 8-102 LOWER UNIT A set of double seals showing the back side (left) and the front side (right). These seals are installed back-to-back (flat side-to-flat side) with Triple Guard Grease between the surfaces. This arrangement prevents fluid from passing in either direction. Bearing Carrier Bearings -Installation 1-Obtain special tool OMC NO. 321429. Place the bearing in position with the lettered side of the bearing facing UP. Press against the lettered side of the forward bearing, using the special tool and an arbor press. Turn the bearing carrier end-for-end and press the other bearing into place in the same manner, using the arbor press and special tool OMC No. 321428. ALWAYS press against the lettered side of the bearing. 2-The two bearing carrier seals are installed back-to-back. The inner seal prevents the lower unit lubricant from escaping, and the outer seal prevents water from entering the lower unit. Coat the outside surfaces of the seals with seal compound flat side facing UP. Coat the flat side of the installed seal and the flat side of the second seal with Triple Guard Grease. Install the second seal with the flat side facing DOWN. After installation, the lip of the second seal should be flush with the surface of the bearing carrier. and press the first seal into place with the 3-Check to be sure the 0-ring groove of the bearing carrier is clean. Coat the 0ring with OMC HI-VIS lube oil and then install it into the groove. Set the bearing carrier aside for Ia ter installation. Forward Gear Bearing Race --Installation 4-If the forward gear bearing race was removed, install a new race by first coating the race wi th OMC HI-VIS lube oil. Obtain special tool, OMC No. 319929 and driver handle, OMC No. 31 1880. Drive the race into place squarely. Shift Rod Bushing and 0-ring -Installation 5-For the 1980 and later models: Obtain special tool, OMC No. 304515. Install the washer and then the 0-ring. Install the bushing using the special tool. If the special tool is not available, a tool the same size as the outside diameter as the bushing may be used to drive the bushing into place. The bushing does not go in hard. TAKE CARE not to distort the inside diameter of the bushing. GOOD WORDS Two different lower units have been used with the late model 3.5 hp lower uni ts from 1976. Changes in the assembling procedures for these two units is clearly indica ted in the following steps. Pinion Gear Bearing -Installation 6-Special tool OMC No. 391257 is required to install this bearing. Assemble the MECH SHIFT 251-P TO 35HP 8-103 tool, as shown in the accompanying illustration. Drive the bearing into place from the top until the plate of the tool makes contact with the lower unit. The bearing will then be installed to the proper depth in the lower unit. For 1976 models ONLY: Special tool OMC No. 321516 and No. 318122 are required to install the bearing. Use a flat washer and a 1/2" x 13 x 1" screw from tool, OMC No. 316910. Drive the bearing into place with the lettered side facing the tool. HEX HEAD SCREW PI LOT PlATE . INSTAllER REMOVER HE D SCREW CD 8-104 LOWER UNIT Upper Driveshaft Bearing -Installation 7-Obtain special tool, OMC No. 322923. Press the bearing into the bearing retainer with the lettered side of the bearing facing the tool. Press the assembled bearing and retainer into the lower unit housing until it seats. A socket the same size as the outside diameter of the retainer may be used. TAKE CARE not to damage the bearing during installation. For 1976 model ONLY: When the bear ing is purchased, the bearing is installed in the retainer. If the bearing retainer was not removed, press the bearing into the retainer in the housing. Press the bearing with the lettered side facing the tool, until the bot tom of the bearing is flush with the bottom of the retainer, illustration "An. Driveshaft Seals -Installation 8-These seals are installed back-toback, flat side-to-flat side, illustration ''Bn. The inner seal prevents the lower unit lubricant from escaping, and the outer seal prevents water from entering the lower unit. Coat the outside surface of the first seal with Seal Compound. Install the seal with the flat side facing UP. Coat the flat side of the installed seal and the flat side of the second seal with Triple Guard Grease. Install the second seal with the flat side facing DOWN. Forward Gear Bearing -Installation 9-Insert the bearing into the race with the tapered side of the bearing going in FIRST. MECH SHIFT 251-P TO 351-P 8-105 Pinion Gear -Installation 10-Install the thin thrust washer onto the pinion gear shank with the bevel on the inside diam eter facing DOWN. 11-Slide the thrust bearing onto the shank. 12-Slide the thick second washer onto the pinion gear shank with the bevel facing UP. 13-Insert the assembled pinion gear into the opening in the lower unit housing. Forward Gear --Installation 14-Insert the thrust washer into the forward gear. Lower the forward gear down into the lower unit housing past the pinion gear. By tilting the gear slightly it will pass the pinion gear. The teeth of the forward gear must index with the teeth of the pinion gear. Shift Mechanism -Installation 15-Lower the shift lever into the lower unit housing and into place in the recess. Propeller Shaft -Installation VERY VERY GOOD WORDS Two illustrations accompany most of the next 10 steps. One set is numbered and is 8-106 LOWER UNIT the same as the step number. The other set has a letter identification. NOW, the numbered illustrations show the work being performed in the normal manner with the lower unit. The lettered illustrations show the work being performed on a work bench in order to give you a clear understanding of what is happening and the relationship of the parts inside the lower unit. 16-Insert the detent spring through the hole in the propeller shaft. Apply a small amount of needle bearing grease to the hole on both sides of the propelier shaft. Stick a detent ball into place in the grease on each side of the shaft. Slide the clutch dog down the propeller shaft with the cu tou ts aligned with the two detent balls. If the cutouts do not align with the detent balls, withdraw the ° clutch dog, rotate it 180 , and then slide it back onto the shaft, reference illustration "C". Notice the small groove on the outside diameter on one side of the clutch dog. This groove MUST face the forward gear. Carefully slide the clutch dog over the two de tent balls and into the neutral posi tion on the shaft. 17-Lubricate the large groove in the clutch dog with needle bearing grease, reference illustration "D". This illustration will be helpful in understanding the relationship of the forward gear, forward gear bear ing, and the shift lever. Notice how the shaft passes over the top of the shif t lever. Slide MECH SHIFT 251--P TO 35HP 8-107 the cra.fle into the large groove of the clutch dog. Insert the assembled propeller shaft into the lower unit, with the forward end of the shaft indexed into the forward gear and forward gear bearing. At the same time, the shaft is worked over the top of the shift lever. 18-Slide a screwdriver blade under the shift lever and work the fork fingers up into the cradle, reference illustration "E". 19-After the fingers are in place in the cradle, move the shift lever until the hole in the lever is aligned with the hole in the lower unit housing, reference illustration "F". When the holes align, start the Phillips screw through the housing and into the lev er. Apply a coating of OMC onto the threads of the screw. screw securely. 1000 Tighten the sealer Reverse Gear -Installation 20-Insert the thrust washer into the reverse gear. Slide the reverse gear down the propeller shaft into the lower unit housing. 8-108 LOWER UNIT 21-Slide the shift yoke down the propeller shaft and hook it into the shift lever, reference illusta tion 11G". 22-On the 1980 and later models: Coat the shift rod with light-weight oil and then insert the shift rod down through the 0-ring and thread it into the shif t yoke. Tighten the shift rod securely in the yoke, with a wrench, reference illusta tion 11H11• On the 1 976-79 models: Thread the shift rod in to the shift yoke with the bend in the rod facing the driveshaft, reference illustration 11l11• Bearing Carrier -lnstalla tion 23-Slide the retainer plate onto the propeller shaft and against the lower unit housing, with the lip of the plate indexed into the short slot on the bottom side of the lower unit, reference illustration "K". lOWER SHIFT ROD LATE MODELS @ MECH SHIFT 25.. TO 35.. 8-109 WARNING This next step can be dangerous. The snap ring is placed under tremendous tension with the Truarc pliers while it is being placed into the groove. Therefore, wear SAFETY GLASSES and exercise care to prevent the snap ring from slipping out of the pliers. If the snap ring should slip out, it would travel with incredible speed and cause personal injury if it struck a person. 24-Use a pair of Truarc pliers and install the Truarc snap ring into the groove in the lower unit, next to the retainer plate. Check to be sure the ring is properly seated all the way around in the groove. 25-Obtain two 1/4-" rods about 12" long with 1/4-x 28 threads on one end. Thread these two rods into the retainer plate to act @ 8-1 10 LOWER UNIT as guides for installation of the bearing carrier. Observe the word UP embossed into the metal of the bearing carrier rim, reference illustration "L". Slide the bearing carrier onto the propeller shaft over the guide rods and into the lower unit, with the word UP facing UPWARD in relation to the lower unit housing. Check to be sure the thrust washer is seated in the recess of the bearing carrier towards the reverse gear. 26-Slide new 0-rings onto the bearing carrier bolts. Coat the threads of the bolts with OMC Sealer. Install two bolts through the bearing carrier and into the retainer. Back out the two guide rods used to install the bearing carrier. Install and tighten the bearing carrier bolts securely to the torque value given in the Appendix. Driveshaft -Installation 27-Install the guide bushing down over the stud on top of the housing, as shown. 28-Apply sealer to the upper housing surface. 29-Coat the driveshaft with lightweight oil as an aid to installation. Slide the dr iveshaft down into the lower unit. As the driveshaft is lowered, rotate the driveshaft slightly to permit the splines on the shaft to index with the splines of the pinion gear. WATER PUMP INSTALLATION 30-Slide a NEW water pump gasket down the driveshaft and into place on the housing. Coat the upper surface of the gasket with sealer. Slide the water pump plate down the driveshaft and into place on top of the gasket. Check to be sure the small driveshaft grommet that seats in the plate and through the gaskets is installed with the small side facing UP. Coat both sides of a NEW second water pump gasket with sealer, and then slide it down the driveshaft and into place on top of the water pump plate. Check to be sure the MECH SHIFT 251-P TO 351-JP 8-1 11 driveshaft slowly CLOCKWISE as the housholes in both gaskets, the plate, and in the housing are aligned. If the holes do not align, one of the gaskets or the plate is upside down. Correct the error. 31 -Slide the water pump impeller down the dr iveshaft. Just before the impeller covers the cutout for the impeller pin, install the pin. Align the slot in the impeller with the impeller pin, and then continue to work the impeller down the dr iveshaf t until it is firmly in place on the surface of the upper water pump gasket. 32-Check to be sure NEW seals and 0rings have been installed in the water pump. Lubr lea te the inside surface of the water ing is lowered over the impeller to allow the impeller ':>lades to assume their natural and proper position inside the housing. Continue to rotate the driveshaft and work the water pump housing downward until it is seated on the gasket and pia te. 33-Coat the threads of the water pump attaching bolts with sealer, and then secure the pump in place with the bolts. Tighten the bol ts AL TERNA TEL Y and EVENLY. Check to be sure a NEW grommet has been installed in the top of the water pump. Install a NEW 0-ring onto the top of the driveshaft. pump with ligh t-weight oil. Lower the water pump housing down the driveshaft and over the impeller. ALWAYS rotate the 8-1 12 LOWER UNIT LOWER UNIT INSTALLATION GOOD WORDS 1976 thru 1979 Models ONLY Connecting the shift rod with the connector is not an easy task but can be accomplished as follows: First, notice the cutout area on the end of the shift rod. This area permits the bolt to pass through the connector, past the shift rod, and into the other side of the connector. It is this bolt that holds the shift rod in the connector. Now, in order for the bolt to be properly installed, the cutout area on the shift rod MUST be aligned in such a manner to allow the bolt to be properly installed. Therefore, as the lower unit is rna ted with the exhaust hou sing, exercise patience as the two units come together, to enable the bolt to be installed at the proper time. If the rod is allowed to move too far into the connector before the bolt is installed, it may be possible to force the bolt into place, past the shift rod. The threads on the bolt will be stripped, and the shift rod will eventually come out of the connector, illustration "M" and "N". 34-Install the connector onto the lower unit shift rod, with the NO THREAD section facing towards the window. With the connector in this position, the bolt may be inserted through the connector and "catch" the threads on the far side. Install the connector bolt in the manner described in the previous paragraph. For All Models 35-Check to be sure the water tubes are clean, smooth, and free of any corrosion. Coat the water pickup tubes and grommets with lubricant as an aid to installation. Check to be sure the spark plug wires are disconnected from the spark plugs. Bring the lower unit housing together with the exhaust housing, and at the same time, guide the water tube into the rubber grommet of the water pump. As the two units MECH SHIFT 25f-P TO 351-P 8-1 13 come together, rotate the flywheel slowly to permit the splines of the driveshaft to index with the splines of the crankshaft. 36-After the surfaces of the lower unit and exhaust housing make contact, start the nut on the stud on the leading edge of the lower unit. Start the four bolts on the bottom side of the lower unit. DO NOT tigh ten this hardware at this time. For the 1976 thru 1979 Models ONLY The shift connec tion is made through the window in the exhaust housing. 37-Insert the bolt into the connector. TAKE TIME to read and understand the "Good Words" just before Step 34, before making this connec tion. After the bolt is in place, install and secure the window with the attaching hardware. Tighten the bolts and the nut securing the lower unit to the exhaust housing AL TERNA TEL Y and EVENLY to the torque value given in the Appendix. Install the outer plate and gasket to the exhaust housing. For Models since 1980 The shif t connection is made through the water pickup openings in the lower unit. 38-At the power head, move the shift lever to the FORWARD gear position. Slip the upper shift lever nut upward, and then snap the keeper on to the end of the shift 8-1 14 LOWER UNIT rod. Move the shift lever to the REVERSE gear position. Lower the shift rod into the lower unit shift rod section. Tighten the nut to secure the lower portion of the shift rod to the upper portion. 39-Install and secure the two water pickup windows in place, with the cutout slots facing FORWARD. Filling the Lower Unit Fill the lower unit with lubricant according to the procedures in Section 8-3. Propeller Installation Install the propeller, see Section 8-2. FUNCTIONAL CHECK Per form a func tiona! check of the completed work by mounting the engine in a test tank, in a body of water, or with a flush attachment connected to the lower unit. If the flush attachment is used, NEVER operate the engine above an idle speed, because the no-load condition on the propeller would allow the engine to RUNAWAY resul ting in serious damage or destruction of the engine. CAUTION: Water must circulate through the lower unit to the engine any time the engine is run to prevent damage to the water pump in the lower unit. Just five seconds without water will damage the water pump. Start the engine and observe the tattletale flow of water from idle relief in the exhaust housing. The water pump installation work is verified. If a "Flushette" is connected to the lower unit, VERY LITTLE water will be visible from the idle relief port. Shift the engine into the three gears and check for smoothness of operation and satisfactory performance. 