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QUICK MENU CLICK FOR CHAPTER 1 TABLE OF CONTENTS 2 MAINTENANCE 3 FUEL SYSTEM 4 IGNITION AND ELECTRICAL 5 LUBRICATION AND COOLING 6 POWERHEAD 7 LOWER UNIT 8 TRIM AND TILT 9 REMOTE CONTROLS 10 HAND STARTERS 11 MODELS COVERED ANODES (ZINCS). . . . . . . . . . . . . . . . . . . . 2-25 MAINTENANCE EQUALS SAFETY. . . . . . . . 2-2• INSPECTION . . . . . . . . .. .. • . . . . . . . . . . 2-26 OUTBOARDS ON SAIL BOATS. . . . . . . . . . . 2ˇ2 SERVICING . . . . . . . . . . . . 2-26. . . . . . . . . . . • POWER TRIMfTILT RESERVOIR . . . . . . . . . 2ˇ9 BATIERIES. . . . . . . . . . . . . . . . . . . . . . . . . . 2-27 FLUID LEVEUCONDITION . . . . . . . . . . . . . MAINTENANCE . .. .. . .. . . • . . . . . . . . . . 2-27 RECOMMENDED LUBRICANT . . . . . . . . . . STORAGE . . . . . . . . . . . . . . . . . . . . . . . . . 2-29 TESTING . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28 BEFORE/AFTER EACH USE . . . . . . . . . . . . 2-4 VISUALLY INSPECTING THE BOAT AND MOTOR . . . ... . . . . . . . . . . . . . . . . . . 2-4 BOAT MAINTENANCE . . . . • . . • . . . • . • . . . 2-27 BATIERIES . . . . . . . . . . . . . . . . . . . . . . . . 2-27 FIBERGLASS HULL . . . . . . . . . . . . . . . . . . 2-29 INTERIOR. . . . . . . . . . . . . . . . . . . . . . . . . . 2-30 CLEARING A SUBMERGED MOTOR. . . . . . 2-87 COMPRESSION TESTING . . . . . . . . . . . . . . 2-32 COMPRESSION CHECK . . . . . . . . . . . . . . 2-32 LOW COMPRESSION. . . . . . . . . . . . . . . . . 2-33 COOLING SYSTEM ................... 2-11 FLUSHING JET DRIVES ............... 2-13 FLUSHING THE COOLING SYSTEM ..... 2-11 ELECTRICAL SYSTEM CHECKS . . . . . . . . . 2-38 CHECKING THE BATIERY. . . . . . . . . . . . . 2ˇ38 CHECKING THE INTERNAL . WIRING HARNESS ................... 2-39 CHECKING THE STARTER MOTOR. . . . . . 2-39 ELECTRONIC IGNITION SYSTEMS ....... 2-38 ENGINE COVERS ........ ........ ..... 2-10 REMOVAL & INSTALLATION ........... 2-10 ENGINE IDENTIFICATION . . . . . . . . . . . . . . 2-2 ENGINE MODEL & SERIAL NUMBERS . . . 2-3 ENGINE MAINTENANCE .•.•.••.•••.... 2-10 ANODES (ZINCS). . . . . . . . . .• . . . . . . . . . 2-25 COOLING SYSTEM .................. 2-11 ENGINE COVERS ................... 2ˇ10 ENGINE OIL .. . . . . . . . .. .. . . . . . . . . .. . 2-13 FUEL FILTER ....................... 2-15 JET DRIVE IMPELLER . . . . . . . . . . . . . . . . 2-24 PROPELLER. . . . . . . . . . . . . . . . . . . . . .. . 2-18 ENGINE OIL .............. ........... 2-13 CHECKING ......................... 2-15 FILLING . . . .. . . . . . . .. . . .. . .. . . . . . . . 2-14 OIL RECOMMENDATIONS ............. 2ˇ13 FIBERGLASS HULL . . . . 2-29 . . . . . . . . . . . . . . • FUEL FILTER ........................ 2-15 FUEL SYSTEM CHECKS . . . . . . . . . . . . . . . 2-39 GEARCASE (LOWER UNIT) OIL.......... 2-7 CHECKING LEVEL & CONDITION . . . . . . . 2-7 DRAINING AND FILLING . . . . . . . . . . . . . . 2-8 OIL RECOMMENDATIONS. . . . . . . . . . . . . 2-7 GENERAL INFORMATION • • • • . . . • .. . . . . 2-2 BEFORE/AFTER EACH USE . ... . . • . . . . 2ˇ4 ENGINE IDENTIFICATION . . . . . . . . . . . . . 2-2 MAINTENANCE COVERAGE IN THIS MANUAL . . . . . . . . . . . . . . . . . . . . . . 2-2 MAINTENANCE EQUALS SAFETY. . . . . . . 2ˇ2 OUTBOARDS ON SAIL BOATS . . . . . . . . . 2-2 IDLE SPEED ADJUSTMENT. . . . . . . . . . . . . 2-43 INTERIOR. . . . .. .. . .. . . . . . . .. . .. . . .. . 2-30 INTRODUCTION TO TUNE-UPS .... ...... 2-30 JET DRIVE BEARING . . . . . . . . . . . . . . . . . . 2-9 PREPPING THE MOTOR . . . . . . . . . . . . . . . 2-44 TACHOMETER CONNECTIONS. . . . . . . . . 2-45 PROPELLER ......................... 2-18 GENERAL INFORMATION ............. 2-18 INSPECTION . . . . . . . . . . . . . . . . . . . . . . . 2-21 REMOVAL & INSTALLATION ........... 2-21 RE-COMMISSIONING ....... ........... 2-86 SPARK PLUG WIRES. . . . . . . . . . . . . . . . . . 2-38 REMOVAL & INSTALLATION 2-38 ...•....... TESTING . . . . . .. .. .. . . .. . .. . . . . . . . . 2-38 SPARK PLUGS. . . . .. . ... .. • . . • . . . . . 2ˇ33 . . HEAT RANGE ....................... 2-34 INSPECTION & GAPPING . . . . . . . . . . . . . 2-37 REMOVAL & INSTALLATION ....... .... 2-34 READING SPARK PLUGS . . . . . . . . . . . . . 2ˇ36 SPECIFICATIONS. . • . . . . . . • . . • . . • • . . • . 2-88 CAPACITIES .. :..................•.. . 2ˇ96 ENGINE ..... . . . •. . . • . . . . . . . . . . . . . . 2-91 LUBRICATION . . . . . . . . . . . . . . . . . . . . . . 2-95 MAINTENANCE INTERVALS . . . . . . . . . . . 2-90 TUNE-UP . . . . . . . . . . . . . . . . . . . . . . . . . . 2-88 STORAGE 2-84 . .. . • • . • • • • . • • • . • . • . . . • . • • RE-COMMISSIONING. . . . . . . . . . . . . . . . . 2-86 WINTERIZATION .................... 2-84 SYNCHRONIZATION . . . . . . . . . . . . . . . . . . 2-44 TIMING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-44 TIMING AND SYNCHRONIZATION ..•.•.•. 2-44 GENERAL INFORMATION . . . . . . . . . . . . . 2-44 PREPPING THE MOTOR . . . . . . . . . . . . . . 2-44 SYNCHRONIZATION . . . . . . . . . . . . . . . . . 2-44 TIMING. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2ˇ44 2 HP MODEL . . . . . . . . . . . . . . . . . . . . . . . 2-45 3 HP MODEL . . . . . . . . . . . . . . . . . . . . . . . 2-45 4/5 HP (83 AND 103CC) MODELS . . . . . . . 2-46 6/8 HP MODELS. .. . . . . . . . . . . .. . . . . . . 2-47 9.9/15 HP MODELS .................. 2-49 20/25 HP (395CC) MODELS ....... ..... 2-51 20/25 HP (430CC) MODELS. . . . . . 2-53 . . . . . • 25/30 HP (496CC . . . . . . . . . . . . . . . . . . . . 2 CYLINDER) MODELS. . . . . . . . . . . . . . . . . 2-54 40 HP (2-CYLINDER) MODEL. . . . . . . . . . . 2-54 48 HP (2-CYLINDER) MODELS ......... 2-57 25/30 HP (496CC 3-CYLINDER) MODELS . 2-61 28J-50 HP (698CC) MODELS . . . . . . . . . . . 2-66 50-70 HP (849CC) AND 65J-90 HP (1140CC) MODELS ................... 2-68 E60 (849CC) AND E75, E75A, 85A, E60J (1140CC) MOTORS .................. 2-70 V4 AND V6 CARBURETED MOTORS ..... 2-74BEARING LUBRICATION . .. . . . . . . . . . . . V6 EFI (OX66) AND HPDI MOTORS . . . . . . 2-79GREASE REPLACEMENT . . . . . . . . . . . . . RECOMMENDED LUBRICANT . . . . . . . . . . 2-9 JET DRIVE IMPELLER . . . . . . . . . . . . . . . . . 2-24 CLEARANCE . . . . . . . . . .. . . . . .. . .. . . . 2-24 INSPECTION . . . . . . . . . . . . . . . . . . . . . . . 2-24 LUBRICANTS . . . . . . . . . . . . . . . . . . . . . . . . 2-6 LUBRICATING THE MOTOR. . . . . . . . . . . . . 2-6 LUBRICATION 2-5 .. .. .. • • • • .. • • .. .. . . .. . GEARCASE (LOWER UNin OIL. . . . . . . . . 2-7 JET DRIVE BEARING. . . . . . 2ˇ9 . . . . . . . . . . • LUBRICANTS . . . . . . . . . . . . . . . . . . . . . . . 2ˇ6 LUBRICATING THE MOTOR. . . . . . . . . . . . 2-6 LUBRICATION INSIDE THE BOAT. ...... TUNE-UP . • • • . • • • . . • .. . . . . . . . . . . . . . . 2-30 COMPRESSION TESTING . . . . . . . . . . . . . 2-32 ELECTRICAL SYSTEM CHECKS . . . . . . . . 2-38 ELECTRONIC IGNITION SYSTEMS. . . . . . 2-38 FUEL SYSTEM CHECKS . . . . . . . . . . . . . . 2-39 IDLE SPEED ADJUSTMENT. . . . . . . . . . . . 2-43 INTRODUCTION TO TUNE-UPS. . . . . . . . . 2ˇ30 SPARK PLUG WIRES. . . . . . . . . . . . . . . . . 2-38 SPARK PLUGS. . . . .. . . . . . . .. . . .. . . . . 2-33 TUNE-UP SEQUENCE . . . • . . . . . . . . . . . . 2-31 TUNE-UP SEQUENCE . . . . . . . . . . . . . . . . . 2ˇ31 POWER TRIMfTILT RESERVOIR . . . . . . . . 2ˇ9 WINTERIZATION. . . . . . . . . . . . . . . . . . . . . . 2ˇ84LUBRICATION INSIDE THE BOAT . . . . . . . . 2-7 MAINTENANCE COVERAGE IN PREPPING FOR STORAGE . ..•.. . . . . . . 2-84 THIS MANUAL . . . . . .. . . . . . . . . . . . . . . . . 2-2 2-2 MAINTENANCE & TUNE-UP GENERAL INFORMATION (WHAT EVERYONE SHOULD KNOW ABOUT MAINTENANCE) At Seloc, we estimate that 75% of engine repair work can be directly or indirectly attributed to lack of proper care for the engine. This is especially true of care during the off-season period. There is no way on this green earth for a mechanical engine, particularly an outboard motor, to be left sitting idle for an extended period of time, say for six months, and then be ready for instant satisfactory service. Imagine, if you will, leaving your car or truck for six months, and then expecting to turn the key, having it roar to life, and being able to drive off in the same manner as a daily occurrence. Therefore it is critical for an outboard engine to either be run (at least once a month), preferably, in the water and properly maintained between uses or for it to be specifically prepared for storage and serviced again immediately before the start of the season. Only through a regular maintenance program can the owner expect to receive long life and satisfactory performance at minimum cost. Many times, if an outboard is not performing properly, the owner will "nurse" it through the season with good intentions of working on the unit once it is no longer being used. As with many New Year's resolutions, the good intentions are not completed and the outboard may lie for many months before the work is begun or the unit is taken to the marine shop for repair. Imagine, if you will, the cause of the problem being a blown head gasket. And let us assume water has found its way into a cylinder. This water, allowed to remain over a long period of time, will do considerably more damage than it would have if the unit had been disassembled and the repair work performed immediately. Therefore, if an outboard is not functioning property, do not stow it away with promises to get at it when you get time, because the work and expense will only get worse the longer corrective action is postponed. In the example of the blown head gasket, a relatively simple and inexpensive repair job could very well develop into major overhaul and rebuild work. Maintenance Equals Safety