8-11 ELECTRIC SHIFT TWO SOLENOIDS 50 HP 1971-72 DESCRIPTION The lower unit covered in this section is a three shift position, hydraulic activated, solenoid controlled, propeller exhaust unit. A hydraulic pump mounted in the forward portion of the lower unit provides the force required to shift the unit. Two solenoids installed in the lower unit, above the pump, control and operate the pump valve. The pump valve directs the hydraulic force to place the clutch dog in the desired position for neutral, forward, or reverse gear position. One solenoid controls the valve for the neutral position. Both solenoids control the valve for the reverse position. When Cut-a-way view of a complete lower unit prior to disassembling. This type illustration is most helpful in gaining an appreciation of the internal parts and their relationship to one another. neither solenoid is activated, the unit is at rest in the forward gear position. In simple terms, something must be done (a solenoid activated and hydraulic pressure applied) to move the unit into neutral or reverse gear position. If no action is taken (shift mechanism at rest) the unit is in the forward gear position. A full 12-volts is required to activate the solenoids. This means shifting is not possible if the battery should become low for any number of reasons. A potentially dangerous condition could exist because the unit could not be taken out of forward gear. Therefore, the only way to stop forward boat movement would be to shut the engine down. A low battery would also mean the electric starter motor would fail to crank the engine properly for engine start. Such a condition would require hand starting in an emergency, if a second battery were not available. The lower unit houses the driveshaft and pinion gear, the forward and reverse driven gears, the propeller shaft, clutch dog, hy draulic pump, two solenoids, and the neces sary shims, bearings, and associated parts to make it all work properly. ONE MORE WORD A useful piece of information to remember is that the green wire carries current for the neutral position; and the green and blue wires carry current for the reverse gear operation. TROUBLESHOOTING Preliminary Checks Whenever the lower unit fails to shift properly the first place to check is the condition of the battery. Determine if the battery contains a full charge. Check the condition of the battery terminals, the battery leads to the engine, and the electrical connections. The second area to check is the quantity and quality of the lubricant in the lower unit. If the lubricant level is low, contaminated with water, or is broken down because of overuse, the shift mechanism may be affected. Water in the lower unit is VERY BAD NEWS for a number of reasons, particularly when the lower unit contains electrical or hydraulic components. Electrical parts short out and hydraulic units will not function with water in the system. ELECTRIC SHIFT 8-1 15 BEFORE making any tests, remove the propeller, see Section 8-2. Check the propeller carefully to determine if the hub has been slipping and giving a false indication the unit is not in gear. If there is any doubt, the propeller should be taken to a shop properly equipped for testing, before the time and expense of disassembling the lower unit is undertaken. The expense of the propeller testing and possible rebuild is justified. The following troubleshooting procedures are presented on the assumption the battery, including its connections, the lower unit lubricant, and the propeller have all been checked and found to be satisfactory. Lower Unit Locked Determine if the problem is in the power head or in the lower unit. Attempt to rotate the flywheel. If the flywheel can be moved even slightly in either direction, the problem is most likely in the lower unit. If it is not possible to rotate the flywheel, the problem is a "frozen" powerhead. To absolutely verify the powerhead is "frozen", separate the lower unit from the exhaust housing and then again attempt to rotate the flywheel. If the attempt is successful, the problem is definitely in the lower unit. If the attempt to rotate the flywheel, with the lower unit removed, still fails, a "frozen" powerhead is verified. A "frozen" powerhead with burned pistons. 8-1 16 LOWER UNIT Unit Fails to Shift Neutral, Forward, or Reverse Disconnect the green and blue electrical wires from the lower unit at the engine. Voltmeter Tests Separate the green and blue wires at the engine by first sliding the sleeve back, and then making the disconnect. Connect one lead of the voltmeter to the green wire to the control panel and the other lead to a good ground on the engine. Turn the ignition key to the ON position. With the shift box handle in the forward position, the voltmeter should indicate NO voltage. Move the test lead from the green wire to the blue wire to the control panel. With the shift lever still in the forward position, the voltmeter should indicate NO voltage. Move the shift lever to the NEUTRAL posi tion. With the voltmeter still connected to the blue wire, NO voltage should be indicated. Move the test lead to the green wire. Voltage SHOULD be indicated. Move the shift lever to the REVERSE position. Voltage SHOULD be indicated on the green wire AND on the blue wire, reference illustration "A". If the desired results are not obtained on any of these tests, the problem is in the shift box swi tch or the wiring under the control panel. See Chapter 7. Ohmmeter Tests Set the ohmmeter to the low scale. Connect one lead to the green wire to the lower unit, and the other lead to a good ground. The meter should indicate 5 to 7 ohms. Connec t the meter to the blue wire to the lower unit and ground. The meter should again indicate from 5 to 7 ohms, reference ill us tra tion ''B". BAD NEWS If the unit fails the voltmeter and ohmmeter tests just outlined, the only course of action is to disassemble the lower unit to determine and correct the problem. LOWER UNIT SERVICE Propeller Removal If the propeller was not removed, as directed for the troubleshooting, remove it now, according to the procedures outlined in Section 8-2. Draining the Lower Unit Drain the lower unit of lubricant, see Section 8-3. GOOD WORDS If water is discovered in the lower unit and the propeller shaft seal is damaged and requires replacement, the lower unit does NOT have to be removed in order to accom plish the work. The bearing carrier can be removed and the seal replaced without disassembling the lower unit. HOWEVER such a procedure is ., not considered good shop practice, but merely a quick-fix. If water has entered the lower unit, the unit should be disassembled and a detailed check made to determine if any other seals, bearings, bearing races, 0rings or other parts have been rendered unfit for further service by the water. LOWER UNIT REMOVAL 1-Disconnect and ground the spark plug wires. Slide back the insulators on the shift wires at the engine. Disconnect the blue wire from the blue and the green wire from the green, at the engine. HELPFUL WORD Obtain a piece of electrical wire, about 5 ft. long. Connect one end to the green wire and the other end to the blue wire. Tape the connections. Now, when the lower unit is separated from the exhaust housing, the ends of the wire will feed down through the exhaust housing. When the lower unit is free, disconnect the wire ends from the blue and green wires and leave the wire loop in the exhaust housing. When it is time to ELECTRIC SHIFT 8-1 17 bring the lower unit together with the exhaust housing, the wire ends will be connected again and the blue and green wires easily pulled back up through the exhaust housing. No sweat! Alright, on with the work. 2-Scribe a mark on the trim tab and a matching mark on the lower unit to ensure the trim tab will installed in the same position from which i.t is removed. Remove the attaching hardware, and then remove the trim tab. 3-Use a 1/2" socket with a short extension and the bolt from inside the remove 8-118 LOWER UNIT trim tab cavity. Remove the 5/8" countersunk bolt located just ahead of the trim tab position. 4-Remove the four 9/16" bolts, two on each side, securing the lower unit to the exhaust no using. Work the lower unit free of the exhaust housing. If the unit is still mounted on a boat, tilt the engine forward to gain clearance between the lower unit and the deck (floor, ground, whatever). EXERCISE CARE to withdraw the lower unit straight away from the exhaust housing to prevent bending the driveshaft. Once the lower unit is free of the exhaust housing, stop and disconnect the wires installed as described in the "Helpful Word" following Step 1. Leave the wire loop in the exhaust housing as an aid during installation. WATER PUMP REMOVAL 5-Position the lower unit in the vertical position on the edge of the work bench resting on the cavitation plate. Secure the lower unit in this position with a C-clamp. The lower unit will then be held firmly in a favorable position during the service work. An alternate method is to cut a groove in a short piece of 2" x 6" wood to accommodate the lower unit with the cavitation plate resting on top of the wood. Clamp the wood in a vise and service work may then be performed with the lower unit erect (in its normal position), or inverted (upside down). In both positions, the cavitation plate is the supporting surface. TAKE TIME Take time to notice how the shift wires are routed and anchored in position with a clamp on top of the water pump. It is extremely important for the shift wires to be routed and secured in the same position during installation, reference illustration "C". 6-Remove the 0-ring from the top of the driveshaft. Remove the bolts securing the water pump to the lower unit housing and the clamp securing the shift wires in place. Leave the clamp on the shift cable as an aid during installation. Pull the water pump housing up and free of the driveshaft. ELECTRIC SHIFT 8-1 19 7-Slide the water pump impeller up and free of the driveshaft. Pop the impeller Woodruff key out of the driveshaft keyway. Slide the water pump base plate up and off of the driveshaft. GOOD WORDS If the only work to be performed is service of the water pump, proceed directly to Page 8-137, Water Pump Installation. Shift Solenoid -Removal 8-Remove the shift solenoid cover located just aft of the water pump position. Take care not to lose the wavy washer installed under the cover. Grasp the upper (green) shift solenoid and withdraw the solenoids and shift rod from the lower unit cavity as an assembly. Bearing Carrier -Removal 9-Remove the four 5/16" bolts from inside the bearing carrier. Notice how each bolt has an 0-ring seal. These 0-rings should be replaced each time the bolts are removed. Also observe the word UP embossed into the metal rim of some bearing carriers. This word must face UP in relation to the lower unit during installation. Clean the surface and if the word "UP" does not show, the position of the carrier during installation is not important. 10-Remove the bearing carrier using one of the methods described in the following paragraphs, under Special Words. SPECIAL WORDS Several models of bearing carriers are used on the lower units covered in this section. The bearing carriers are a very tight fit into the lower unit opening. Therefore, it is not uncommon to apply heat to the outside surface of the lower unit with a torch, at the same time the puller is being worked to remove the carrier. TAKE CARE not to overheat the lower unit. One model carrier has two threaded holes on the end of the carrier. These threads permit the installation of two long bolts. These bolts will then allow the use of a flywheel puller to remove the bearing carrier, illustration 10. 8-120 LOWER UNIT Another model does not have the threaded screw holes. To remove this type bearing carrier, a special puller with arms must be used. The arms are hooked onto the carrier web area, and then the carrier removed, reference· illustration ''D'"'. WARNING The next step involves a dangerous procedure and should be executed with care while wearing SAFETY GLASSES. The retaining rings are under trem en do us tension in the groove and while they are being removed. If a ring should slip off the Truarc pliers, it will travel with incredible speed causing personal injury if it should strike a person. Therefore, continue to hold the ring and pliers firm after the ring is out of the groove and clear of the lower unit. Place the ring on the floor and hold it securely with one foot before releasing the grip on the pliers. An alternate method is to hold the ring inside a trash barrel, or other suitable container, before releasing the pliers. 11-Obtain a pair of Truarc pliers. Insert the tips of the pliers into the holes of the first retaining ring. Now, CAREFULLY remove the retaining ring from the groove and gear case without allowing the pliers to slip. Release the grip on the pliers in the manner described in the above WARNING. Remove the second retaining ring in the same manner. The rings are identical and either one may be installed first. 12-Remove the retainer plate. As the plate is removed, notice which surface is facing into the housing, as an aid during installation. 13-Reach inside the cavity and remove the thrust bearing, thrust washer and the reverse gear. Propeller Shaft -Removal 14-Grasp the propeller shaft firmly and withdraw it from the lower unit. "FROZEN" PROPELLER SHAFT On rare occasions, especially if water has been allowed to enter the lower unit, it may not be possible to withdraw the propeller shaft as described in Step 1'-1-. The shaft may be "frozen" in the hydraulic pump due to corrosion. If efforts to remove the propeller shaft after the bearing carrier has been removed fail: Obtain a block of wood 2"x 4" approx. one foot in length. Drill a hole in the center of the flat side, large enough for the propeller shaft to pass through. Place the block over the shaft. Slide some thick large washers over the shaft and thread the propeller nut on to the shaft. With the skeg clamped securely in a vise equipped with soft jaws, attempt to pull the shaft free. If necessary hammer on the wood, rotating the block at intervals to preven t wedging the shaft in any one direction. Pinion Gear -Removal Special tool, OMC No. 316612 is required to turn the driveshaft in order to remove the pinion gear nut. 15-Obtain the special tool and slip it over the end of the driveshaft with the splines of the tool indexed with the splines on the driveshaft. Hold the pinion gear nut with the proper size wrench, and at the same time rotate the driveshaft, with the ELECTRIC SHIFT 8-121 special tool and wrench COUNTERCLOCKWISE until the nut is free. If the special tool is not available, clamp the driveshaft in a vise equipped with soft jaws, in an area below the splines but no t in the water pump impeller area. Now, with the proper size wrench on the pinion gear nut, rota te the complete lower unit COUNTERCLOCKWISE until the nut is free. This procedure will probably require the driveshaft to be loosened in the vise several times and reclarnped in order to affect rotation of the lower unit and wrench. After the nut is free, proceed wi th the next step. The driveshaft will be withdrawn from the pinion gear. Driveshaft -Removal 16-Remove the four bolts from the too · of the lower unit securing the bearing hous ing. CAREFULLY pry the bearing housing upward away from the lower unit, then slide it free of the driveshaft. An alternate method is to again clamp the driveshaft in a vise equipped with soft jaws. Use a softheaded mallet and tap on the top side of the bearing housing. This action will jar the housing loose from the lower unit. Continue tapping with the mallet and the bearing housing, 0-rings, shims, thrust washer, thrust bearing, and the driveshaft will all 8-122 LOWER UNIT breakaway from the lower unit and may be removed as an assembly. 17-Remove the pinion gear from the lower unit cavity. Remove the forward gear from the hydraulic pump. Hydraulic Pump -Removal 18-Obtain two long rods with 1 /4" x 20 threads on both ends. Thread the two rods into the hydraulic pump housing. Attach a slide hammer to the rods and secure it with a nut on the end of each rod. Check to be sure the slide hammer is installed onto the rods EVENLY to allow an even pull on the pump. If the slide hammer is not installed the rods properly, the pump may become Lower Driveshaft Bearing -Removal This bearing cannot be removed without the aid of a special tool. Therefore, DO NOT attempt to remove this bearing unless it is unfit for further service. To check the bearing, first use a flashlight and inspect it for corrosion or other damage. Insert a finger into the bearing, and then check for "rough" spots or binding while rotating it. 19-For 1971 models ONLY: Use a punch, or similar tool and drive the lower driveshaft bearing out of position and into the lower unit cavity. to tigh tly wedged in the lower unit. Operate the slide hammer and pull the hydraulic pump free. If the pump should happen to become lodged in the lower unit, stop operating the slide hammer IM MEDIATELY. Tap the hydraulic pump back into place in the lower unit and start the removal procedure over. ELECTRIC SHIFT 8-123 For 1972 models ONLY: Remove the ALLEN screw from the water pickup slots in the starboard side of the lower unit housing, reference illustration ''E11• This screw secures the bearing in place and MUST be removed ·before an attempt is made to remove the bearing. The bearing must ac tually be "PULLED11 upward to come free. NEVER make an attempt to "drive" it down and out or the lip in the lower unit holding the bearing will be broken off. VERY BAD NEWS. The lower unit housing would have to be replaced. Obtain special tool, OMC No. 385546. Use the special tool and "pull" the bearing from the lower unit, reference illustration npn. Propeller Shaft -Disassembling 20-Notice the spring retainer on the outside surface of the clu tch dog. Use a small screwdriver and work one end of the spring up onto the shoulder of the clutch dog. Continue working the spring out of the groove until it is free. TAKE CARE not to distort the spring. Place one end of the propeller shaft on the bench and push the pin free of the clutch dog. Raise the propeller end of the shaft upward and the piston, retainer, and spring, will come free of the shaft. 21-Notice how the small end of the retainer fits into the spring. Also notice the hole in the retainer. During installation, this hole must align with the hole in the propeller shaft and clutch dog to allow the pin to pass through. Slide the clutch dog free of the propeller shaft. 8-124 LOWER UNIT Hydraulic Pump -Disassembling 22-Remove the screw from the center of the screen on the back side of the pump. Remove the screen. 23-Remove the screws securing the valve housing to the pump, and then lift the housing free of the pump. 24-Lift the two gears out off the pump housing and HOLD them just as they were removed. Check the face of each gear for an indent mark (a dot, dimple, or similar 25-Use a seal remover to remove the two back-to-back seals or clamp the carrier in a vise and use a pry bar to pop each seal out. 26-Use a drift punch to drive the bearings free of the carrier. The bearings are being removed because they are unfit for service, therefore, additional damage is of no consequence. identification). The identifica tion mark will indicate how the gear MUST face in the housing. Make a note of how the mark faces, outward or inward, to ENSURE the gears will be installed properly in the same position from which they were removed. Bearing Carrier -Disassembling The bearings in the carrier need NOT be removed unless they are unfit for further service. Inser t a finger and rotate the bearing. Check for "rough" spots or binding. Inspect the bearing for signs of corrosion or other types of damage. If the bearings must be replaced, proceed with the next step. Solenoid and Shift Assembly It is not recommended to attempt service of this assembly. If troubleshooting has been performed and the determination made the unit or any part is faulty, the ONLY satisfactory solution is to purchase and install a new assembly. CLEANING AND INSPECTING Wash all, except ELECTRICAL, parts in solvent and dry them with compressed air. Discard all 0-rings and seals that have been removed. A new seal kit for this lower unit is available from the local dealer. The kit will contain the necessary seals and 0-rings to restore the lower unit to service. Inspect all splines on shafts and in gears for wear, rounded edges, corrosion, and damage. Carefully check the driveshaft and the propeller shaft to verify they are straight and true without any sign of damage. A complete check must be performed by turning the shaft in a lathe. This is only necessary if there is evidence to suspect the shaft is not true. Check the water pump housing for corrosion on the inside and verify the impeller ELECTRIC SHIFT 8-125 A two-section driveshaft with a weld section that has failed. This area of the driveshaft should be carefully checked anytime the lower unit is disassembled. and base plate are in good condition. Actually, good shop practice dictates to rebuild or replace the water pump each time the lower unit is disassembled. The small cost is rewarded with "peace of mind" and satisfactory service. Inspect the lower unit housing for nicks, dents, corrosion, or other signs of damage. Nicks may be removed with No. 120 and No. 180 emory cloth. Make a special effort to ensure all old gasket material has been removed and mating surfaces are dean and smooth. Inspect the water passages in the lower unit to be sure they are clean. The screen may be removed and cleaned. Check the gears and clutch dog to be sure the ears are not rounded. If doubt exists as to the part performing satisfactorily, it should be replaced. Inspect the bearings for "rough" spots, binding, and signs of corrosion or damage. Damaged hydraulic pump. Water in the lower unit and a broken gear was the cause of this pump being destroyed. ELECTR I C SHIFT 8- 1 27 Damaged reverse gear (left) and forward gear (right). This damage was caused from water entering the lower unit. Test the neutral and reverse solenoids with an ohmmeter. A reading of 5 to 7 ohms is normal and indicates the solenoid is in satisfactory condition. ASSEMBLING READ AND BELIEVE The lower unit should NOT be assembled in a dry condition. Coat all internal parts with OMC HI-VIS lube oil as they are assembled. All seals should be coated with OMC Gasket Seal Compound. When two seals are installed back-to-back, use Triple Guard Grease between the seal surfaces. AUTHORS APOLOGY The accompanying illustrations show a rubber seal on the end of the hydraulic pump and a snap ring installed in front of the pump. During 1971 and 1972, these two items were not used. Therefore, disregard the seal and snap ring, for these two years. Propeller Shaft --Assembling 1-Slide the clutch dog onto the propeller shaft with the face of the dog marked "PROP END" facing toward the propeller end of the shaft, reference illustration "A". Before the splines of the clutch dog engage the splines of the propeller shaft, rotate the dog until the hole for the pin appears to align with the hole through the propeller shaft. Slide the clutch dog onto the splines until the hole in the dog aligns with the hole in the shaft. If the hole is off just a bit, slide the clutch dog back off the splines, rotate it one spline in the required direction, and then slide it into place. Insert the spring into the end of the propeller shaft. Secure the spring in place with the spring retainer. Install the retainer with the small end going into the propeller shaft FIRST. Using an ohmmeter to test the solenoids, as explained in the text. 8-128 LOWER UNIT 2-Depress the spring retainer and insert the pin through the dutch dog, the shaft, spring retainer, and out the other side of the shaft and clutch dog. Center the pin through the clutch dog. 3-Install the spring-type pin retainer around the clutch dog to secure the pin in place. TAKE CARE not to distort the pin retainer during the installation process. Bearing Carrier Bearings & Seals Installation 4-Install the reverse gear bearing into the bearing carrier by pressing against the LETTERED side of the bearing with the proper size socket. Press the forward gear bearing into the bearing carrier in the same manner. Press against the LETTERED side of the bear in g. 5-Coat the outside surfaces of the seals with HI-VIS oil. Install the first seal with the flat side facing OUT. Coat the flat surface of both seals with Triple Guard Grease, and then install the second seal with the flat side going in FIRST. The seals are then back-to-back with the grease between the two surfaces. The outside seal prevents water from entering the lower unit and the inside seal prevents the lubricant in the lower unit from escaping. ELECTRIC SHIFT 8-129 A set of double seals showing the back side (left) and the front side (right). These seals are installed back-to-back (flat side-to-flat side) with Triple Guard Grease between the surf aces. This arrangem ent prevents fluid from passing in either direction. Hydraulic Pump -Assembling 6-Check the note made during disassembling, per Step 23, to determine how the identifying marks (dots, dimples, whatever) on the gears must face --inward or outward. The gears MUST be installed in the same position from which they were removed. 7-Install the rear valve housing with the tang on the outside edge of the housing indexed with the small slot in the pump housing. Secure the valve housing in place with the attaching screws tightened securely. 8-Place the screen in position on the back side of the valve housing, and then secure it in place with the screw. 9Install the forward gear into the pump housing. It may be necessary to work the gears around in the pump to permit the tangs on the forward gear shank to index in the slots in the housing. Set the assembly aside for later installation. Two types of hydraulic pumps. The pump on the left is the most common with the shift rod passing through a hole in two levers on top of the pump. The pump on the right has the shift rod passing directly through a hole in the pump top. 8-1 30 LOWER UNIT Lower Driveshaft Bearing -Installation 10-Obtain tool, OMC No. 385546. Assemble the tool with the washer, guide sleeve, and remover portion of the tool, in the order given. The shoulder of the tool must face DOWN. Place the bearing onto the end of the tool, with the lettered side of the bearing facing the tool. Drive the bearing down until the large washer on the tool makes contact with the surface of the lower unit. The bearing is then seated to the proper depth. 11-If an Allen screw is used to secure the bearing in place, apply Loctite to the threads, amd then install the screw through the lower unit, as shown. Hyraulic Pump --Installation First, These Words Observe the tang on the backside of the pump. This tang MUST face directly up in relation to the lower unit housing to permit installation of the shift rod into the pump. Also notice the pin on the backside of the pump. This pin MUST index into a matching hole in the housing to restrain the pump from rotating. 12-Secure the lower unit housing in the horizontal position with the bearing carrier opening facing up. Remove the forward gear from the pump. Obtain two long 1/4 x 20 rods with threads on both ends. Thread the rods into the pump and then lower the pump into the lower unit housing. To index the pin on the back of the pump housing into the hole in the lower unit is not an easy task. However, exercise patience and rotate the pump ever so slowly. A helpful hint at this point: As the pump is being lowered into the cavity, align the opening and tang on top of the pump in the approximate position your eye indicates the shift rod may be installed. When the pin indexes, it will not be possible to rotate the pump. The pump MUST be properly seated to permit installation of the shift rod and the pinion gear. After the pump is in place, remove the two rods used during installation. 13-Coat the plung..r with oil, and then lower the large end of the plunger into the hydraulic pump. Check to be sure it seats all the way into place. 14-Install the thrust washer and thrust bearing into the pump with the flat side of the bearing facing OUTWARD. Lower the forward gear into the pump. Work the gear slowly until the teeth index with the teeth of the pump gear. This should not be too difficult because the forward gear was installed once, and then removed in the previous step. However, i.t is entirely possible the gears moved when the pump was installed. Therefore, use a flashlight and check the position of the gears. If necessary, use a long shank screwdriver and rotate the gears until they are close to center, then install the forward gear. Driveshaft and Pinion Gear --Installation CRffiCAL WORDS The driveshaft and pinion gear must be assembled prior to installation, and then checked with a special shimming gauge. This shimming must be accomplished properly, the unit disassembled, and then installed into the lower unit. Use of the shimming gauge is the ONLY way to determine the proper amount of shimming required at the upper end of the driveshaft. The following detailed step outlines the procedure. 15-Clamp the driveshaft in a vise equipped with soft jaws and in such a manner that the splines, water pump area, or other critical portions of the shaft cannot ELECTRIC SHIFT 8-131 be damaged. Slide the pmwn gear onto the driveshaft with the bevel of the gear teeth facing toward the lower end of the shaft. Install the pinion gear nut and tighten it to a torque value of 40 to 45 ft-lbs. No parts should be installed on the upper end of the driveshaft at this point. Slide the same amount of shim material removed during disassembling, onto the driveshaft and seat it against the driveshaft shoulder. Obtain special shimming tool, OMC No. 315767. Slip the special tool down over the driveshaft and onto the upper surface of the top shim. Measure the distance between the 8-132 LOWER UNIT top of the pinion gear and the bottom of the tool. The tool should just barely make contact with the pinion gear surface for ZERO clearance. Add or remove shims from the upper end of the driveshaft to obtain the required ZERO clearance. Remove the tool and set the shims aside for installation later. Back off the pinion gear nut and remove the pinion gear. Remove the driveshaft from the vise. 16-Insert the pinion gear into the cavity in the lower unit with the flat side of the bearing facing UPWARD. Hold the pinion gear in place and at the same time lower the driveshaft down into the lower unit. As the driveshaft begins to make contact with the pinion gear , rotate the shaft slightly to permit the splines on the shaft to index with the splines of the pinion gear. After the shaft has indexed with the pinion gear, thread the pinion gear nut onto the end of the shaft. Obtain special tool, OMC No. 316612. Slide the special tool over the upper end of the driveshaft with the splines of the tool indexed with the splines on the shaft. Attach a torque wrench to the special tool. Now, hold the pinion gear nut with the proper size wrench and rotate the driveshaft CLOCKWISE with the special tool until the pinion gear nut is tightened to a torque value of 40 to 45 ft-lbs. Remove the special tool. 17-Slide the thrust bearing, thrust washer, and the shims, set aside after the shim gauge procedure in Step 15, onto the drives haft. 18-Install the two seals back-to-back into the opening on top of the bearing housing. Coat the outside surface of the NEW seals with OMC Lubricant. Press the first seal into the housing with the flat side of the seal facing OUTWARD. After the seal is in place, apply a coating of Triple Guard Grease to the flat side of the installed seal and the flat side of the second seal. Press the second seal into the bearing housing with the flat side of the seal facing INWARD. Insert a NEW 0-ring into the bottom opening of the bearing housing. ELECTRIC SHIFT 8-133 19-Wrap friction tape around the splines of the driveshaft to protect the seals in the bearing housing as the housing is installed. Now, slide the assembled bearing housing down the driveshaft and seat it in the lower unit housing. Secure the housing in place with the four bolts. Tighten the bolts ALTERNATELY and EVENLY. Propeller Shaft -Installation 20-Secure the lower unit in the horizontal position with the bearing carrier opening facing UPWARD. Check the inside diameter of the forward gear to be sure the small thrust washer in the gear is still in place. Lower the propeller shaft assembly down into the lower unit with the inside diameter of the shaft indexing over the shaft of the piston. 21-Apply a light coating of grease to the inside surface of the reverse gear to hold the thrust washer in place. Insert the thrust washer into the reverse gear. Lower the thrust bearing and thrust washer down onto the shank of the reverse gear. Slide the reverse gear down the propeller shaft with the splines of the reverse gear indexing with the splines of the shaft. 22-Insert the retainer plate into the lower unit against the reverse gear. WARNING This next step can be dangerous. Each snap ring is placed under tremendous tension with the Truarc pliers while it is being 8-1 34 LOWER UNIT placed into the groove. Therefore, wear SAFETY GLASSES and exercise care to prevent the snap ring from slipping out of the pliers. If the snap ring should slip out, it would travel with incredible speed and cause personal injury if it struck a person. 