OK, perhaps no one thing that we do as boaters will protect us from risks involved with enjoying the wind and the water on a powerboat. But, each time we perform maintenance on our boat or motor, we increase the likelihood that we will find a potential hazard before it becomes a problem. Each time we inspect our boat and motor, we decrease the possibility that it could leave us stranded on the water. In this way, performing boat and engine service is one of the most important ways that we, as boaters, can help protect ourselves, our boats, and the friends and family that we bring aboard. Outboards On Sail Boats Owners of sailboats pride themselves in their ability to use the wind to clear a harbor or for movement from Port A to Port B, or maybe just for a day sail on a lake. For some, the outboard is carried only as a last resortˇ in case the wind fails completely, or in an emergency situation or for ease of docking. Therefore, in some cases, the outboard is stowed below, usually in a very poorly ventilated area, and subjected to moisture and stale air • in short, an excellent environment for "sweating• and corrosion. If the owner could just take the time at least once every month, to pull out the outboard, clean it up, and give it a short run, not only would he/she have "peace of mind" knowing it will start in an emergency, but also maintenance costs will be drastically reduced. Maintenance Coverage In This Manual At Seloc, we strongly feel that every boat owner should pay close attention lo this section. We also know that it is one of the most frequently used portions of our manuals. The material in this section is divided into sections to help simplify the process of maintenance. Be sure to read and thoroughly understand the various tasks that are necessary to keep your outboard in tip-top shape. Topicsˇ covered in this section include: • General Information (What Everyone Should Know About Maintenance) ˇ an introduction to the benef..s and need for proper maintenance. A guide to tasks that should be performed before and after each use. • Lubrication Service • after the basic inspections that you should perform each time the motor is used, the most frequent form of periodic maintenance you will conduct will be the Lubrication Service. This section takes you through each of the various steps you must take to keep corrosion from slowly destroying your motor before your very eyes. • Engine Maintenance ˇ the various procedures that must be performed on a regular basis in order to keep the motor and all of its various systems operating properly. • BoatMaintenance ˇ the various procedures that must be performed on a regular basis in order to keep the boat hull and its accessories looking and working like new. • Tune-Upˇ also known as the pre-season tune-up, but don't let the name fool you. A complete tune-up is the best way to determine the cond..ion of your outboard while also preparing it for hours and hours of hopefully trouble-free enjoyment. And if you use your boat enough during a single season, a second or even third tune-up could be required. • Winter Storage and Spring Commissioning Checklists • use these sections to guide you through the various parts of boat and motor maintenance that protect your valued boat through periods of storage and return it to operating condition when it is time to use it again. • Specification Charts • located at the end of the section are quickˇ reference, easy to read charts that provide you with critical information such as General Engine Specifications, Maintenance Intervals, Lubrication Service (intervals and lubricant types) and Capacities. Engine Identification + See Figures 1 thru 5 From 1997 to 2003 Yamaha produced an extremely large number of models with regards to horsepower ratings, as well a large number of trim and option variances on each of those models. In this service guide, we've included all of the models, including the 1ˇ3 cylinder inline models, as well as V4 and V6 motors. We chose to do this because of the many similarities these motors have to each other. But, enough differences exist that many procedures will apply only to a sub-set of these motors. When this occurs, we'll either refer to the differences within a procedure or, if the differences are more significant, we'll break the motors out and give separate procedures. In order to prevent confusion, we try to sort and name the models in a way that is most easily understood. Fig. 1 A modeiiD tag, and often a date of manufacture tag, is found on the port ... MAINTENANCE & TUNE-UP 2ˇ3 In many cases, it is simply not enough to refer to a motor as a 25 hp model, sinoe in these years Yamaha produced as many as 4 different motors with that rating (the 395cc 2-cylinder, the 430cc 2-cylinder, the 496cc 2ˇ cylinder AND the 496oc 3-cylinder). This makes proper engine identification important for everything from ordering parts to even just using the procedures in this manual. Throughout this manual we will make reference to motors the easiest way possible. In some cases procedures may apply to all motors, in other cases, they may apply to alit-cylinder or all2-cylinder motors (or all 3-cylinder motors, or perhaps all V6 motors, as applicable). When it is necessary to distinguish between different types of motors with the same number of cylinders, we'll differentiate using the Hp rating or, since different motors may have the same rating, we'll use the Hp rating plus the size (and in the case of the 496cc 25hp motor, the number of cylinders). In most cases, mechanical procedures will be similar or the same across different Hp ratings of the same engine family (of the same size). So it won't be uncommon to see a title or a procedure refer to 9.9/15 hp (246cc) motors or 105Jˇ225 hp (2596cc) motors. In both cases, we would be referring to all the motors of a particular family, including all B (Inshore), C, P (Pro), S (Saltwater) or V (VˇMax) motors or other special models. Starting in 1997 Yamaha began using fuel injection systems on some of their larger outboards. By 2003 there are three possible systems (2 of which) we cover in this repair guide. Two of them are known as Electronic Fuel Injection (EFI) systems. The EFI (OX66) system was the first marine fuel injection system introduced by Yamaha. It is a multi-port manifold injected system which uses an automotive style oxygen sensor to continually adjust the air/fuel mixture (unique in the marine industry). Yamaha 4ˇstroke engines (covered elsewhere) also utilize an EFI system which is a multiˇport manifold injected system, however it does not use oxygen sensor feedback. The third style of injection (used only on the largest of motors) is the High Pressure Direct Injection (HPDI) which, as the name suggests, uses extreme high pressure air charges to inject fuel directly into the combustion chamber. Throughout this repair guide we may refer to both of the systems as a group, calling them simply Fuel Injected Motors, or we may specify EFI, meaning all but HPDI, EFI (OX66) meaning the EFI or HPDI. To help with proper engine identification, all of the engines covered by this manual are listed in the General Engine and General Engine System Specifications charts at the end of this section. In these charts, the engines are listed with their respective engine families, by horsepower rating, number of cylinders, engine type (inline or V), years of production and displacement (cubic inches and cubic centimeters or CCs). But, whether you are trying to tell which version of a particular horsepower rated motor you have in order to follow the correct procedure or are trying to order replacement parts, the absolute best method is to start by referring to the engine serial number lag. For all models covered here this ID tag (in the accompanying figure) is located on the side of the engine clamp or swivel/till brackets (port or starboard side depending upon the year and model). Most models are also equipped with a date of manufacture tag (located on the opposite side of the clamp or swiveVtilt bracket). Lastly, most models are also equipped with an Emissions Control Information label as well. ENGINE MODEL & SERIAL NUMBERS + 5ee Figures 1 thru 5 The engine model numbers are the manufacturer's key to engine changes. These alpha-numeric codes identify the year of manufacture, the horsepower rating, gearcase shaft length and various modeVoption differences (such as Saltwater, Pro-Series or V-max and starting/trim tilt options such as manual start/manual tilt or electric start power trim/lilt}. If any correspondence or parts are required, the engine model number must be used for proper identification. Remember that the model number establishes the model year for which the engine was produced, which is often not the year in which the motor was first installed on a boat. Also, keep in mind that a dale of manufacture may be the year prior to the designated model year. The engine model number tag also contains information used by the manufacturer internally as an engine family designation and a serial number (a unique sequential identifier given ONLY to that one motor). When present, the emissions control information label states that the motor is in compliance with EPA emissions regulations for the model year of that engine. And, more importantly, it gives tune-up specifications thai are vital to proper engine performance (that minimize harmful emissions). The specifications on this label may reflect changes that are made during Fig. 2 •••and/or starboard side of most engine clamp or swivel/tilt brackets production runs and are often not later reflected in a company's service Fig. 3 The modeiiD tag provides critical Information to identify and service the engine (4-stroke shown, but 2-stroke tags are mounted In the same way) Fig. 4 Keep in mind that the date of manufacture is often the year BEFORE the model year Fig. 5 When present, the emission control information label supercedes specifications listed elsewhere Mode l Prop Shaft T rimiTilt Shaft Method Model CodeHP Method of Control Year Variant oses, it would obviously be more exact to add the Fig. 43 For portable tanks, either add the oil and gasoline at the same time, or add the oil first, then add the gasoline to ensure proper mixing gasoline first, then add a suitable amount of oil to match it. The problem with adding gasoline first is that unless the tank could be thoroughly agitated afterward {and that would be really difficult on bui..