23-Install the Truarc snap rings one ata- time following the precautions given in the WARNING and the ADVICE given in the following paragraph. WORDS OF ADVICE The two snap rings index into separate grooves in the lower unit housing. As the first ring is being installed, depth perception may play a trick on yours eyes. It may appear that the first ring is properly indexed all the way around in the proper groove, when in reality, a portion may be in one groove and the remainder in the other groove. Should this happen, and the Truarc pliers be released from the ring, it is extremely difficult to get the pliers back into the ring to correct the condition. If necessary use a flashlight and carefully check to be sure the first ring is properly seated all the way around BEFORE releasing the grip on the pliers. Installation of the second ring is not so difficult because the one groove is filled with the first ring. 24-Obtain two long 1/4" rods with threads on one end. Thread the rods into the retainer plate opposite each other to act as guides for the bearing carrier. 25-Check the bearing carrier to be sure a NEW 0-ring has been installed. Position the carrier over the guide pins with the embossed word UP on the rim of the carrier facing UP in relation to the lower unit housing. Now, lower the bearing carrier down over the guide pins and into place in the lower unit housing. 26-Slide NEW little 0-rings onto each bolt, and apply some OMC Sealer onto the threads. Install the bolts through the carrier and into the retaining plate. After a couple bolts are in place, remove the guide pins and install the remaining bolts. Tighten the bolts EVENLY and ALTERNATELY to the torque value given in the Appendix. ELECTRIC SHIFT 8-135 lever and check ball assembly. Check to be Shift Cable, Solenoids, and Rod -Assembling CRITICAL WORDS The following procedures MUST be performed exactly as given and in the order presented. Do not attempt any shortcuts or anticipate what will be done next. All parts must be installed and adjusted to the letter, for the unit to function properly. Separate the upper (green) solenoid from the lower (blue) solenoid, by pulling them apart. An inner shift rod will be released from the shift rod casing. Check to be sure the cap on the bottom of the shift rod casing is in place. sure the solenoid is fully seated in the housing. The lower plunger should be flush with the top of the solenoid. 28-If the plunger is not flush with the solenoid, remove the solenoid and screw the lower plunger up or down on the shift rod casing, then install the solenoid again and check the plunger. 29-Install the spacer with the lip on the spacer facing UPWARD. .30-Lower the green solenoid into the lower unit housing. Insert the shift rod into the shift rod casing. 31-The upper plunger must be flush with the top surface of the solenoid. If it is not flush with the solenoid, remove the 27-Lower the blue solenoid down into the lower unit housing. Continue lowering the solenoid until the cap on the end of the shift rod casing seats on top of the valve solenoid, loosen the nut, and make an adjustment. Install the solenoid again and check the upper plunger. 8-136 LOWER UNIT 32-Check to be sure the inside plunger indexes into the hole in the hydraulic pump. 33-Install the wavy washer and a NEW gasket into the lower unit housing. Work the shift wires down into the lower unit cavity. Lower the cover into place in the lower unit housing. The wavy washer will give you a false pressure against the cap. Therefore, it takes a bit of patience to be sure the wavy washer indexes into the recess of the cover. Start the bolts securing the cover. Tighten the bolts ALTERNATELY and EVENLY. As the bolts are tightened. This may not be ac..omplished on the first attempt, but keepmg cool and working slowly will be rewarded with success. 34-Obtain an ohmmeter. Ground one lead of the meter, and then check the blue and green wires for continuity. The ohmmeter should indicate 5 to 7 ohms. tightened, make continuous checks to be sure the wavy washer and the green solenoid fit up into the cover as the bolts are ELECTRIC SHIFT 8-137 WATER PUMP INSTALLATION FIRST, THESE WORDS An improved water pump is available as a replacement. If the old water pump housing is unfit for further service, only the new pump housing can be purchased. It is strongly recommended to replace the water pump with the improved model while the lower unit is disassembled. The accompanying illustration shows the original equipment (left) compared with the improved pump (right), reference illustration "A". The new pump must be assembled before it is installed. Therefore, the following steps outline procedures for both pumps. To assemble and install a replacement pump, perform steps 35 thru 43, then jump to Step 46. To install an original equipmen t pump, proceed direectly to Step 44. Assembling an Improved Pump Housing 35-Remove the water pump parts from the con tainer. Inser t the plate into the housing, as shown. The tang on the bottom side of the plate MUST index int0 the short slot in the pump housing. 36-Slide the pump liner into the housing with the two small tabs on the bottom side indexed into the two cutouts in the plate. 37-Coat the inside diameter of the liner with light-weight oil. Work the impeller into the housing with all of the blades bent back to the right, as shown. In this posi tion, 8-138 LOWER UNIT the blades will rotate properly when the pump housing is installed. Remember, the pump and the blades will be rotating CLOCKWISE when the housing is turned over and installed in place on the lower unit. 38-Coat the mating surface of the lower unit with 1000 Sealer. Slide the water pump base plate down the dr iveshaft and into place on the lower unit. Insert the Woodruff key into the key slot in the driveshaft. 39-Lay down a very thin bead of 1000 sealer into the irregular shaped groove in the housing. Insert the seal into the groove, and then coat the seal with the 1000 Sealer. Water Pump Installation 40-Begin to slide the water pump down the driveshaft, and at the same time observe the position of the slot in the impeller. Continue to work the pump down the driveshaft, with the slot in the impeller indexed over the Woodruff key. The pump must be fairly well aligned before the key is covered because the slot in the impeller is not visible as the pump begins to come close to the base plate. 41-Install the short forward bolt through the pump and into the lower unit. DO NOT tighten this bolt at this time. Insert the grommet into the pump housing. Slide the water pump plate down the driveshaft and BEFORE it makes contact with the sealer check to be sure the bolt holes in the plate will align with the holes in the housing. The plate will only fit one way. If the holes will not align, remove the plate, turn it over and again slide the plate down the dr iveshaft and into place on the housing. proper position inside the housing. to rotate the driveshaft and work the water pump housing downward until it is seated on the plate. Coat the threads of the water pump attaching screws with sealer , and then secure the pump in place with the screws. Install the solenoid cable bracket with the same bolt and in the same position from Slide the water pump plate down the driveshaft and BEFORE it makes contact with the sealer check to be sure the bolt holes in the plate will align with the holes in the housing. The plate will only fit one way. If the holes will not align, remove the plate, turn it over and again slide the plate down the dr iveshaft and into place on the housing. proper position inside the housing. to rotate the driveshaft and work the water pump housing downward until it is seated on the plate. Coat the threads of the water pump attaching screws with sealer , and then secure the pump in place with the screws. Install the solenoid cable bracket with the same bolt and in the same position from ELECTRIC SHIFT 8-139 42-Install the grommet retainer and water tube guide onto the pump housing. Install the remaining pump attaching bolts. Tigh ten the bolts ALTERNATELY and EVENLY, and at the same time rotate the driveshaft CLOCKWISE. If the driveshaft is not rotated while the attaching bolts are being tightened, it is possible to pinch one of the impeller blades underneath the housing. 43-Slide the large grommet down the driveshaft and seat it over the pump collar. This grommet does not require sealer. Its function is to prevent exhaust gases from entering the water pump. Proceed directly to Lower Unit Installation, Step 47. Water Pump Installation Original Equipment Perform the following two steps to install an original water pump. 44-Coat the water pump plate mating surface on the lower unit with 1000 Sealer. This checking will prevent accidently getting the sealer on both sides of the plate. If by chance sealer does get on the top surface it MUST be removed before the water pump impeller is installed. Slide the water pump impeller down the driveshaft. Just before the impeller covers the cutout for the Woodruff key, install the key, and then work the impeller on down, with the slot in the impeller indexed over the Woodruff key. Continue working the impeller down until it is firmly in place on the surface of the pump plate. IJ.5-Check to be sure NEW seals and 0rings have been installed in the water pump. Lubricate the inside surface of the water pump with light-weight oil. Lower the water pump housing down the driveshaft and over the impeller. ALWAYS rotate the driveshaft slowly CLOCKWISE as the housing is lowered over the impeller to allow the impeller blades to assume their natural and Continue 8-140 LOWER UNIT which it was removed. On some units the solenoid cable fits into a recess of the water pump and is held in place in that manner. Tighten the screws ALTERNATELY and EVENLY. LOWER UNIT INSTALLATION 46-Check to be sure the water tubes ' are clean, smooth, and free of any corrosion. Coat the water pickup tubes and grommets with lubricant as an aid to installation. Check to be sure the spark plug wires are disconnected from the spark plugs. Bring the lower unit housing together with the exhaust housing, and at the same time, guide the water tube into the rubber grommet of the water pump. Connect the ends of the wire left in the exhaust housing during removal to the blue and green wires from the lower unit. Tape the connections, and then oil the shift cable as an aid to slipping the cable through the exhaust housing. Continue to bring the two units together and at the same time: pull the wires through the exhaust housing; guide the water pickup tubes into the rubber grommet of the water pump; and, rotate the flywheel slowly to permit the splines of the driveshaft to index with the splines of the crankshaft. This may sound like it is neces so it is. Therefore, make an earnest attempt to secure the services of an assistant for this task. 47-After the surfaces of the lower unit and exhaust housing are close, dip the attaching bolts in Ol\!',C Sealer and then start them in place. Two bolts are used on each side of the two housings. 48-Install the retaining bolt in the recess of the trim tab and another bolt in the cavitation plate. Tighten the bolts ALTERNATELY and EVENLY to the torque value given in the Appendix. sary to do four things at the same time, and 49-Install the trim tab with the mark made on the tab during disassembling aligned with the mark made on the lower unit housing. 50-Disconnect and remove the "pull" wire used to feed the electrical wires up through the exhaust housing. 51-Obtain an ohmmeter. Ground the meter and again check the green and blue wires for continuity. The meter should indicate 5 to 7 ohms. Connect the green wire to the green wire and the blue wire to the blue wire. After the connections have been made, slide the sleeve down over the connections. A bit of oil on the wires will allow the sleeves to slide more easily. Filling the Lower Unit Fill the lower unit with lubricant according to the procedures in Section 8-3. Propeller Installation Install the propeller, see Section 8-2. FUNCTIONAL CHECK Perform a functional check of the completed work by mounting the engine in a test tank, in a body of water, or with a flush attachment connected to the lower unit. If the flush attachment is used, NEVER operate the engine above an idle speed, because the no-load condition on the propeller would allow the engine to RUNAWAY resulting in serious damage or destruction of the engine. ELECTRIC SHIFT 8-141 CAUTION: Water must circulate through the lower unit to the engine any time the engine is run to prevent damage to the water pump in the lower unit. Just five seconds without water will damage the water pump. Start the engine and observe the tattletale flow of water from idle relief in the exhaust housing. The water pump installation work is verified. If a "Flushette" is connected to the lower unit, VERY LITTLE water will be visible from the idle relief port. Shift the engine into the three gears and check for smoothness of operation and satisfactory performance. Remember, when the unit is in forward gear, it is at rest with no current flow to either solenoid. Helm-type shift box and steering wheel. 8-142 LOWER UNIT 8-12 MECHANICAL SHIFT HYDRAULIC ASSIST SHIFT DISCONNECT UNDER LOWER CARBURETOR 50 HP 1973-74 DESCRIPTION The lower unit covered in this section is a three shift position, hydraulic activated, propeller exhaust unit. A hydraulic pump mounted in the forward portion of the lower unit provides the force required to shift the unit. A shift rod extends down through the exhaust housing and lower unit to an assist cylinder. A push rod connects the assist cylinder and the hydraulic pump. The pump valve directs the hydraulic force to place the clutch dog in the desired position for neutral, forward, or reverse gear position. When the shift rod is in the upward position, the system is at rest and the lower unit is in forward gear. In simple terms, something must be done to move the unit into neutral or reverse gear position. If no action is taken (shift mechanism at rest) the unit is i.n the forward gear position. As the shift control lever is moved at the control box, the shift rod moves in the assist cylinder; the valve in the cylinder is activated; the push rod is moved, allowing Cut-a-way view of a 50 hp, 1973-7 4 lower unit with major parts exposed. This type of illustration will be most helpful during work on the lower unit. oil from the pump to pass up through the hollow push rod into the assist cylinder; the shift mechanism is thereby "assisted" for easier and smoother shifting. The lower unit houses the driveshaft and pinion gear, the forward and reverse driven gears, the propeller shaft, clutch dog, hy draulic pump, assist cylinder and the neces sary shims, bearings, and associated parts to make it all work properly. The water pump is considered a part of the lower unit. TROUBLESHOOTING Preliminary Checks At rest, and without the engine running, the lower unit is in forward gear. Mount the engine in a test tank, in a body of water, or with a flush attachment connected to the lower unit. If the flush attachment is used, NEVER operate the engine above an idle speed, because the no-load condition on the propeller would allow the engine to RUNAWAY resul ting in serious damage or destruction of the engine. CAUTION: Water must circulate through the lower unit to the engine any time the engine is run to prevent damage to the water pump in the lower unit. Just five seconds without water will damage the water pump. Attempt to shift the unit into NEUTRAL and REVERSE. It is possible the propeller may turn very slowly while the unit is in neutral, due to "drag" through the various gears and bearings. If difficult shifting is encountered, the problem is in the shift linkage or in the lower unit. The second area to check is the quantity and quality of the lubricant in the lower unit. If the lubricant level is low, contaminated with water, or is broken down because of overuse, the shift mechanism may be affected. Water in the lower unit is VERY BAD NEWS for a number of reasons, particularly when the lower unit contains hydraulic components. Hydraulic units will not function with water in the system. Remember, when the engine is not running, the unit should be in FORWARD gear. BEFORE making any tests, remove the propeller, see Section 8-2. Check the propeller carefully to determine if the hub has been slipping and giving a false indication the unit is not in gear, reference illustration "A". If there is any doubt, the propeller should be taken to a shop properly equipped for testing, before the time and expense of disassembling the lower unit is undertaken. The expense of the propeller testing and possible rebuild is justified. The following troubleshooting procedures are presented on the assumption the lower unit lubricant, and the propeller have been checked and found to be satisfactory. MECH SHIFT HYD ASSIST 8-143 Lower Unit Locked Determine if the problem 1s m the powerhead or in the lower unit. Attempt to rotate the flywheel. If the flywheel can be moved even slightly in either direction, the problem is most likely in the lower unit. If it is not possible to rotate the flywheel, the problem is a "frozen" powerhead. To absolutely verify the powerhead is "frozen", separate the lower unit from the exhaust housing and then again attempt to rotate the flywheel. If the attempt is successful, the problem is definitely in the lower unit. If the attempt to rotate the flywheel, with the lower unit removed, still fails, a "frozen" powerhead is verified, reference illustration ''Bn. Unit Fails to Shift Neutral, Forward, or Reverse With the outboard moun ted on a boat, in a test tank, or with a flush attachment connected, disconnect the shift lever at the engine. Attempt to manually shift the unit into NEUTRAL, REVERSE, FORWARD. At the same time move the shift handle at the shift box and determine that the linkage and shift lever are properly aligned for the shift positions. If the alignment is not correct, adjust the shift cable at the trunnion. It is 8-144 LOWER UNIT also possible the inner wire may have slipped in the connector at the shift box. This condition would result in a lack of inner cable to make a complete "throw" on the shift handle. Check to be sure the shift handle is ·moved to the full shift position and the linkage to the lower unit is moved to the full shift position. If an adjustment is required at the shift box, see Chapter 7. If it is not possible to shift the unit into gear by manually operating the shift rod while the engine is running, the lower unit requires service as described in this section. LOWER UNIT SERVICE Propeller Removal If the propeller was not removed, as directed for the troubleshooting, remove it now, according to the procedures outlined in Section 8-2. Draining the Lower Unit Drain the lower unit of lubricant, see Section 8-3. GOOD WORDS If water is discovered in the lower unit and the propeller shaft seal is damaged and requires replacement, the lower unit does NOT have to be removed in order to accomplish the work. The bearing carrier can be removed and the seal replaced without disassembling the lower unit. HOWEVER such a procedure is not considered good shop practice, but merely a quick-fix. If water has entered the lower unit, the unit should be disassembled and a detailed check made to determine if any other seals, bearings, bearing races, 0rings or other parts have been rendered unfit for further service by the water. Shift and throttle linkaqe on the 50 hp, 1973-74 engines. LOWER UNIT REMOVAL 1-Disconnect and ground the spark plug wires. Remove the bolt or bolts from the shift disconnect coupler under the lower carburetor. 