ˇin tanks), the oil might not mix properly with the gasoline. Don't take that unnecessary risk. To determine the proper amount of oil to add to achieve the desired fuel:oil ratio, refer to the Fuei:Oil Ratio chart at the end of this section. Oil Injection + See Figures 44, 45 and 46 The Yamaha Precision Blend oil injection system utilizes a mechanically driven oil pump mounted to the powerhead that is connected to the throttle by way of a linkage arm. The system is powered by the crankshaft. which drives a gear in the pump, creating oil pressure. As the throttle lever is advanced to increase engine speed, the linkage arm also moves, opening a valve that allows more oil to flow into the oil pump. Most mechanical-injection systems incorporate some form of a low-oil warning alarm that is also connected to an engine-overheating sensor. Some versions of the system might include a built-in speed limiter. This sub-system is designed to reduce engine speed automatically when oil problems occur. This important feature goes a long way toward preventing severe engine damage in the event of an oil injection problem. The procedure for filling these systems is simple. Most Yamaha motors utilize a powerhead mounted oil reservoir. Many V6 motors are also equipped with a remote, boat mounted, oil tank (a larger tank designed to hold more oil than a powerhead mounted unit}. In either case, the main reservoir tank contains a filler cap that is removed in order to add oil to the tank. Be sure to check the oil level EVERY time the motor is operated. Whenever oil is added, place a piece of tape on the tank to mark the level and watch how fast it drops in relation to engine usage (hours and fuel consumption). Watch for changes in usage patterns that could indicate under or over oiling. Especially with a system that suddenly begins to deliver less oil, you could save yourself significant engine damage by discovering a problem that could have starved the motor for lubrication. Should the oil hose become disconnected or suffer a break/leak, the oil prime might be lost. If so, the system should be primed before priming the fuel system and starting the engine. More details on servicing the oiling system are found in the Lubrication section of this manual. • It is highly advisable to carry a few spare bottles of 2-stroke oil with you onboard. Even in the event of an oil system failure, oil can be added to a fuel tank (in the proper ratio) in order to limp the boat and motor safely home. . CHECKING FOR WATER OR CONTAMINANTS + See Figure 47 To protect the powerhead from potential damage should contaminants enter the oil system (instead of oil), you should ALWAYS perform a quick check of the oil tank before every outing. Powerhead mounted oil tanks are normally equipped with a water and contaminant trap (either a short length of dead-end hose on the bottom of the tank or a trap/drain hose that is run upward attaching to the filler neck). II water or contaminants are found, they must be removed in order to protect the motor. If large amounts are present, the tank should be drained and thoroughly cleaned. Also, if large amounts of water or contaminants are present, you'd do well to discover the source. What gremlin is sneaking onto your boat at night, opening the cap and putting them there? Fuel Filter + See Figure 48 A fuel filter is designed to keep particles of dirt and debris from entering the carburetor(s) or fuel injectors clogging the tiny internal passages. A small speck of dirt or sand can drastically affect the ability of the fuel system to deliver the proper amount of air and fuel to the engine. II a filter becomes clogged, it will quickly impede the flow of gasoline. This could cause lean fuel mixtures, hesitation and stumbling and idle problems in carburetors. Although a clogged fuel passage in a fuel injected engine could also cause lean symptoms and idle problems, dirt can also prevent a fuel injector from MAINTENANCE & TUNE-UP 2-15 closing properly. A fuel injector that is stuck partially open by debris will cause the engine to run rich due to the unregulated fuel constantly spraying from the pressurized injector. Regular cleaning or replacement of the fuel filter (depending on the type or types used) will decrease the risk of blocking the flow of fuel to the engine, which could leave you stranded on the water. It will also decrease the risk of damage to the small passages of a carburetor or fuel injector that could require more extensive .and expensive replacement. Keep in mind that fuel filters are usually inexpensive and replacement is a simple task. Service your fuel filter on a regular basis to avoid fuel delivery problems. We tried to find a pattern to tell us what type of filter will be installed on a powerhead, based on the year or model of the engine. However, Yamaha does not seem to have a whole lot of rhyme or reason when it comes to choosing a fuel filter for their outboards (or if they did, we couldn't figure it out). Loosely, we'll say that most smaller Yamaha outboards use disposable, inline filters {or fuel tank strainers on the smallest of outboards), while larger motors tend to use a serviceable filter element that can be removed from a housing/cup assembly for cleaning or replacement. However there are exceptions to this and some larger motors may be equipped with a nonˇ serviceable inline filter. The HPDI motors are normally equipped with both a serviceable filter (located inline before the mechanical fuel-pump) and a nonserviceable filter (located inline before the vapor separator assembly). Also, keep in mind that the type of fuel filter used on your boavengine will vary not only with the year and model, but also with the accessories and rigging. Because of the number of possible variations it is impossible to accurately give instructions based on model. Instead, we will provide instructions for the different types of filters the manufacturer used on various families of motors or systems with which they are equipped. To determine what filter(s) are utilized by your boat and motor rigging, trace the fuel line Fig.44 Most Yamaha motors use a powerhead mounted oil reservoir •.. Fig. 45 . . . but many V6 motors utilize a boat mounted remote oil tank Fig.47 Check the oil reservoir trap for water or contaminants before EVERY outing Fig. 48 Boats with integrated fuel tanks will usually be rigged with an automotive style spin-on fuel filter/water separator 2-1 6 MAINTENANCE & TUNE-UP from the tank to the fuel pump and then from the pump to the carburetor(s) or EFVHPDI fuel vapor separator tank. Most Yamaha outboards utilize a serviceable filter element that is placed inside a cap and housing found inline just before the fuel pump. However, some models may instead (or ALSO in the case of HPDI models) be equipped with a non-serviceable inline filter in a disposable housing which is replaced by simply removing the clamps, disconnecting the hoses and installing a new filter. When installing a new disposable inline filter, make sure the arrow on the filter points in the direction of fuel flow. ˇ Some motors have a fuel filter mounted in the fuel tank itself. On small motors with integral fuel tanks (such as the 2-5 hp motors) the only fuel filter element is normally mounted on the fuel petcock or the fuel outlet fitting which must be removed from the tank in order to service it. For larger motors, in addition to the fuel fiHer mounted on the engine, a filter is usually found inside or near the fuel tank. Because of the large variety of differences in both portable and fixed fuel tanks, it is impossible to give a detailed procedure for removal and installation. However, keep in mind that most inˇ tank filters are simply a screen on the pickup line inside the fuel tank. Filters of this type rarely require service or attention, but if the tank is removed for cleaning the filter will usually only need to be cleaned and returned to service (assuming they are not tom or otherwise damaged). • Most EFI/HPDI motors are equipped with additional fuel filter elements either on the high-pressure electric fuel pump or the pressure regulator. However these elements are not maintenance items and should only need attention during repair or replacement of these components. Depending upon the boat rigging a fuel filter/Water separator may be found inline between a boat mounted fuel tank and the motor. Boat mounted fuel filter/water separators are normally of the spin-on filter type (resembling automotive oil filters) but will vary greatly with boat rigging. Replacement of filters/separators is the same as a typical automotive oil filter replacement, just make sure to have a small drain basin handy to catch escaping fuel and make sure to coat the rubber gasket with a small dab of engine oil during installation. FUEL FILTER SERVICE system, always work in a well-ventilated area. Do not allow spray or vapors to come in contact with a spark or open flame. Do not smoke while working around gasoline. Keep a dry chemical fire extinguisher near the work area. Always keep fuel in a container specifically designed for fuel storage; also, always properly seal fuel containers to avoid the possibility of fire or explosion. Integral Fuel Tank Models A small serviceable filter element is usually found on the fuel petcock or fuel tank outlet fitting on integral tank models. This should include the 2ˇ5 hp motors. To inspect, clean and/or replace this filter element, proceed as follows: 1. Drain the fuel in the tank into a suitable container. 