2-Scribe a mark on the trim tab and a matching mark on the lower unit to ensure the trim tab will be installed in the same position from which it is removed. Use an Allen wrench and remove the trim tab. 3-Use a 1/2" socket with a short extension and remove the bolt from inside the trim tab cavity. Remove the 5/8" countersunk bolt located just ahead of the trim tab position. IB-Remove the four 9/16" bolts, two on each side, securing the lower unit to the exhaust housing. 5-Work the lower unit free of the exhaust housing. If the unit is still mounted on a boat, tilt the engine forward to gain clearance between the lower unit and the deck (floor, ground, whatever). EXERCISE CARE to withdraw the lower unit straight away from the exhaust housing to prevent bending the driveshaft. WATER PUMP REMOVAL 6-Position the lower unit in the vertical position on the edge of the work bench resting on the cavitation plate. Secure the MECH SHIFT HYD ASSIST 8-145 lower unit in this position with a C-clamp. The lower unit will then be held firmly in a favorable position during the service work. An alternate method is to cut a groove in a short piece of 2" x 6" wood to accommodate the lower unit with the cavitation plate resting on top of the wood. Clamp the wood in a vise and service work may then be performed with the lower unit erect (in its 8-146 LOWER UNIT normal position), or inverted (upside down). In both positions, the cavitation plate is the supporting surface. 7-Remove the 0-ring from the top of the driveshaft. Remove the bolts securing the water pump to the lower unit housing. Pull the water pump housing up and free of the driveshaft. Slide the water pump impeller up and free of the driveshaft. 8-Pop the impeller Woodruff key out of the driveshaft keyway. Slide the water pump base plate up and off of the driveshaft. GOOD WORDS If the only work to be performed is service of the water pump, proceed directly to Page 8-167, Water Pump Installation. Assist Cylinder -Removal 9-Remove the four screws at the front edge of the lower unit. Lift and slide the cover up and free of the shift rod. Bearing Carrier -Removal 10-Remove the four 5/16" bolts from inside the bearing carrier. Notice how each bolt has an 0-ring seal. These 0-rings should be replaced each time the bolts are removed. In most cases, the word UP is embossed into the metal of the bearing carrier rim. This word must face UP in relation to the lower unit during installation. pliers, it will travel with incredible speed either one may be installed first. Remove the retainer olate. 13-As the plate is removed, notice which surface is facing into the housing, as an aid during installation. 11-Remove the bearing carrier using one of the methods described in the following paragraphs, under Special Words. SPECIAL WORDS Several models of bearing carriers are used on the lower uni ts covered in this sec tion. The bearing carriers are a very tight fit into the lower unit opening. Therefore, it is not uncommon to apply heat to the outside surface of the lower unit with a torch, at the same time the puller is being worked to remove the carrier. TAKE CARE not to overheat the lower unit. One model carrier has two threaded holes on the end of the carrier. These threads permit the installation of two long bolts. These bolts will then allow the use of a flywheel puller to remove the bearing carrier, illustration 11. Another model does not have the threaded screw holes. To remove this type bearing carrier, a special puller with arms must be used. The arms are hooked onto the carrier web area, and then the carrier removed, reference illustration "C". WARNING The next step involves a dangerous procedure and should be execu ted with care while wearing SAFETY GLASSES. The retaining rings are under tremendous tension in the groove and while they are being removed. If a ring should slip off the Truarc MECH SHIFT HYD ASSIST 8-147 causing personal injury if it should strike a person. Therefore, continue to hold the ring and pliers firm after the ring is out of the groove and clear of the lower unit. Place the ring on the floor and hold it securely with one foot before releasing the grip on the pliers. An alternate method is to hold the ring inside a trash barrel, or other suitable container, before releasing the pliers. 12-Obtain a pair of Truarc pliers. Insert the tips of the pliers into the holes of the first retaining ring. Now, CAREFULLY remove the retaining ring from the groove and gear case without allowing the pliers to slip. Release the grip on the pliers in the manner described in the above WARNING. Remove the second retaining ring in the same manner. The rings are identical and 8-148 LOWER UNIT Propeller Shaft -Removal 14-Grasp the propeller shaft firmly with one hand and at the same time grasp the shift rod with your other hand. Now, pull the propeller shaft out and the shift rod upward at the same time. Remove both units from the lower unit. As the propeller shaft is withdrawn, the reverse gear, thrust bearing, washer, and retainer plate will all come out together with the propeller shaft. "FROZEN" PROPELLER SHAFT On rare occasions, especially if water has been allowed to enter the lower unit, it may not be possible to withdraw the propeller shaft as described in Step 14. The shaft may be "frozen" in the hydraulic pump due to corrosion. If efforts to remove the propeller shaft after the bearing carrier has been removed fail: Obtain a block of wood 2"x 4" approx. one foot in length. Drill a hole in the center of the flat side, large enough for the propeller shaft to pass through. Place the block over the shaft. Slide some thick large washers over the shaft and thread the propeller nut on to the shaft. With the skeg clamped securely in a vise equipped with soft jaws, attempt to pull the shaft free. If necessary hammer on the wood, rotating the block at intervals to prevent wedging the shaft in any one direction. The second and less desirable method is as follows: Clamp the propeller shaft horizontally in a vise equipped with soft jaws. Two blocks of wood may be substituted for the soft jaws, bu t NEVER clamp the shaft in the vise without protection, to prevent damage to the threads or splines. Use a soft head mallet and strike the lower unit with quick sharp blows midway between the anticavitation plate and the propeller shaft. This action will drive the lower unit from the propeller shaft. TAKE CARE to hold the lower unit to keep it in line with the propeller shaft and prevent wedging the shaft in any one direction. Holding the lower unit will also prevent the housing from falling to the floor when the housing comes free of the shaft. Pinion Gear -Removal 15-Obtain the special tool and slip it over the end of the driveshaft with the splines of the tool indexed with the splines on the driveshaft. Hold the pinion gear nut with the proper size wrench, and at the same time rotate the driveshaft, with the special tool and wrench COUNTERCLOCKWISE until the nut is free. If the special tool is not available, clamp the driveshaft in a vise equipped with soft jaws, in an area below the splines but not in the water pump MECH SHIFT HYD ASSIST 8-149 1mpeller area. Now, with the proper size wrench on the pinion gear nut, rotate the complete lower unit COUNTERCLOCKWISE until the nut is free. This procedure will require the lower unit to be rotated, then the wrench released, the lower unit turned back, the wrench again attached to the nut, and the unit rotated again. Continue with this little maneuver until the nut is free. After the nut is free, proceed with the next step. The driveshaft will be withdrawn from the pinion gear. Driveshaft -Removal 16-Remove the four bolts from the top of the lower unit securing the bearing housing. CAREFULLY pry the bearing housing upward away from the lower unit, then slide it free of the driveshaft. An alternate method is to again damp the driveshaft in a vise equipped with soft jaws. Use a softheaded mallet and tap on the top side of the bearing housing. This action will jar the housing loose from the lower unit. Continue tapping with the mallet and the bearing housing, 0-rings, shims, thrust washer, thrust bearing, and the driveshaft will all breakaway from the lower unit and may be removed as an assembly. 17-Remove the pinion gear from the lower unit cavity. Remove the forward gear, thrust washer, and thrust bearing, from the hydraulic pump. Hydraulic Pump -Removal 18-Obtain two long rods with 1/4" x 20 threads on both ends. Thread the two rods into the hydraulic pump housing. Attach a slide hammer to the rods and secure it with a nut on the end of each rod. Check to be sure the slide hammer is installed onto the rods EVENLY to allow an even pull on the pump. If the slide hammer is not installed 8-150 LOWER UNIT to the rods properly, the pump may become tightly wedged in the lower unit. Operate the slide hammer and pull the hydraulic pump free. If the pump should happen to become lodged in the lower unit, stop operating the 'slide hammer IMMEDIATELY. Tap the hydraulic pump back into place in the lower unit and start the removal procedure over. Lower Driveshaft Bearing --Removal This bearing cannot be removed without the aid of a special tool. Therefore, DO NOT attempt to remove this bearing unless it is unfit for further service. To check the bearing, first use a flashlight and inspect it for corrosion or other damage. Insert a finger into the bearing, and then check for "rough" spots or binding while rotating it. 19-Remove the Allen screw, if used, from the water pickup slots in the starboard side of the lower unit housing. This screw secures the bearing in place and MUST be removed before an attempt is made to remove the bearing. The bearing must be actually "PULLED'"' upward to come free. NEVER make an attempt to "drive" it down and out. 20-Obtain special tool, OMC No. 385546. Use the special tool and "pull" the bearing from the lower unit. Propeller Shaft -Disassembling SPECIAL WORDS On the 1973 model, the plunger and shift rod bearing are removable. The plunger has a snap ring on the end to secure it in the end of the propeller shaft, exploded reference illustration "F". On the 1974 model, a spring is installed into the end of the propeller shaft. Three detent balls are used on the shift rod and plunger assembling --one ball between the plunger and the spring, and the other two ride partially indexed into holes on opposite sides of the plunger. The accompanying exploded reference illustration "G111, will help clarify the relationship of these parts. 21-Notice the spring retainer on the outside surface of the dutch dog. Use a small screwdriver and work one end of the spring up onto the shoulder of the clutch dog. Continue working the spring out of the groove until it is free. TAKE CARE not to distort the spring. 22-Place one end of the propeller shaft on the bench and push the pin free of the clutch dog. Raise the propeller end of the shaft upward and the piston, plun..er, detent balls, and spring, vlill come free of the shaft, 1974 models only, reference illustration "E". 23-Slide the dutch dog free of the propeller shaft. MECH SHIFT HYD ASSIST 8-151 PROPELLER SHAFT " CLUTCH FORWARD GEAR THRUST SNAP RING BEARIN..SHIFT HRUST OIL PUMP ot AND BEARING a YJ J, RING ; Q . SPRING .,., ® GUIDE BALL SHIFT VALVE 8-152 LOWER UNIT Hydraulic Pump -Disassembling 24-Remove the screw from the center of the screen on the back side of the pump. Remove the screen. 25-Remove the screws securing the valve housing to the pump, and then lift the housing free of the pump. 26-Lift the two gears out off the pump housing and HOLD them just as they were removed. Check the face of each gear for an indent mark (a dot, dimple, or similar identification). The identification mark will indicate how the gear MUST face in the housing. Make a note of how the mark faces, outward or inward, to ENSURE the gears will be installed properly in the same position from which they were removed. Bearing Carrier -Disassembling The bearings in the carrier need NOT be removed unless they are unfit for further service. Insert a finger and rotate the bearing. Check for "rough" spots or binding. Inspect the bearing for signs of corrosion or other types of damage. If the bearings must be replaced, proceed with the next step. 27-Use a seal remover to remove the two back-to-back seals or clamp the carrier in a vise and use a pry bar to pop each seal out. 28-Use a drift punch to drive the bearings free of the carrier. The hearings are being removed because they are unfit for service, therefore, additional damage is of no consequence. MECH SHIFT HYD ASSIST 8-153 Assist Cylinder --Disassembling 29-Back the shift rod out of the assist cylinder by rotating it COUNTERCLOCkWISE until it is free. The threads of the shift rod provide the adjustment, which will be made·at the time of installation. Therefore, it is not necessary to count the number of turns at the time of removal. Two special tools are required to disassemble the assist cylinder further. The assist cylinder can be purchased as a complete assembly. Therefore, it may be less expensive to purchase a new unit rather than buying the special tools and attempting an overhaul. 30-The two special tools required, are both OMC No. 386112. One is used on top of the cylinder and the other on the bottom. Obtain the two tools. Notice the hex head on both ends of the tool. Secure one end in a vise. Slide the lower push rod of the assist cylinder through the special tool and seat it onto the two prongs of the tool. Position the other tool onto the top of the cylinder and back off the cylinder cap. 31-Remove the valve and 0-ring from the cylinder cap. Remove the two 0-rings from the lower end of the cylinder. 32-Remove the retaining pin from the piston and the lower push rod will come free. 8-154 LOWER UNIT "0" RING (SH'b..q.M..HEJFT) ..HORTONLY)SEAL CLAMP SHAFT J ONLY) u-CYLINDER .."O" RING VALVE PUSH ROD OIL RETAINER . Exp o it with maJor parts z l ded vzew o fa 50 hp 197 3 lower un · -·dentified. MECH SHIF T HYD ASSIST 8-155 "0" RIN G GRC/...MET I .! \O 11 ""' ''=' '--" OIL R::TAINER E:xp o ded view of a . l 50 hp --197 4 lower umt with major parts z·dentified. 