2. It is usually necessary or just plain easier to work on with the fuel tank removed from the powerhead. Remove the mounting bolts and reposition the tank as necessary to disconnect a fuel line. In some cases it is easier to leave the fuel line connected to the tank and instead disconnect it from the other (carburetor) end. 3. Loosen the fuel petcock or fuel outlet fitting clamp screw or nut. 4. Remove the petcock from the clamp and tank. 5. Clean the filter assembly in solvent and blow it dry with compressed air. If excessively dirty or contaminated with water, replace the filter. 6. Install the petcock on the clamp and tank then connect the hose. 7. Tighten the fuel petcock clamp screw or nut. 8. Reposition the fuel tank and secure using the mounting bolts. 9. Check the fuel filter installation for leakage. Disposable lnline Filters As noted eartier, some Yamaha outboards are be equipped with a disposable inline filter. Generally speaking a few of the motors (including the 618 hp and some of the fuel injected motors, specifically most HPDI models) are equipped with a disposable, inline filter. For all carbureted models, the filter is found inline just before the mechanical fuel pump. For HPDI model the non-serviceable fiHer is normally found inline just before the vapor separator tank. This type of filter is a sealed canister type (usually plastic) and cannot be cleaned, so service is normally limited to replacement. Because of the relative ease and relatively low expense of a filter (when compared with the time and hassle of a carburetor overhaul) we encourage you to replace the filter at least annually. On HPDI models this filter is a second line of defense, as fuel must pass through a serviceable filter prior to reaching the vapor separator filter, therefore annual replacement may not be necessary, if you've kept up with maintaining the primary filter. Before servicing the high or medium pressure fuel circuits of the HPDI system, please refer to the information on Releasing Fuel System Pressure in the High Pressure Direct Injection System section. Failure to release system pressure before disconnecting fuel lines or fittings could result in extremely dangerous pressurized fuel spray which would create a significant danger of fire or explosion, as well as danger of injury from the spray itself. When replacing the filter, release the hose clamps (on carbureted models they are usually equipped with spring-type clamps that are released by squeezing the tabs using a pair of pliers) and slide them back on the hose, past the raised portion of the filter inlet/outlet nipples. On HPDI models the clamps are usually crimped into position and must be carefully cut to release them (and obviously, replaced with new crimp style clamps once the filler is installed again). Once a clamp is released, position a small drain pan or a shop towel under the filter and carefully pull the hose from the nipple. Allow any fuel remaining in the filter and fuel line to drain into the drain pan or catch fuel with the shop towel. Repeat on the other side, noting which fuel line connects to which portion of the filter (lor assembly purposes). lnline fillers are usually marked with an arrow indicating fuel flow. The arrow should point towards the fuel line that runs to the motor (not the fuel tank). Before installation of the new filter, make sure the hoses are in good condition and not brittle, cracking and otherwise in need of replacement. During installation, be sure to fully seat the hoses, then place the clamps over the raised portions of the nipples to secure them. Spring clamps will weaken over time, so replace them if they've lost their tension. If wire ties or adjustable clamps were used, be careful not to overtighten the clamp. If the clamp cuts into the hose, it's too tight; loosen the clamp or cut the wire tie (as applicable) and start again. 7.* CAUTION Before returning the outboard to service, use the primer bulb to pressurize the system and check the filter/fittings for leaks. On HPDI motors, refer to the section on High Pressure Direct Injection to determine how to property pressurize the system and check for leaks. Serviceable Canister-Type lnline Filters + See Figure 50 lfs probably safe to say that most Yamaha motors (except for the smallest of the motors) are equipped with a serviceable canister-type inline filter. These can be identified by their design and shape, which varies from the typical inline filter. A typical, disposable inline filter will have a simple round canister to which the fuel lines attach at either end. The serviceable inline filters used by Yamaha usually have 2 fuel inlets at the top of the filter housing and the serviceable element is located in a bowl or cap that is threaded up from underneath the housing. When servicing these filters it may be possible to access and unthread the bowl without disconnecting any hoses, but if so, you'll have to hold the housing steady to prevent stressing and damaging the fuel lines. However, on some motors access to the bowl is impossible without first disconnecting one or more fuel hoses and repositioning the assembly. .. .. Element -.. ..-Element 0-Ring -0 0-0-RingŽBowl -8 t]}-Bowl MAINTENANCE & TUNE-UP 2-17 Fig. 50 Exploded view of a common serviceable Yamaha canister-type fuel filter Fig. 51 Typical Yamaha serviceable canistertype filter assembly Fig. 52 Access the element by unthreading the bowl from the housing Serviceable filter elements should be cleaned carefully using solvent and inspected for clogging, tears or damage. If problems are found, normally just the element itself will require replacement. You really should always replace the 0-ring, its cheap insurance, but you CAN reuse it in a pinch, as long as it is not tom, cut or deformed. While you're servicing the filter always inspect and replace any damaged hose or clamp as you would with any other fuel filter. lnline Engines • See Figures 50, 51 and 52 • It is usually possible to service the filter element without removing thecanister from the motor, however if access is light, follow the steps for removing the hose(s) from the assembly so It can be repositioned. Although most filter assemblies are pretty straight forward, containing a filter element and a single Oˇring seal, some models may differ containing additional components such as a water indicator float, a spring, or additional seals. Keep track of the components as they are removed to ensure you will know how to properly assemble them. 1. If necessary for better access, remove the assembly from the powerhead as follows: a. On models with metal clips, slide each hose retaining clip off the filter assembly cover nipples wijh a pair of pliers. Disconnect the hoses from the cover and plug the hoses to prevent fuel leakage. b. On models with plastic clips, unsnap the plastic clips holding the hoses to the fmer assembly cover. Disconnect the hoses from the cover and plug the hoses with golf tees to prevent fuel leakage. c. Remove the nut securing the filter cover to its mounting bracket. Remove the cover and canister assembly. 2. Unscrew the canister from the filter assembly cover. Remove the filter element from the canister. 3. Drain the canister and wipe the inside dry with a clean lint-free cloth or paper towel. 4. Inspect the cover 0-ring. If necessary, remove and discard the old 0ˇ ring or gasket, as required. To Install: 5. Clean the filter screen with solvent to remove any particles. If the filler screen is clogged or damaged, replace it. 6. Install the undamaged 0-ring, or a new 0-ring seal/gasket to the filter canister, as required. 7. Install the filter and the filter canister. Tighten the canister securely. 8. If the filter housing assembly was repositioned for access, install it as follows: a. Connect the inlet and outlet hoses to the canister cover. b. Install the nut securing the filter cover to its mounting bracket and tighten securely. c. On models wijh metal clips, slide each hose retaining clip onto the filter assembly cover nipples with a pair of pliers. d. On models with plastic clips, snap the plastic clips holding the hoses to the filter assembly cover. 9. Check the fuel filter installation for leakage by priming the fuel system with the fuel line primer bulb. V4 and V6Engines + See Figures 53 and 54 Although most filter assemblies are pretty straight for.vard, containing a filter element and a single Oˇring seal, some models may differ containing additional components such as a water indicator float, a spring, or additional seals. Keep track of the components as they are removed to ensure you will know how to properly assemble them. The filter assembly found on V4 and V6 motors is very similar to the serviceable filter used on many inline engines, however the major difference Fig. 53 Typical canister-type filter used on the V4 and V6 motors . @ .. .. 0 -Bowl Ic:::>, <::> 0-ringˇ =..0-rlngElement ....-t.ookrln}--__j Spring f LockringCollar Ž Retaining .lip3"1 I FilterBracket Fig. 54 Exploded view of a canister-type filter equipped with lockring and lock-ring retaining clip 2-18 MAINTENANCE & TUNE-UP comes in the use of a lock-ring to secure the filter bowl. In addition some model.. (including most or all EFI/HPDI models) utilize a lock-ring retaining clip whtch bolts to the top of the housing to prevent the lock-ring from possibly loosening in service. . 1. On EFVHPDI motors, or models equipped with a lock-ring retaining clip, loosen the bolt and remove the retaining clip so the lock-ring can be loosened. 2. If equipped, unplug the bowl sensor harness connector. 3. Unscrew the ring nut securing the canister to the Iiiier assembly cover. 4. Unscrew the canister from the filter assembly cover. 5. Remove the filter element and spring from the canister (along with any other components, such as a water indicator float). 6. Drain the canister and wipe the inside dry with a clean lint-free cloth or paper towel. 7. Inspect the cover 0-ring. If necessary, remove and discard the old Gring or gasket, as required. To Install: 8. ..lean the filter screen with solvent to remove any particles. If the filter screen IS clogged or damaged, replace it. 9. Install the undamaged 0-ring, or a new 0-ring seal/gasket to the filter canister, as required. tO. Install the spring and filter into the filter canister (along with any other components as noted during removal). 11. Install the canister assembly onto the filter assembly cover and screw on the ring nut. Tighten the ring nut securely. 12. If equipped, connect the bowl wiring harness. 3: On EFI/HPDI motors or models so equipped, install the lock-ring clip and secure using the fastener. 14. Check the fuel filter installation for leakage by priming the fuel system with the fuel line primer bulb. Propeller + See Figures 55, 56 and 57 As you know, the propeller is actually what moves the boat through the water. The propeller operates in water in much the same manner as a wood ..crew or auger passing through wood. The propeller "bitesˇ into the water as 11 rotates. between the blades and out to the rear in the shape ol a cone. Thts through the water is what propels the boat All Yamaha outboards are equipped, from the factory with a through-thepropeller exhaust, meaning that exhaust gas is routed o..t through the propeller. GENERAL PROPELLER INFORMATION Diameter and Pitch + See Figures 58 and 59 Only two dimensions of the propeller are of real interest to the boat owner: diameter and pitch. These two dimensions are stamped on the propeller hub and always appear in the same order, the diameter first and then the ..itch .. Propellers furnished with the outboard by Yamaha have a letter destgnatton following the pitch size. This letter indicates the propeller type. For instance,.th.. numbers and letter ..-7/8 x 10-1/2 -F stamped on the back of one blade tndtcates the propeller dtameter to be 9ˇ 7/8 in., with a pitch of 10-1/2 in., and it is a Type F. The diameter is the measured distance from the tip ol one blade to the tip of the other. 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 9-7/8 in. x 10-1/2 in., the propeller should travel 1 0-1/2 tnches through the water each time it revolves. If the action was perfect and there was no slippage, then the pitch by the propeller rpm would be the boat speed. ..ost o..tboard manuf..cturers equi.. their units with a standard propeller, havtng a dtameter and p1tch they constder to be best suited to the engine and 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 o,f the propell..r determines it.s load-carrying capacity. A two-blade propeller IS used for high-speed runmng under very light loads. A lour-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 htgh performance umts and load carrying workhorses. Propeller Selection . There is n? one propelle.. that will do the proper job in all cases. The list of stzes and wetghts of boats •s almost endless. This fact, coupled with the many boat-engine combinations, makes the propeller selection for a specific purpose a difficult task. Actually, in many cases the propeller may be 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 that the charts are based on average boats 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. ..ropellers are available with a wide range of pitch. Remember, a low pitch des1gn ta.kes a smaller bite of water than a high pitch propeller. This means the low p1tch propeller will travel less distance through the water per Fig. 55 Most Yamaha propellers are secured using a washer, castle nut and cotter pin Fig. 56 An installed view of a nut retained propeller Fig. 57 A severely damaged propeller (it's dead Jim) Fig.58 Diameter and pitch are the two basic dimensions of a propeller. Diameter is measured across the circumference of a circle scribed by the propeller blades. revolution. However, the low pitch will require less horsepower and will allow the engine to run faster. All engine manufacturers design their units to operate with full throttle at or in the upper end of the specified operating rpm. If the powerhead is ' operated at the rated rpm, several positive advantages will be gained. • Spark plug life will be increased. • Better fuel economy will be realized. • Steering effort is often reduced. • The boat and power unit will provide best performance. Therefore, take t1me to make the proper propeller selection for the rated rpm of the engine at full throttle with what might be considered an average load. The boat w111 then be correctly balanced between engine and propeller throughout the entire speed range. A reliable tachometer must be used to measure powerhead speed at full throttle, to ensure that the engine achieves full horsepower and operates efficiently and safely. To test for the correct propeller, make a test run in a bodx of smooth water with the lower unit in forward gear at full throttle. If the read1ng IS above the operating range, try propellers of greater one IS found allowing the powerhead to operate continually w..hin the recommended full throttle range. If the engine is unable to deliver top performance and the powerhead 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 yery cold water. It will also lose rpm wh ' en run in salt water, as compared w1th fresh water. A hot, low-barometer day will also cause the engine to lose power. Fig. 59 This diagram illustrates the pitch dimension of a propeller. The pitch is the theoretical distance a propeller would travel through water if there were no friction MAINTENANCE & TUNE-UP 2-19 Cavitation • See Figure 60 Cavitation is the forming of voids in the water just ahead of the propeller blades. Marine propulsion designers are constantly fighting the battleagainst the formation of these voids, due to excessive blade tip speed and engine wear . . The voids may ..e ..lied with air or water vapor, or they may actually be a p..rt1at vacuum. Cav1tat1on may be caused by installinga piece of equ1pment too close to the lower unit, such as the knot indicator pickup, depth sounder or bait tank pickup. Vibration The propeller should be checked regula..y to ensure that all blades are in good condition. If any of the blades become bent or nicked, this condition will set up vibra..ions in the drive unit and motor. If the vibration becomes very senous, 11 Will cause a toss of power, eff1ciency, and boat performance. If the vibration is allowed to continue over a period of time, rt can have a damaging effect on many oftheoperating 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 mamtenance and lubrication. Vibration can also be reduced in some cases by increasing the number of blades. For this reason, many racers use twoˇ blade propellers, while luxury cruisers have four-and five-blade propellers installed. Shock Absorbers • See Figure 61 The . shock absorber in the propeller plays a very important role in protectingthe 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 shock absorber 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 traln. If the poY:'er train was to absorb an impact great enough to stop rotation, even for an Instant, something would have to give, resulting in severe damage. If a propeller is subjected to repeated striking of underwater objects, it will eventually slip on its clutch hub under normal loads. If the propeller should start to slip, a new shock absorber/cushion hub will have to be installed by a propeller repair shop. Propeller Rake • See Figure 62 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 the propeller is said to have a zero degree (0°.) rake. As the blade slant.. back the rake increases. Standard propellers have a rake angle from o• to 15°. ' A higher rake angle generally improves propeller performance in a cavi . tating or ventilating situation. On lighter, faster boats, a higher rake often W11l 1ncrease performance by holding the bow of the boat higher. Progressive Pitch • See Figure 63 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 1ncreases to the trailing edge. 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. 