8-156 LOWER UNIT CLEANING AND INSPECTING Wash all parts in solvent and dry them with compressed air. Discard all 0-rings and seals that have been removed. A new seal kit for this lower unit is available from the local dealer. The kit will contain the necessary seals and 0-rings to restore the lower unit to service. Inspect all splines on shafts and in gears for wear, rounded edges, corrosion, and damage. Carefully check the driveshaft and the propeller shaft to verify they are straight and true without any sign of damage. A complete check must be performed by turning the shaft in a lathe. This is only necessary if there is evidence to suspect the shaft is not true. Check the water purr:p housing for corrosion on the inside and verify the impeller and base plate are in good condition. Actually, good shop practice dictates to rebuild or replace the water pump each time the lower unit is disassembled. The small cost is rewarded with "peace of mind" and satisfactory service. Inspect the lower unit housing for nicks, dents, corrosion, or other signs of damage. Nicks may be removed with No. 120 and No. 180 emery cloth. Make a special effort to ensure all old gasket material has been removed and mating surfaces are dean and smooth. Inspect the water passages in the lower unit to be sure they are clean. The screen may be removed and cleaned. Damaged hydraulic p1mp. Water in the lower unit and a broken gear was the cause of this pump being destroyed. A two-section driveshaft with a weld section that has failed. This area of the driveshaft should be carefully checked anytime the lower unit is disassembled. Check the gears and clutch dog to be sure the ears are not rounded. If doubt exists as to the part performing satisfactorily, it should be replaced. Inspect the bearings for "rough" spots, binding, and signs of corrosion or damage. ASSEMBLING READ AND BELIEVE The lower unit should NOT be assembled in a dry condition. Coat all internal parts with OMC HI-VIS lube oil as they are assembled. All seals should be coated with OMC Gasket Seal Compound. V:'hen two seals are installed back-to-back, use Triple Guard Grease between the seal surfaces. Propeller Shaft -Assembling First, These Words Assembling the propeller shaft for the 1973 model lower unit is somewhat different from the 1974 model. Therefore, two sets of steps are presented --one for each model. For the 1973 model, following Steps 1, 2, and 3, then jump to Step 7. For the 1974 model, begin by skipping to Step 3, and carry on through. For 1973 Model 1-Install the shift rod and bearing assembly into the end of the propeller shaft. Reference exploded illustration "A" on page 8-157 will be helpful during the assembling work. Slide the clutch dog onto the propeller shaft with the face of the dog marked "PROP END" facing toward the propeller end of the shaft. Before the splines of the clutch dog engage the splines of the propeller shaft, rotate the dog until the hole for the pin appears to align with the hole through the propeller shaft. Slide the clutch dog onto the splines until the hole in the dog aligns with the hole in the shaft. If the hole is off just a bit, slide the clutch dog back off the splines, rotate it one spline in the required direction, and then slide it into MECH SHIFT HYD ASSIST 8-157 place. Insert the pin through the clutch dog, the shaft, and out the other side of the shaft and clutch dog. Center the pin through the dutch dog. 2-Install the spring-type pin retainer around the dutch dog to secure the pin in place. TAKE CARE not to distort the pin retainer during the installation process. BREAK All SHARP PROPELLER CLUTCH · p)J..;D I V ::RWARD GEAR 0 .. SPRING PLUNGER SHIFT ROD AND BEARING THRUSt OIL PUMP E.. .. o ·-. ( $j "'. ../0 PLUG . . ''1111!i SPRING GUIDE BALL SHIFT VALVE 8-158 LOWER UNIT shift rod. Now, hold the balls in the shaft, and at the same time carefully align the holes in the shift rod and the dutch dog with the slot in the propeller shaft. Next, insert the shift rod into the propeller shaft until the detent balls slip into the grooves in the propeller shaft. 5-Cover the propeller shaft with a light coating of oil. Slide the clutch dog onto the shaft \Vith the three-lug end facing the propeller end of the shaft. Align the holes in the clutch dog with the slot in the propeller shaft. The words PROP END are stamped on the side intended to face the propeller. 6-With the holes in the clutch dog still aligned with the holes in the shift rod, start the wedge end of the special tool made before Step 1, into the hole with the flat side facing the end of the detent spring. Continue pushing the tool into the hole until the end of the tool barely comes out the opposite side. Now, press the clutch dog retaining pin in through the clutch dog. As the retaining pin is inserted, the tool will be forced out. 7-Secure the pin in place with the retaining spring. TAKE CARE to be sure none of the spring coils overlap or the spring is not distorted in any way. Only through careful attention to installation of the retaining pin and spring can proper operation of the shift mechanism be expected. Set the completed assembly to one side until ready for installation into the lower unit. PROPELLER SHIFT ROD AND PLUNGER ASSEMBLY 1\iJ l@ );. . . . OIL PUMF WASHER DETENT BALLS (3) RETAINING RING PLUG SPRING GUIDE BALL SHIFT VALVE f'. .. . MECH SHIFT HYD ASSIST 8-159 Bearing Carrier Bearings & Seals Installation 8-Install the reverse gear bearing into the bearing carrier by pressing against the LETTERED side of the bearing with the proper size socket. Press the forward gear bearing into the bearing carrier in the same manner. Press against the LETTERED side of the bear in g. 9-Coat the outside surfaces of the seals with HI-VIS oil. Install the first seal with the flat side facing OUT. Coat the flat surface of both seals with Triple Guard Grease, and then install the second seal with the flat side going in FIRST. The seals are then back-to-back with the grease between the two surfaces. The outside seal prevents water from entering the lower unit and the inside seal prevents the lubricant in the lower unit from escaping. Hydraulic Pump -Assembling 10-Check the note made during disassembling, per Step 26, to determine how the identifying marks (dots, dimples, whatever) on the gears must face -inward or outward. The gears MUST be installed in the same position from which they were removed. 11-After the gears have been installed into the pump, use a straightedge and check to be sure the gears are level in the pump. If the gears cannot be made level, either the gears or the pump must be replaced. 8-160 LOWER UNIT 12-Install the rear valve housing with the tang on the outside edge of the housing indexed with the small slot in the pump housing. Secure the valve housing in place with the attaching screws tightened securely. 13-Place the screen in position on the back side of the valve housing, and then secure it in place with the screw. 14-Install the forward gear into the pump housing. It may be necessary to work the gears around in the pump to permit the tangs on the forward gear shank to index in the slots in the housing. Set the assembly aside for later installation. Lower Driveshaft Bearing Installation - 15-Obtain tool, OMC No. 385546. Assemble the tool with the washer, guide sleeve, and remover portion of the tool, in the order given. The shoulder of the tool must face DOWN. Place the bearing onto the end of the tool, with the lettered side of the bearing facing the tool. Drive the bearing down until the large washer on the tool makes contact with the surface of the lower unit. The bearing is then seated to the proper depth. 16-After the bearing has been installed, install the Allen screw through the water pickup vent ramps to secure the bearing in place. Use Loctite on the screw threads before installation. Hyraulic Pump -Installation First, These Words Observe the hole on the topside of the pump. This tang MUST face directly up in relation to the lower unit housing to permit installation of the shift rod into the pump. Also notice the pin on the backside of the pump. This pin MUST index into a matching hole in the housing to restrain the pump from rotating. 17-Secure the lower unit housing in the horizontal position with the bearing carrier opening facing up. Remove the forward gear from the pump. Obtain two long 1/4 x 20 rods with threads on both ends. Thread the rods into the pump and then lower the pump into the lower unit housing. To index the pin on the back of the pump housing into the hole in the lower unit is not an easy task. However, exercise patience and rotate the pump ever so slowly. A helpful hint at this point: As the pump is being lowered into the cavity, align the opening and tang on top of the pump in the approximate position your eye indicates the shift rod may be installed. When the pin indexes, it will not be possible to rotate the pump. The pump MUST be properly seated to permit installation of the shift rod and the pinion gear. After the pump is in place, remove the two rods used during installation. 18-Install the thrust washer and thrust bearing into the pump with the flat side of the bearing facing OUTWARD. Lower the forward gear into the pump. \'ilork the gear slowly until the teeth index with the teeth of the pump gear. This should not be too difficult because the forward gear was installed once, and then removed in the previous step. However, it is entirely possible MECH SHIFT HYD ASSIST 8-161 the gears moved when the pump was installed. Therefore, use a flashlight and check the position of the gears. If necessary, use a long shank screwdriver and rotate the gears until they are close to center, then install the forward gear. Driveshaft and Pinion Gear -Installation CRITICAL WORDS The driveshaft and pmwn gear must be assembled prior to installation, and then checked with a special shimming gauge. This shimming must be accomplished properly, the unit disassembled, and then installed into the lower unit. Use of the shimming gauge is the ONLY way to determine the proper amount of shimming required at the upper end of the driveshaft. The following detailed step outlines the procedure. 19-Clamp the driveshaft in a vise equipped with soft jaws and in such a manner that the splines, water pump area, or other critical portions of the shaft cannot be damaged. Slide the pinion gear onto the driveshaft with the bevel of the gear teeth facing toward the lower end of the shaft. Install the pinion gear nut and tighten it to a torque value of 40 to 45 ft-lbs. No parts should be installed on the upper end of the driveshaft at this point. Slide the shims removed during disassembly onto the driveshaft and seat them against the driveshaft shoulder. Obtain special shimming tool, OMC No. 315767. Slip the special tool down over the driveshaft and onto the upper surface of the top shim. Measure the distance between the top of the pinion gear and the bottom of the tool. The tool should just barely make contact with the pinion gear surface for ZERO clearance. Add or remove shims from the upper end of the driveshaft 8-162 LOWER UNIT to obtain the required ZERO clearance. Remove the tool and set the shims aside for installation later. Back off the pinion gear nut and remove the pinion gear. Remove the driveshaft from the vise. 20-I11sert the pinion gear into the cavity in the lower unit with the flat side of the bearing facing UPWARD. Hold the pinion gear in place and at the same time lower the driveshaft down into the lower unit. As the driveshaft begins to make contact with the pinion gear, rotate the shaft slightly to permit the splines on the shaft to index with the splines of the pinion gear. After the shaft has indexed with the pinion gear, thread the pinion gear nut onto the end of the shaft. Obtain special tool, 0!\..C No. 316612. Slide the special tool over the upper end of the drivesha.ft with the splines of the tool indexed \Vith the splines on the shaft. Attach a torque wrench to the special tool. Now , hold the pinion gear nut with the proper size wrench and rotate the driveshaft CLOCKWISE with the special tool unt.il the pinion gear nut is tightened to a torque value of 40 to 45 ft-lbs. Remove the special tool. 21-Slide the thrust bearing, thrust washer, and the shims, set aside after the shim gauge procedure in Step 19, onto the driveshaft. 22-Install the two seals back-to-back into the opening on top of the bearing housing. Coat the outside surface of the NEW seals with 0!\I:C Lubricant. Press the first seal into the housing with the flat side of the seal facing OUTWARD. After the seal is in place, apply a coating of Triple MECH SHIFT HYD ASSIST 8-163 A set of double seals showing the back side (left) and the front side (right). These seals are installed back-to-back (flat side-to-flat side) with Triple Guard Grease between the surf aces. This arrangement prevents fluid from passing in either direction. Guard Grease to the flat side of the install ed seal and the flat side of the second seal. Press the second seal into the bearing hous ing with the flat side of the seal facing INWARD. Insert a NEW 0-ring into the bottom opening of the bearing housing. 23-Wrap friction tape around the splines of the driveshaft to protect the seals in the bearing housing as the housing is installed. Now, slide the assembled bearing housing down the driveshaft and seat it in the lower unit housing. Secure the housing in place with the four bolts. Tighten the bolts ALTERNATELY and EVENLY. Propeller Shaft --Installation First, Some Good Words Installation of the propeller shaft, assist valve, and plunger is not a simple task. However, with patience, attention to detail, and an understanding of the installation sequence, the work can proceed smoothly without serious problems or the need to disassemble and repeat certain steps. The best word of advice is to read through the following procedure at least twice, or until the various parts and their relationship to each other including the installation sequence is thoroughly familiar. Before these BEARING HOUS ING @ units are installed in the lower unit, some assembling on the bench can be performed. Assemble the propeller shaft and shifter as outlined at the beginning of this section, Steps 1 and 2 for the 1973 model; Steps 3 thru 6 for the 1974 model. Observe how the boss on the plunger slides into the cut-away in the shift rod, reference illustration "C". This arrangement MUST be accomplished when these units are installed in the lower unit. Also observe that the shift rocl on the end of the propeller shaft is heavy on the back side causing the rod to rotate. Therefore, when the propeller shaft is held horizontal, the heavy side will turn the shift rod downward. 24-Lay the lower unit on a flat surface with the port side facing up. Adjust the unit on the bench to offer a clear view into the assist cylinder bore and also into the propeller shaft opening. Now, hold the propeller shaft with the heavy side of the shift rod down and insert it through the oil pump and forward gear assembly. 25-Push the shaft in as far as possible. Use a flashlight to illuminate the interior of the shift assist cylinder bore. Observe the cut-a-way in the shifter rod. If you cannot see the cut-a-way, move the propeller shaft inward or outward until it is visible. With the propeller shaft in this position, CARE 8-164 LOWER UNIT FULLY insert the push rod and assist cylinder assembly into the gearcase with the boss on the cylinder facing down. Continue to slowly move the assembly into the gearcase until it makes contact with the plunger. When the valve and plunger are properly engaged, flat-to-flat, the valve and plunger cannot be rotated. Exert a GENTLE downward pressure on the assist cylinder and valve assembly and at the same time, slowly EASE the propeller shaft backward to engage the plunger keyway with the push rod key. The gentle downward pressure on the shift assist assembly will help the push rod key to slip into the plunger keyway. After the proper alignment has been made, as just described, push the propeller shaft and shift assist assembly inward until full engagement is reached. When the propeller shaft and the shift ass..st assembly are properly engaged, the ass1s t valve and push rod CANNOT be rotated. Solenoid Cover and Gasket -Installation 26-Slide the solenoid cover up onto the upper part of the shift rod, and then place a NEW gasket into place on the bottom side of the cover. Thread the shift rod into the valve assembly in the assist solenoid. Rotate the shift rod inward abou t three complete turns for a rough preliminary adjustment. Check to be sure the unit is in NEUTRAL. Now, measure the distance from the top of the housing to the center of the hole in the shift rod, reference illustration ''D". This distance must be within 1/32" (0.8mm) as follows for a 1973 or 1974 model. Long shaft --21 7 /32" 54.6cm Short shaft --16 7/32" 4l.9cm Rotate the shift rod inward or outward until the required measurement is obtained. Lower the cover and gasket down on to the lower unit housing. Secure the cover in place with the attaching hardware. Tighten the bolts ALTERNATELY and EVENLY. Reverse Gear -Installation 27-Apply a light coating of grease to the inside surface of the reverse gear to hold the thrust washer in place. Place the thrust washer onto the front side of the reverse gear. Install the thrust bearing and thrust washer onto the shank on the back side of the reverse gear. Slide the reverse gear down the propeller shaft and index the teeth of the gear with the teeth of the pinion gear. 28-Insert the retainer pia te into the lower unit against the reverse gear. WARNING This next step can be dangerous. Each snap ring is placed under tremendous tension MECH SHIFT HYD ASSIST 8-165 with the Truarc pliers while it is being placed into the groove. Therefore, wear SAFETY GLASSES and exercise care to prevent the snap ring from slipping out of the pliers. If the snap ring should slip out, it would travel with incredible speed and cause personal injury if it struck a person. 