2-20 MAINTENANCE & TUNE-UP Fig. 60 Cavitation (air bubbles) can damage Fig. 61 A damaged rubber hub could cause the propeller to slip a prop Fig. 63 Comparison of a constant and progressive pitch propeller. Notice how the pitch of the progressive propeller (right) changes to give the blade more thrust Cupping + See Figure 64 ˇ. ˇ . II the propeller is cast with an edge curl inward on the trailing edge, the bladeis 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 cavitating or ventilating situation. Acup has the effect of adding to the propeller pitch. Cupping usually will reducefull-throttle engine speed about 150 to 300 rpm below that of the engine equipped with the same pitch propeller without a cup to the blade. A propeller repair shop is able to increase or decrease the cup on the blades. This change, as explained, will aner powerhead rpm to meet specific operating demands. Cups are rapidly becoming standard on propellers. In order lor a cup to be the most effective, the cup should be completely concave (hollowed) and finished with a sharp comer. II the cup has any convex rounding, the effeC1iveness ofthe cup will be reduced. Rotation + See Figure 65 Propellers are manufactured as right-hand (RH) rotation or left-hand (LH) rotation. The standard propeller for outboard units is RH rotation. A right-hand propeller can easily be identified by observing it. Observe how the blade of the right-hand propeller slants from the lower left to upper right. The left-hand propeller slants in the opposite direction, from lower right to upper left. When the RH propeller is observed rotating from astern the boat, it will be rotating clockwise when the outboard unit is in forward gear. The left-hand propeller will rotate counterclockwise. Fig. 62 A higher rake angle generally Improves propeller performance Fig. 64 Propeller with a cupped leading edge. Cupping gives the propeller a better hold in the water High Performance Propellers + See Figures 66 and 67 The term highperformance is usually associated with, orhas the connotation of, something used only tor racing. The Yamaha high performance propeller doesnot fit this category and is not considered an aftermarket item. The Yamahahigh performance propeller is made of stainless steel with sophisticated designed blades, and carries an embossed P for positive identification. Theaccompanying illustration of a high performance propeller clearly shows the unique design of the long blades and other features. This propeller is the weed less type, having extra sharp blades. Installation of a high performance propeller requires raising the transom height, trim out after planing, and installation of a special design trim tab. Installation of a water pressure gauge is highly recommended, because raising the transom height will affect the amount of water entering the lower unit through the intake holes. An inadequate amount of water taken in will certainly cause powerhead cooling problems. The high performance propeller has standard attaching hardware with the exception of the inner spacer, which is a special three-pronged design. INSPECTION + See Figures 68, 69 and 70 The propeller should be inspected before and after each use to be sure the blades are in good condition. If any of the blades become bent or nicked, this condition will set up vibrations in the motor. Remove and inspect the propeller. Use a file to trim nicks and burrs. Take care not to remove any more material than is absolutely necessary. *-* CAUTION Never run the engine with serious propeller damage, as it can allow for excessive engine speed andfor vibration that can damage the motor. Also, a damaged propeller will cause a reduction in boat performance and handling. Also, check the rubber and splines inside the propeller hub for damage. If there is damage to either of these, take the propeller to your local marine dealer or a •prop shopˇ. They can evaluate the damaged propeller and determine ii it can be saved by re-hubbing. Additionally, the propeller should be removed AT LEAST every 100 hours of operation or at the end of each season, whichever comes first for cleaning, greasing and inspection. Whenever the propeller is removed, apply a fresh coating of Yamaha All-Purpose Marine Grease or an equivalent water-resistant grease to the propeller shaft and the inner diameter of the propeller hub. This is necessary to prevent possible propellerseizure onto the shaft that could lead to costly or troublesome repairs. Also, whenever the propeller is removed, any material entangled behind the propeller should be removed before any damage to the shaft and seals can occur. This may seem like a waste of time at first, but the small amount of time involved in removing the propeller is returned many times by reduced maintenance and repair, including the replacement of expensive parts. MAINTENANCE & TUNE-UP 2-21 • Propeller shaft greasing and debris inspection should occur more often depending upon motor usage. Frequent use in salt, brackish or polluted waters would make it advisable to perform greasing more often. Similarly, frequent use in areas with heavy marine vegetation, debris or potential fishing line would necessitate more frequent removal of the propeller to ensure the gearcase seals are not in danger of becoming cut. REMOVAL & INSTALLATION The propeller is secured to the gearcase propshaft either by a drive pin on only the smallest of the smallest portable motors, or by a castellated hex nut on all other Yamahas. It is pretty easy totell the difference, just take a look at the propeller, if you see a nut, that's how it is secured. If however, you're working on a 2 hp motor, you should see a cotter pin going through the nose cone of the propeller itself, telling you that it is a shear pin prop. For models secured by a hex nut, the propeller is driven by a spllned connection to the shaft and the rubber drive hub found inside the propeller. The rubber hub provides a cushioning that allows softer shifts, but more importantly, it provides some measure of protection for the gearcase components in the event of an impact. On 2 hp motors, where the propeller is retained by a drive pin, impact protection is provided by the drive pin itself. The pin is designed to break or shear when a specific amount of force is applied because the propeller hits something. In both cases (rubber hubs or shear pins) the amount of force necessary to break the hub or shear the pin is supposed to be just less than the amount of force necessary to cause gearcase component damage. In this way, the hope is that the propeller and hub or shear pin will be sacrificed in the event of a collision, but the more expensive gearcase components will survive unharmed. Although these systems do supply a measure of protection, this, unfortunately, is not always the case and gearcase component damage will still occur with the right impact or with a sufficient amount of force. Counter clockwise or Left hand /.. HIGH PERFORHANCE SPACER PROPELLER Clockwiseor Right hand Fig. 65 Note the blade angle is reversed on right and lett-hand propellers Fig. 68 This propeller is long overdue for repair or replacement Fig. 66 Exploded view of a high performance prop mounting (note 3-prong spacer) Fig. 69 Although minor damage can be dressed with a file ... Fig. 70 ... a propeller specialist should repair large nicks or damage 2ˇ22 MAINTENANCE & TUNE-UP ->iH. WARNING Do not use excessive force when removing the propeller from the hub as excessive force can result in damage to the propeller, shaft and, even other gearcase components. If the propeller cannot be removed by normal means, consider having a reputable marine shop remove it. The use of heat or impacts to free the propeller will likely lead to damage. • Clean and lubricate the propeller and shaft splines using a highquality, water-resistant, marine grease every time the propeller is removed from the shaft. This will help keep the hub from seizing to the shaft due to corrosion (which would require special tools to remove without damage to the shaft or gearcase.) Many outboards are equipped with aftermarket propellers. Because of this, the attaching hardware may differ slightly from what is shown. Contact a reputable propeller shop or marine dealership for parts and information on other brands of propellers. Shear Pin Props (2 Hp Motors) • See Figures 71 and 72 • On these models there is normally a small holder on the tiller handle that contains one or more extra drive pins and cotter pins. ALWAYS replace these pins when used on the water, that way you won't be stranded next time. The propeller on the smallest of the portable Yamaha outboards (2 hp) is secured to the propshaft using a drive pin. Be sure to always keep a spare drive pin handy when you are onboard the boat. Remember that a sheared drive pin will leave you stranded on the water. A damaged shear pin can also contribute to motor damage, exposing it to over-rewing while trying to produce thrust. The pin itself is usually locked in position by the propeller/cone that is in turn fastened by a cotter pin. ALWAYS replace the Fig. 71 Shear pin props are held in place using a cotter pin through the nose cone f--Cotter Pin Fig. 72 Exploded view shear pin propeller mounting cotter pin once it has been removed. Remember that should the cotter pin fail, you could be diving to recover your propeller. 1. Disconnect the spark plug lead from the plug for safety. *-'* CAUTION Don't ever take the risk of working around the propeller if the engine could accidentally be started. Always take precautions such as disconnecting the spark plug lead. 2. Cut the ends off the cotter pin using a pair of wire cutters (as that is easier than trying to straighten them in most cases) or straighten the ends using a pair of pliers (whichever you prefer). Next, free the pin by grabbing the head with a pair of needlenose pliers. Either tap on the pliers gently with a hammer to help free the pin from the propeller capor carefully use the pliers as a lever by carefully prying back against the propeller cone. Discard the cotter pin once it is removed. 3. Grasp and gently pull the propeller off the drive pin and the propeller shaft. 4. Grasp and remove the drive pin using the needle-nose pliers. • If the drive pin is difficult to remove, use a small punch or a new drive pin as a driver and gently tap the pin free from the shaft. To Install: 5. Clean the propeller hub and shaft splines, then apply a fresh coating of a water-resistant, marine grease. 6. Insert the drive pin into the propeller shaft. 7. Align the propeller, then carefully slide it over the shaft. 8. Install a new cotter pin and then spread the pin ends in order to form tension and secure them. 9. Reconnect the spark plug lead. Castellated Nut Props • See Figures73 thru81 On almost all Yamaha outboards the propeller is held in place over the shaft splines by a large castellated nut. The nut is so named because, when viewed from the side, it appears similar to the upper walls or tower of a castle. For safety, the nut is locked in place by a cotter pinthat keeps it from loosening while the motor is running. The pin passes through a hole inthe propeller shaft, as well as through the notches in the sides of the castellated nut. Install a new cotter pin anytime the propeller is removed and, perhaps more importantly, make surethe cotter pin is of the correct size and is made of materials designed for marine use. Whenever working around the propeller, check for the presence of black rubber material in the drive hub (don't confuse bits of black soottcarbon deposits from the exhaust as rubber hub material) and spline grease. Presence of this material normally indicates that the hub has turned inside the propeller bore (have the propeller checked by a propeller repair shop). Keep in mind that a spun hub will not allow proper torque transfer from the motor to the propeller and will allow the engine to over-rev in attempting to produce thrust. Ifthe propeller has spun on the hub it has been weakened and is more likely to fail completely in use. 1. For safety, disconnect the negative cable (if so equipped} and/or disconnect the spark plug leads from the plugs (ground the leads to prevent possible ignition damage should the motor be cranked at some point before the leads are reconnected to the spark plugs). ;;,->1<-CAUTION Don't ever take the risk of working around the propeller if the engine could accidentally be started. Always take precautions such as disconnecting the spark plug leads and, if equipped, the negative battery cable. 2. Cut the ends off the cotter pin using wire cutters (as that isusually easier thantrying to straighten them in most cases) or straighten the ends of the pin using a pair of pliers, whichever you prefer. Next, free the pinby grabbing the head with a pair of needle-nose pliers. Either tap on the pliers gently with a hammer to help free the pin from the nut or carefully use the pliers as a lever by prying back against the castellated nut. Discard the cotter pinonce it is removed. MAINTENANCE & TUNE-UP 2-23 3. Place a block of wood between the propeller and the anti-ventilation housing to lock the propeller and shaft from turning, then loosen and remove the castellated nut Note the orientation and then remove the washer and/or splined spacer from the propeller shaft. 4. Slide the propeller from the shaft. If the prop is stuck, use a block of wood to prevent damage and carefully drive the propeller from the shaft. • If the propeller is completely seized on the shaft, have a reputable marine or propeller shop freeit. Don't risk damage to the propeller or gearcase by applying excessive force. 5. Note the direction in which the thrust washer is facing (since some motors or aftermarket props may use a thrust washer equipped with a fishing line trap that must face the proper direction if it is to protect the gearcase seal). Remove the thrust washer from the propshaft (if the washer appears stuck, tap lightly to free it from the propeller shaft). 6. On Vmax models with Twin Rotating Props (TRP), bend any teeth from the toothed washer away from the inner (forward) propeller retaining nut). Next, use a box-end wrench or open-end socket and a breaker bar (along with the same block of wood to hold the prop) to loosen the forward propeller retaining nut. Remove the nut, toothed washer, forward propeller andforward thrust washer from the shaft (also noting the orientation, the bevel normally faces forward). 7. Clean the thrust washer(s), propeller and shaft splines of any old grease. Small amounts of corrosion canbe removed carefully using steel woolortine grit sandpaper. 8. Inspect the shaft for signs of damage Including twisted splines or excessively worn surfaces. Rotate the shaft while looking for any deflection. IN Fig.80 Theninstall the outer spacer, washer (if used), nut and cotter pin Fig. 81 Assembled and ready to go! 2-24 MAINTENANCE & TUNE-UP Replace the propeller shaft if these conditions are found. Inspect the thrust washer for signs of excessive wear or cracks and replace, if found. To Install: 9.Apply a fresh coating of Yamaha All-Purpose Marine Grease or an equivalent water-resistant grease to all surfaces of the propeller shaft and to the splines inside the propeller hub. 8 Some people prefer to use AntiˇSeize on the hub splines, which is acceptable in most applications, but if used you should double-check after the first 10ˇ20 hours of service to make sure the anti-seize is holding up to operating conditions. 1 o. On Vmax models with TRP, install the forward thrust washer (with the bevel facing forward as noted during removal), followed by the forward propeller, toothed washer and propeller nut. Tighten the nut to 47 ft. lbs. (65 Nm), then bend the teeth of the washer in position to secure the nut. 11. Position the thrust washer over the propshaft in the direction noted during removal. (Generally speaking, the flat shoulder should face rearward toward the propeller while the bevel faces forward toward the gearcase). 12. Carefully slide the propeller onto the propshaft, rotating the propeller to align the splines. Push the propeller forward until it seats against the thrust washer. 13. Install the splined and/or plain spacer onto the propeller shaft, as equipped. 14. Place a block of wood between the propeller and housing to hold the prop from turning, then thread the castellated nut onto the shaft with the cotter pin grooves facing outward. 15. Tighten the castellated nut to specification using a suitable torque wrench. Install a new cotter pin through the grooves in the nut that align with the hole in the propshaft. If the cotter pin hole and the grooves do not align, tighten (or loosen) the nut very slightly, just enough to align them. Once the cotter pin is inserted, spread the ends sufficiently to lock the pin in place. Propeller nut torque specifications are as follows: • For 3 and 4/5 hp motors: there is no specification, snug the nut making sure the cotter pin holes are exposed • 6-15 hp motors: 12.5 ft. lbs. (17 Nm) • 20 hp and larger inline motors: 22ˇ25 ft. lbs. (30-35 Nm) • V4 and V6 motors: 40 ft. lbs. (55 Nm) 16. Connect the spark plug leads and/or the negative battery cable, as applicable. Jet Drive Impeller + See Figure 82 A jet drive motor uses an impeller enclosed in a jet drive housing instead of the propeller used by traditional gearcases. Outboard jet drives are designed to permit boating in areas prohibited to a boat equipped with a conventional propeller outboard drive system. The housing of the jet drive barely extends below the hull of the boat allowing passage in ankle deep water, white water rapids, and over sand bars or in shoal water which would foul a propeller drive. The outboard jet drive provides reliable propulsion with a minimum of moving parts. It operates, simply stated, as water is drawn into the unit through an intake grille by an impeller. The impeller is driven by the driveshaft off the powerhead's crankshaft. Thrust is produced by the water that is expelled under pressure through an outlet nozzle that is directed away from the stem of the boat. As the speed of the boat increases and reaches planing speed, only the very bottom of the jet drive where the intake grille is mounted facing downward remains in contact with the water. The jet drive is provided with a reverse-gate arrangement and linkage to permit the boat to be operated in reverse. When the gate is moved downward over the exhaust nozzle, the pressure stream is deflected (reversed) by the gate and the boat moves sternward. Conventional controls are used for powerhead speed, movement of the boat, shifting and power trim and tilt. INSPECTION + See Figure 83 Thejet impeller is a precisely machined and dynamically balanced aluminum spiral. Close observation will reveal drilled recesses at exact Fig. 82 Instead of a traditional gearcase, jet drives use an impeller (it's sort of an enclosed propeller) mounted in a jet drive housing that just barely extends below the boat's hull locations used to achieve this delicate balancing. Excessive vibration of the jet drive may be attributed to an out-of-balance condition caused by the jet impeller being struck excessively by rocks, gravel or from damage caused by cavitation "burn". The term cavitation "burnˇ is a common expression used throughout the world among people working with pumps. impeller blades, and forceful water movement. These "burns" occur on the jet impeller blades from cavitation air bubbles exploding with considerable force against the impeller blades. The edges of the blades may develop small dime-size areas resembling a porous sponge, as the aluminum is actually "eaten" by the condition ju..t described. Excessive rounding of the jet impeller edges will reduce efficiency and performance. Therefore, the impeller and intake grate (that protects it from debris) should be inspected at regular intervals. Before and after each use, make a quick visual inspection of the intake grate and impeller, looking for obvious signs of damage. Always ..lear any debris such as plastic bags, vegetation or other items that sometimes become entangled in the water intake grate before starting t..e ..otor. If th.. intake grate is damaged, do not operate the motor, or you will nsk .destroymg the impeller if rocks or other debris are drawn upward by the J..t dnve. If possible, replace a damaged grate before the next launch. Th1s makes inspection after use all that much more important. lmag1ne the disappointment if you only learn of a damaged grate while inspecting the motor immediately prior to the next launch. An obviously damaged impeller should be removed and either repaired or replaced depending on the extent of the damage. If rounding is detected, the impeller can be placed on a work bench and the edges restored to as sharp a condition as possible, using a file. Draw the file in only one direction. A back-and-forth motion will not produce a smooth edge. Take care not to nick the smooth surface of the jet impeller. Excessive nicking or pitting will create water turbulence and slow the flow of water through the pump. For more details on impeller replacement or service, please refer to the information on Jet Drives in the Gearcase section of this manual. CHECKING IMPELLER CLEARANCE + See Figure 84 and 85 Proper operation ofthe jet drive depends upon the ability to create maximum thrust. In order for this to occur the clearance between the outer edge of the jet drive impeller and the water intake housing cone wall should .. • ..