29-Install the Truarc snap rings one ata- time following the precautions given in the WARNING and the ADVICE given in the following paragraph. WORDS OF ADVICE The two snap rings index into separate grooves in the lower unit housing. As the first ring is being installed, depth perception may play a trick on yours eyes. It may appear that the first ring is properly indexed all the way around in the proper groove, when in reality, a portion may be in one groove and the remainder in the other groove. Should this happen, and the Truarc pliers be released from the ring, it is extremely difficult to get the pliers back into the ring to correct the condition. If necessary use a flashlight and carefully check to be sure the first ring is properly seated all the way around BEFORE releasing the grip 8-166 LOWER UNIT View into the lower unit showing the Truarc snap rinqs properly locked in the grooves. on the pliers. Installation of the second ring is not so difficult because the one groove is filled with the first ring. 30-Obtain two long 1/4" rods with threads on one end. Thread the rods into the retainer plate opposite each other to act as guides for the bearing carrier. 31-Check the bearing carrier to be sure a NEW 0-ring has been installed. Position the carrier over the guide pins with the embossed word UP on the rim of the carrier facing UP in relation to the lower unit housing, reference illustration ''E". Now, lower the bearing carrier clown over the guide pins and into place in the lower unit housing. 32-Slide NEW little 0-rings onto each bolt, and apply some OMC Sealer onto the threads. Install the bolts through the carrier and into the retaining plate. After a couple bolts are in place, remove the guide M.ECH SHIFT HYD ASSIST 8-167 pins and install the remaining bolts. Tighten the bolts EVENLY and ALTERNATELY to the torque value given in the Appendix. WATER PUMP INSTALLATION FIRST, THESE WORDS An improved water pump is available as a replacement. If the old water pump housing is unfit for further service, only the new pump housing can be purchased. It is strongly recommended to replace the water pump with the improved model while the lower unit is disassembled. The accompanying illustration shows the original equipment (left) compared with the improved pump(right), reference illustration "F". The new pump must be assembled before it is installed. Therefore, the following steps outline procedures for both pumps. To assemble and install a replacement pump, perform steps 33 thru 41, then jump to Step 46. To install an original equipment pump, proceed directly to Step 42. Assembling an Improved Pump Housing 33-Remove the water pump parts from the container. Insert the plate into the housing, as shown. The tan.. on the bottom side of the plate MUST index into the short slot in the pump housing. 34-Slide the pump liner into the housing with the two small tabs on the bottom side indexed into the two cutouts in the plate. 35-Coat the inside diameter of the liner with light-weight o.il. v'.''ork the impeller into the housing with all of the blades bent back to the right, as shown. In this position, the blades will rotate properly when the pump housing is installed. Remember, the pump and the blades will be rotating CLOCKWISE when the housing is turned over and installed in place on the lower unit. 8-168 LOWER UNIT 36-Coat the mating surface of the lower unit with 1000 Sealer. Slide the water pump base plate down the driveshaft and into place on the lower unit. Insert the Woodruff key into the key slot in the driveshaft. 37-Lay down a very thin bead of 1000 sealer into the irregular shaped groove in the housing. Insert the seal into the groove, and then coat the seal with the 1000 Sealer. Water Pump Installation 38-Begin to slide the \Vater pump down the driveshaft, and at the same time observe the position of the slot in the impeller. Continue to work the pump down the driveshaft, with the slot in the impeller indexed over the Woodruff key. The pump must be fairly well aligned before the key is covered because the slot in the impeller is not visible as the pump begins to come close to the base plate. 39-Install the short forward bolt through the pump and into the lower unit. DO NOT tighten this bolt at this time. Insert the grommet into the pump housing. 40-Install the grommet retainer and water tube guide onto the pump housing. Install the remaining pump attaching bolts. Tighten the bolts ALTERNATELY and EVENLY, and at the same time rotate the driveshaft CLOCKWISE. If the driveshaft is not rotated while the attaching bolts are being tightened, it is possible to pinch one of the impeller blades underneath the housing. MECH SHIFT HYD ASSIST 8-169 41-Slide the large grommet down the driveshaft and seat it over the pump collar. This grommet does not require sealer. Its function is to prevent exhaust gases from entering the water pump. Proceed directly to Lower Unit Installation, Step 44. Water Pump Installation Original Equipment Perform the following two steps to install an original water pump. 42-Coat the water pump plate mating surface on the lower unit with 1000 Sealer. Slide the water pump plate down the driveshaft and BEFORE it makes contact with the sealer check to be sure the bolt holes in the plate will align with the holes in the housing. The plate will only fit one way. If the holes will not align, remove the plate, turn it over and again slide the plate down the driveshaft and into place on the housing. This checking will prevent accidently getting the sealer on both sicles of the plate. If by chance sealer does get on the top surface it MUST be removed before the water pump impeller is installed. Slide the water pump impeller down the driveshaft. Just before the impeller covers the cutout for the Woodruff key, install the key, and then work the impeller on down, with the slot in the impeller indexed over the Woodruff key. Continue working the impeller down until it is firmly in place on the surface of the pump plate. 43-Check to be sure NEW seals and 0rings have been installed in the water pump. Lubricate the inside surface of the water pump with light-weight oil. Lower the water pump housing down the driveshaft and over the impeller. ALWAYS rotate the driveshaft slowly CLOCKWISE as the housing is lowered over the impeller to allow the impeller blades to assume their natural and 8-170 LOWER UNIT proper position inside the housing. Continue to rotate the dr iveshaft and work the water pump housing downward until it is seated on the plate. Coat the threads of the water pump attaching screws with sealer, and then secure the pump in place with the screws. Install the solenoid cable bracket with the same bolt and in the same position from which it was removed. On some units the solenoid cable fits into a recess of the water pump and is held in place in that manner. Tighten the screws ALTERNATELY and EVENLY. LOWER UNIT INSTALLATION 44-Check to be sure the water tubes are clean, smooth, and free of any corrosion. Coat the water pickup tubes and grommets with lubricant as an aid to installation. Check to be sure the spark plug wires are disconnected from the spark plugs. Bring the lower unit housing together with the exhaust housing, and at the same time, guide the water tube into the rubber grommet of the water pump. Continue to bring the two units together, at the same time guiding the water pickup tubes into the rubber grommet of the water pump, and, simultaneously rotating the flywheel slowly to permit the splines of the driveshaft to index with the splines of the crankshaft. This may sound like it is necessary to do four things at the same time, and so it is. Therefore, make an earnest attempt to secure the services of an assistant for this task. 45-After the surfaces of the lower unit and exhaust housing are close, dip the attaching bolts in OMC Sealer and then start them in place. Install the two bolts on each side of the two housings. Install the bolt in the recess of the trim tab. Install the bolt just forward of the trim tab that extends up through the cavitation plate. Tighten the bolts ALTERNATELY and EVENLY to the torque value given in the Appendix. 46-Install the trim tab with the mark made on·the tab during disassembling align ed with the mark made on the lower unit housing. 47-The shift rod is visible beneath and to the rear of the lower carburetor. Install the shift connector with a bolt or pin, depending on the model being serviced. Filling the Lower Unit Fill the lower unit with lubricant according to the procedures in Section 8-3. Propeller Installation Install the propeller, see Section 8-2. FUNCTIONAL CHECK Perform a functional check of the completed work by mounting the engine in a test tank, in a body of water, or with a flush attachment connected to the lower unit. If the flush attachment is used, NEVER operate the engine above an idle speed, because the no-load condition on the propeller would allow the engine to RUNAWAY resulting in serious damage or destruction of the engine. CAUTION: Water must circulate through the lower unit to the engine any time the engine is run to prevent damage to the water pump in the lower unit. Just five seconds without water will damage the water pump. MECH SHIFT 40t-f> TO 60t-f> 8-171 Start the engine and observe the tattletale flow of water from idle relief in the exhaust housing. The water pump installation work is verified. If a "Flushette" is connected to the lower unit, VERY LITTLE water will be visible from the idle relief port. Shift the engine into the three g:ears and check ior smoothness of operation and satisfactory performance. Remember, v.. hen the unit is in forward gear, it is at rest with no current flow to either solenoid. 8-13 MECHANICAL SHIFT SHIFT DISCONNECT UNDER LOWER CARBURETOR 40 HP 1976 AND ON 50 HP 1972-73 50 HP 1975 and 1980 AND ON 55 HP 1975-83 60 HP 1910-85 DESCRIPTION The lower unit covered in this section is complete mechanical shift unit. A shift cable connects the shift box to the shift linkage at the engine. A shift rod extends from the engine down through the exhaust housing to the lower unit. Shifting into forward, neutral, and reverse, is accomplished directly through mechanical means from the shift control handle through the cable and linkage to the dutch dog in the lower unit. The lmver unit houses the driveshaft and pinion gear' the forward anc reverse driven gears, the propeller shaft, shift lever, cradle, shift shaft, clutch dog, shift rod, and the necessary shims, bearings, and associated parts to make it all work properly. A detent ball and spring is installed on some models. The water pump is considered a part of the lower unit. Two different lower units are covered in this section. One unit is used with the electric start model and the other with manual start. The model years actually overlap. The upper driveshaft bearing and the shift mechanism differ between the two units. These differences are clearly indicated in the procedural steps and illustrations. TROUBLESHOOTING Preliminary Checks At rest, and without the engine running, the lower unit is in forward gear. i\'iount the engine in a test tank, in a body of water, or 8-172 LOWER UNIT with a flush attachment connected to the lower unit. If the flush attachment is used, NEVER operate the engine above an idle speed, because the no-load condition on the propeller would allow the engine to RUNAWAY, resulting in serious damage or destrue tion of the engine. CAUTION: Water must circulate through the lower unit to the engine any time the engine is run to preven t damage to the water pump in the lower unit. Just five seconds without water will damage the water pump. Attempt to shift the unit into NEUTRAL and REVERSE. It is possible the propeller may turn very slowly while the unit is in neutral, due to "drag" through the various gears and bearings. If difficult shif ting is encountered, the problem is in the shift linkage or in the lower unit. The second area to check is the quantity and quality of the lubricant in the lower unit. If the lubricant level is low, contaminated with water, or is broken down because of overuse, the shift mechanism may be affected. Water in the lower unit is VERY BAD NEWS for a number of reasons, particularly when the lower unit contains hydraulic components. Hydraulic units will not func tion with water in the system. Remember, when the engine is not running, the unit should be in FOR WARD gear. BEFORE making any tests, remove the propeller, see Section 8-2. Check the propeller carefully to determine if the hub has been slipping and g1vmg a false indication the unit is not in gear, reference illustration "A". If there is any doubt, the propeller should be taken to a shop properly equipped for testing, before the time and expense of disassembling the lower unit is undertaken. The expense of the propeller testing and possible rebuild is justified. The following troubleshooting procedures are presented on the assumption the lower unit lubricant, and the propeller have been checked and found to be satisfactory. Helm-type shift box and steering wheel. Lower Unit Locked Determine if the problem is in the powerhead or in the lower unit. Attempt to rotate the flywheel. If the flywheel can be moved even slightly in either direction, the problem is most likely in the lower unit. If it is not possible to rotate the flywheel, the problem is a "frozen" powerhead. To absolutely verify the powerheacl is "frozen", separate the lower unit from the exhaust housing and then again attempt to rotate the flywheel. If the attempt is successful, the problem is definitely in the lower unit. If the attempt to rotate the flywheel, with the lower unit removed, still fails, a "frozen" powerhead is verified, reference illustration "B". Unit Fails to Shift Neutral, Forward, or Reverse With the outboard mounted on a boat, in a test tank, or with a flush attachment connected, disconnect the shift lever at the engine. Attempt to manually shift the unit into NEUTRAL, REVERSE, FOR WARD. At the same time move the shift handle at the shift box and determine that the linkage and shift lever are properly aligned for the shift Shift and throttle linkage on the 50 hp, 197 3-7 4 engines. MECH SHIFT 40f-P TO 60HP 8-1 73 positions. If the alignment is not correct, adjust the shift cable at the trunnion. It is also possible the inner wire may have slip ped in the connector at the shift box. This condition would result in a lack of inner cable to make a complete "throw" on the shift handle. Check to be sure the shift handle is moved to the full shift position and the linkage to the 10wer unit is moved to the full shift position. If an adjustment is required at the shift box, see Chapter 7. If it is not possible to shift the unit into gear by manually operating the shift rod while the engine is running, the lower unit requires service as described in this section. LOWER UNIT SERVICE Propeller Removal If the propeller was no t removed, as directed for the troubleshooting, remove it now, according to the procedures outlined in Section 8-2. Draining the Lower Unit Drain the lower unit of lubricant, see Section 8-3. GOOD WORDS If wa ter is discovered in the lower unit and the propeller shaft seal is damaged and requires replacement, the lower unit does NOT have to be removed in order to accomplish the work. The bearing carrier can be removed and the seal replaced without disassembling the lower unit. HOWEVER, such a procedure is not considered good shop practice, but merely a quick-fix. If water has entered the lower unit, the unit should be disassembled and a detailed check made to determine if any other seals, bearings, bearing races, 0rings or other parts have been rendered unfit for further service by the water. LOWER UNIT REMOVAL 1-Disconnect and ground the spark plug wires. Remove the starter motor. Remove the bol t or bol ts from the shift connector under the lower carburetor. 2-Scribe a mark on the trim tab and a matching mark on the lower unit to ensure the trim tab will be installed in the same position from which it is removed. Use an Allen wrench and remove the trim tab. 8-174 LOWER UNIT 3-On some units, an attaching bolt is installed inside the trim tab cavity. Use a 1/2" socket with a short extension and remove this bolt. Failure to remove this bolt from inside the trim tab cavity may result in an expensive part being broken in an attempt to separate the lower unit from the exhaust housing. Remove the 5/8" countersunk bolt located just ahead of the trim tab position. 4-Remove the four 9/16" bolts, two on each side, securing the lower unit to the exhaust housing. \\fork the lower unit free of the exhaust housing. If the unit is still mounted on a boat, tilt the engine forward to gain clearance between the lower unit and the deck (floor, ground, whatever). EXERCISE CARE to withdraw the lower unit straight away from the exhaust housing to prevent bending the driveshaft. into the meta! of the into the meta! of the carrier rim. This word must face UP in relation to the lower unit during installation. 9-Remove the bearing carrier using one of the methods described in the following paragraphs, under Special Words. WATER PUMP REMOVAL 5-Position the lower unit in the vertical position on the edge of the work bench resting on the cavitation plate. Secure the lower unit in this position with a C-clamp. The lower unit will then be held firmly in a favorable position during the service work. An alternate method is to cut a groove in a short piece of 2" x 6" wood to accommodate the lower unit with the cavitation plate resting on top of the wood. Clamp the wood in a vise and service work may then be performed with the lower unit erect (in its normal position), or inverted (upside down). In both positions, the cavitation plate is the supporting surface. 6-Remove the 0-ring from the top of the driveshaft. Remove the bolts securing the water pump to the lower unit housing. Pull the water pump housing up and free of the driveshaft. Slide the water pump impeller up and free of the driveshaft. 7-Pop the impeller Woodruff key out of the driveshaft keyway. Slide the water pump base plate up and off of the driveshaft. GOOD WORDS If the Bearing Carrier bolt has removed. 2" X 4" WOODEN BLOCK only work to be performed is service of the water pump, proceed directly to Page 8-1 93, Water Pump Installation. Removal Remove the four 5/16" bolts from inside the bearing carrier. Notice how each an 0-ring seal. These 0-rings should be replaced each time the bolts are In most cases, the word UP is MECH SHFT 401-P TO 601-P 8-175 embossed bearing person. Therefore, con tinue to hold the ring and pliers firm after the ring is ou t of the groove and clear of the lower unit. Place and gear case without allowing the pliers to slip. Release the grip on the pliers in the manner described in the above WARNING. Remove the second retaining ring in the same manner. The rings are identical ancl either one may be installed first. person. Therefore, con tinue to hold the ring and pliers firm after the ring is ou t of the groove and clear of the lower unit. Place and gear case without allowing the pliers to slip. Release the grip on the pliers in the manner described in the above WARNING. Remove the second retaining ring in the same manner. The rings are identical ancl either one may be installed first. 8-176 LOWER UNIT SPECIAL WORDS Several models of bearing carriers are used on the lower units covered in this section. The bearing carriers fit very tightly into the lower ,unit opening. Therefore, it is not uncommon to apply heat to the outside surface of the lower unit with a torch, at the same time the puller is being worked to remove the carrier. TAKE CARE not to overheat the lower unit. One model carrier has two threaded holes on the end of the carrier. These threads permit the installation of two long bolts. These bolts will then allow the use of a flywheel puller to remove the bearing carrier, ill us tra tion "9". Another model does not have the threaded screw holes. To remove this type bearing carrier, a special puller with arms must be used. The arms are hooked onto the carrier web area, and then the carrier removed, reference illustration "C". WARNING The next step involves a dangerous procedure and should be executed with care while wearing SAFETY GLASSES. The retaining rings are under tremendous tension in the groove and while they are being removed. If a ring should slip off the Truarc pliers, it will travel with incredible speed causing personal injury if it should strike a the ring on the floor and hold it securely w.ith one foot before releasing the grip on the pliers. An alternate method is to hold the ring inside a trash barrel, or other suitable container, before releasing the pliers. 10-Obtain a pair of Truarc pliers. Insert the tips of the pliers into the holes of the first retaining ring. Now, CAREFULLY remove the retaining ring from the groove MECH SHIFT 401-P TO 60HP 8-177 11-Remove the retainer plate, thrust washer, thrust bearing, and reverse gear from the propeller shaft. 12-Remove the four bolts from the driveshaft bearing housing. Pull up on the shift rod. This action will place shift dog into the forward gear position. Rotate the propeller shaft a bit as a check to be sure the unit is in forward gear. Pinion Gear Removal - Special tool, OMC No. 316612 is required to turn the driveshaft in order to remove the pinion gear nut. 13-Obtain the special tool and slip it over the end of the clriveshaft with the splines of the tool indexed with the splines on the driveshaft. Hold the pinion gear nut with the proper size wrench, and at the same time rotate the driveshaft, with the special tool and wrench COUNTERCLOCKWISE until the nut is free. If the special tool is not available, damp the driveshaft in a vise equipped with soft jaws, in an area below the splines but not in the water pump impeller area. Now, with the proper size wrench on the pinion gear nut, rotate the complete lower unit COUNTERCLOCKWISE until the nut is free. This procedure will require the lower unit to be rotated, then the wrench released, the lower unit turned back, the wrench again attached to the nut, and the unit rotated again. Continue with this little maneuver until the nut is free. After the nut is free, proceed with the next step. The driveshaft will be withdrawn from the pinion gear. Driveshaft -Removal 14-CAREFULLY pry the bearing housing upward away from the lower unit, then slide it free of the driveshaft. An alternate method is to again clamp the driveshaft in a vise equipped with soft jaws. Use a softheaded mallet and tap on the top side of the bearing housing. This action will jar the housing loose from the lower unit. Continue tapping with the mallet and the bearing housing, 0-rings, shims, thrust washer, thrust bearing, and the driveshaft will all breakaway from the lower unit and may be removed as an assembly. As the driveshaft is removed, reach into the lower unit, catch, and remove the pinion gear. @ shaft and thread the propeller nut onto the shaft. nate method is to clamp special tool OMC No. 387206 to the driveshaft just above the shoulder. Now, invert the driveshaft ancl shaft and thread the propeller nut onto the shaft. nate method is to clamp special tool OMC No. 387206 to the driveshaft just above the shoulder. Now, invert the driveshaft ancl 8-178 LOWER UNIT 15-Push on the shift rod to move the unit into the reverse gear position. Remove the four bol ts securing the shift rod cover. Rotate the shift rod COUNTERCLOCKWISE until it is free of the shifter detent in the lower unit. Remove the shift rod and cover as an assembly. As the plate is removed, notice which surface is facing into the housing, as an aid during installation. Propeller Shaft -Removal 16-Grasp the propeller shaft firmly with one hand and remove the propeller shaft from the lower unit. The forward gear, and bearing housing will come out with the shaft as an assembly. "FROZEN" PROPELLER SHAFT On rare occasions, especially if water has been allowed to enter the lower unit, it may not be possible to withdraw the propeller shaft as described in Step 16. The shaft may be "frozen" in the hydraulic pump due to corrosion. If efforts to remove the propeller shaft after the bearing carrier has been removed fail: Two methods are available to free the propeller shaft from the lower unit. The first and safest method is to obtain a block of wood 2"x 4" approx. one foot in length. Drill a hole in the center of the flat side, large enough for the propeller shaft to pass through. Place the block over the shaft. Slide some thick large washers over the With the skeg clamped securely in a vise equipped with soft jaws, attempt to pull the shaft free. If necessary hammer on the wood, rotating the block at intervals to prevent wedging the shaft in any one direction. The second and less desirable method is as follows: Clamp the propeller shaft horizontally in a vise equipped with soft jaws. Two blocks of wood may be substituted for the soft jaws, bu t NEVER clamp the shaft in the vise without protection, to prevent darnage to the threads or sp!.ines. Use a soft head mallet and strike the lower unit with quick sharp blows midway between the anticavitation plate and the propeller shaft. This action will drive the lower unit from the propeller shaft. TAKE CARE to hold the lower unit to keep it in line with the propeller shaft and prevent wedging the shaft in any one direction. Holding the lower unit will also prevent the housing from falling to the floor when the housing comes free of the shaft. Driveshaft Disassembling For Unit On Page 184 ONLY 17-The driveshaft upper bearing anc' cone are replaced as an assembly. If replacement is required, obtain special tool OMC No. 387131. Clamp the tool below the bearing, and then place the unit in an arbor press equipped ·with a deep throat pedestal. Press the shaft from the bearing. An alter MECH SHIFT 40 1-P T0 601-P 8-1 79 place it in an arbor press with special tool OMC No. 387206 seated on the press. Place a piece of pipe over the driveshaft, and then press against tool OMC No. 387131 to remove the bearing. Bearing Carrier -Disassembling INSPECTION FIRST The bearings in the carrier need NOT be removed unless they are unfit for further service. Insert a finger and rotate the bearing. Check for "rough" spots or binding. Inspect the bearing for signs of corrosion or other types of damage. If the bearings must be replaced, proceed with the next step. 18-Use a seal remover to remove the two back-to-back seals or damp the carrier in a vise and use a pry bar to pop each seal out. 19-Use a drift punch to drive the bearings free of the carrier. The bearings are being removed because they are unfit for service, therefore, additional damage is of no consequence. Propeller Shaft --Disassembling 20-Remove the coil spring from the outside groove of the clutch dog. EXERCISE CARE not to distort the spring as it is removed. Remove the dutch dog pin by PIPE ,-----, I I I I I I SPEC IAl I TOOL II No. 387 131 II I SPEC IAL L_ __j TOOL BEAR ING No. 387206 ® 8-180 LOWER UNIT pushing it through the clutch dog and propeller shaft. This pin is not a tight fit, therefore, it is not difficult to remove. Grasp the propeller shaft and pull it free of the bearing housing. SPECIAL WORDS Two different shifter arrangements on the propeller shaft are used on the units covered in this section. An exploded draw ing of one type is shown on Page 8-183 together with reference illustration "0" on Page 180. An exploded drawing of the other lower unit will be found on Page 8-184 together with reference illustration "E" on Page 181. Take special notice of how one type has a shifter shaft, bearing, one detent ball, and one spring. The other model has a clutch dog shaft, thrust washer, and two detent balls and springs. Compare the pro peller shaft from the unit being serviced with the two drawings. Now, if the unit being serviced is the one shown on Page 8-183, perform Steps 21 and 22, then skip to Step 26. If the unit being serviced is the one shown on Page 8-1 84, skip to Step 23 and perform the work thru Step 25, then contin ue with Step 26. NOTE: The following two steps are to be performed if servicing a unit as illustrated on Page 8-183 and reference illustration ''0·. THRUST WASHE R I I FORWARD GEAR THRUST BEARING 21-Remove the two Allen screws from the back side of the bearing housing and at the same time be prepared to catch the two detent balls and springs. 22-Remove the shift lever pin. Remove the shift lever and shifter detent, from the bearing housing. Remove the shifter shaft. PIN Y / / / ..SHIFT LEVER / BEARING HOUSING DETENT SET SCRE'A I 0 BALLS SPRING SET SCREW ® MECH SHIFT 40rP TO 60HP 8-181 ® NOTE: The following three steps are to be performed if servicing a unit as illustrated on Page 8-1 84 and reference illustration "E". 23-Remove the shift lever pin and disengage the shift lever from the cradle in the shift shaft. 24-Remove the shifter shaft and cradle. Remove the shift lever. SAFETY WORD The next step is dangerous. The detent balls are under tension from the springs. The balls are released with pressure. Therefore, SAFETY GLASSES should be worn as personal protection for the eyes. 25-Observe the short arm at the upper end of the shifter detent. Now, rotate the shifter detent until this arm is 180 ° from its original position (facing toward the opposite direction). Rotating the shifter detent 180 ° will depress the detent ball and spring. From this position, work the shifter detent up out of the housing. SHIFT GEAR I SHAFT / DETENT .. PIN DETENT BALL .. DETENT SPRING BEARING HOUSING ® special tool, 0./1C No. 385546. If servicing a unit shown in the exploded drawing on Page 8-184, obtain special tool, OIV1C No. AllEN SCREW special tool, 0./1C No. 385546. If servicing a unit shown in the exploded drawing on Page 8-184, obtain special tool, OIV1C No. AllEN SCREW 8-182 LOWER UNIT Lower Driveshaft Bearing -Removal SPECIAL WORDS Two different type bearings are used on the lower unit models covered i.n this section. Exploded drawings of both type bearings are given on Page 8-183 and Page 8 184. To determine which type bearing is used on the unit being serviced, check the shifter arrangement on the propeller shaft and compare it \Vith the two illustrations. A special tool MUST be used to remove either type bearing. Therefore, DO NOT attempt to remove this bearing unless it is unfit for further service. To check the bearing, first use a flashlight a.nc! inspect it for corrosion or other damage. Insert a finger into the bearing, and then check for "rough" spots or binding while rotating i.t. 26-Remove the Allen screw, from the water pickup slots in the starboard side of the lower unit housing. Th.is screw secures the bearing in place and MUST be removed before an attempt is made to remove the bearing. The bearing must be actually "PULLED" upward to come free. NEVER make an attempt to "drive" it down and out. 27-If servicing a unit shown in the exploded i.llustration on Page 183, obtain 391 257. Use the special tool and "pull" the bearing from the lower unit. CLEANING AND INSPECTING \Yash all parts in solvent and dry them with compressed air. Discard all 0-rings and seals that have been removed. A new seal ki.t for this lower unit is available from the local dealer. The kit will contain the necessary seals and 0-rings to restore the lower unit to service. Inspect all splines on shafts and in gears for wear9 rounded edges, corrosion, and damage. Carefully check the drivesha.ft and the propeller shaft to verify they are straight and true without any sign of damage. A complete check must be performed by turning the shaft in a lathe. Thi.s is only necessary if there is evidence to suspect the shaft is not true. Check the water pump housing for corrosion on the inside and verify the impeller and base plate are in good condition. Actually, good shop practice dictates to rebuild or replace the water pump each time the lower unit is disassembled. The small cost is rewarded with "peace of mir.d" and satisfactory service. MECH SHIFT 401-P TO 601-P 8-183 DRIVESHAFT OIL "0" RING RETAINER GROMMET I :-..;r---I ' -... --. -... 6IS .. EAL "0" RING TUBE I GEAR CASE SHIFT ROD I I1 I I I 1 I II a---BUSHING o-"O" R!NG Ii I r--. I L-- I III .?'.... I..IQ) J DRIVESHAFT I "" PINION BEARING SET SCREW I BEARING PINION THRUSTWASHER I : i I II NUT PROPELLER SHAFT PIN I I CLUTCH '- DOG --.. PINY ...._ ..THRUST BEARING dn·..@/THRUS t , u ....._ -... L ./ I SHI FT ER SHAFT RETAININ --....._ · , SEAL I DLE BEARING ....._ 0 DETENT 1I SCREWI i - "0" RING \ . I ---I G G --.RINGS ---... BEARING SET SCREW- -... --. ....._ ...._ - - PLATE PR....J}i-" RETOIL AINER BEARING Exploded drawing of one of two lower units coverec in this section. This unit has a thrust bearing and thrust washer on the driveshaft and two detent balls and springs for the shift mechanism. Enlarged cletails of the shift mechanism are shown in reference illustration "D" on Page 8-180. Numerous references in the text are made to these two illustrations. 8-184 LOWER UNIT (SHCRT SHAFT .. ../LY) A_::> ONLY H) DRIVESHAFT OIL :---------- "0/RING o .__.__ --.. I li I I I .__--.--. ..· . -SEAL (LCNG SEAL ..OUSING R'NG ! I GROMMET WATER TL:BE BRACKET I HOUSING 1I ..._ ..._ .__ ONLY) BEARING SCREEN- . ;: I 1 c?..IJ ....