ˇ MAINTENANCE & TUNE-UP 2-25 Fig. 83 Visually inspect the intake grate and impeller with each use Fig. 84 Jet drive impeller clearance is the gap between the edges of the impeller and its housing Fig. 85 Impeller clearance is adjusted using shims below and above the impeller be maintained at approximately 1/32 in. {0.79mm). This distance can be checked visually by shining a flashlight up through the intake grille and estimating the distance between the impeller and the casing cone, as indicated in the accompanying illustrations. But, it is not humanly possible to accurately measure this clearance by eye. Close observation between outings is fine to maintain a general idea of impeller condition, but, at least annually, the clearance must be measured using a set of long feeler gauges. *.,;. CAUTION Whenever working around the impeller, ALWAYS disconnect the negative battery cable and/or disconnect the spark plug leads to mak.e sure the engine cannot be accidentally started during service. Failure to heed this caution could result in serious personal injury or death in the event that the engine is started. When checking clearance, a feeler gauge larger than the clearance specification should not fit between the tips of the impeller and the housing. A gauge within specification should fit. but with a slight drag. A smaller gauge should fit without any interference whatsoever. Check using the feeler gauge at various points around the housing, while slowly rotating the impeller by hand. After continued normal use, the clearance will eventually increase. In anticipation of this the manufacturer mounts the impeller deep in a taperedhousing, and positi ons spacers beneath the impeller to hold it in position. The spacers are used to position the impeller along the driveshaft with the desired clearance bel\veen the jet impeller and the housing waiL When clearance has increased, spacers are removed from underneath the impeller and repositioned behind it, dropping the impeller slightly in the housing and thereby decreasing the clearance again. If adjustment is necessary, refer to the Jet Drive procedures under Gearcase in this manual for impeller removal, shimming and installation procedures. Followthe appropriate parts of the Removal & Disassembly, as well as Assembly procedures for impeller service. Anodes (Zincs) + See Figures 86, 87 and 88 The idea behind anodes (also known as sacrificial anodes) is simple: When dissimilar metals are dunked in water and a small electrical current is leaked between or amongst them, the lessˇnoble metal (galvanically speaking) is sacrificed {corrodes). The zinc alloy of which most anodes are made is designed to be less noble than the aluminum alloy of which your outboard is constructed. If there's any electrolysis, and there almost always is, the inexpensive zinc anodes are consumed in lieu of the expensive outboard motor. • We say the zinc allow of which MOST anodes are made because the anodes recommended for fresh water applications may also be made of a different material. Some manufacturers recommend that you use magnesium anodes for motors used solely in freshwater applications. Magnesium offers a better protection against corrosion for aluminum motors, however the ability to offer this protection generally makes it too active a material for use in salt water applications. Because zinc is the more common material many people (including us) will use the word zinc interchangeably with the word anode, don't let this confuse you as we are refernng equally to all anodes, whether they are made of zinc or magnesium. These zincs require a little attention in order to make sure they are capable of performing their function. Anodes must be solidly attached to a clean mounting site. Also, they must not be covered with any kind of paint, wax or marine growth. Fig. 86 Extensive corrosion of an anode suggests a problem or a complete disregard for maintenance Fig. 87 Although most Yamaha's use a trim tab anode, others are normally found on the gearcase and powerhead Fig. 88 Lead wires are used to protect bracketed components 2ˇ26 MAINTENANCE & TUNE-UP INSPECTION SERVICING + See Figures 89 thru 97 + See Figures 86, 87 and 88 Visually inspect the anodes, especially gearcase mounted ones, before and after each use. You'll want to know right away if it has become loose or fallen off in service. Periodically inspect them closely to make sure they haven't eroded too much. At a certain point in the erosion process, the mounting holes start to enlarge, which is when the zinc might fall off. Obviously, once this happens your engine no longer has any protection. Generally, a zinc anode is considered worn if it has shrunken to 213 or less than the original size. To help judge this, buy a spare and keep it handy (in the boat or tow vehicle for comparison). If you use your outboard in salt water or brackish water, and your zincs never seem to wear, inspect them carefully. Paint, wax or marine growth on zincs will insulate them and prevent them from performing their function properly. They must be left bare and must be installed onto bare metal of the motor. If the zincs are installed properly and not painted or waxed, inspect around them for sings of corrosion. If corrosion is found, strip it off immediately and repaint with a rust inhibiting paint. If in doubt, replace the zincs. On the other hand, if your zinc seems to erode in no time at all, this may be a symptom of the zincs themselves. Each manufacturer uses a specific blend of metals in their zincs. If you are using zincs with the wrong blend of metals, they may erode more quickly or leave you with diminished protection. At least annually or whenever an anode has been removed or replaced, check the mounting for proper electrical contact using a multi-meter. Set the multi-meter to check resistance (ohms), then connect one meter lead to the anode and the other to a good, unpainted or un-corroded ground on the motor. Resistance should be very low or zero. If resistance is high or infinite, the anode is insulated and cannot perform its function properly. Depending on your boat, motor and rigging, you may have anywhere from one to four (or even more) anodes. Regardless of the number, there are some fundamental rules to follow that will give your boat and motor's sacrificial anodes the ability to do the best job protecting your boat's underwater hardware that they can. • On most models the trim tab serves as the gearcase anode. If the anode must be replaced, make an alignment mark between the anode and gearcase before removal, then transfer the mark to the replacement anode to preserve trim tab adjustment. If the boat pulls to one side after replacement and did not previously, refer to the Trim Tab Adjustment procedure in the Gearcase section to correct this condition. All motors covered by this manual are equipped with at least one gearcase anode, normally mounted in, on, or near the anti-ventilation plate. Many of the motors covered by this manual also have a powerhead mounted anode and/or an engine clamp bracket anode. Location of the powerhead zincs will vary slightly from motor-to-motor including mounting bosses specifically cast in the motor. Most multi-cylinder motors are equipped with one or more anodes on the engine mount clamp bracket. • Many Yamaha motors are equipped with anodes in the water jackets surrounding the cylinders. These anodes can only be accessed by removing the cylinder head. Obviously this is not a common maintenance practice, but could easily be justified every 5 years or 500 hours of operation or so. It will give you the opportunity to check the pistons and combustion chambers for wear, scoring or carbon deposits as well. Fig. 89 Some trim tab anodes are bolted Fig. 90 ..• while others are fastened from Fig. 91 Remove the rubber cover. . . from below ... the top Fig. 92 .•. to access the anode retaining Fig. 94 •.• or more anodes on the transom bolt Fig. 93 Many motors have one .. . bracket MAINTENANCE & TUNE-UP 2-27 Some people replace zincs annually. This may or may not be necessary, depending on the type of waters in which you boat and depending on whether or not the boat is hauled witheach use or left in for the season. Bther way, it is a good idea to remove zincs at least annually in order to make sure the mounting surfaces are still clean and free of corrosion. The first thing to remember is that zincs are electrical components and like all electrical components, they require good clean connections. So after you've undone the mounting hardware you want to get the zinc mounting sites clean and shiny. Get a piece of coarse emery cloth or some 80-grit sandpaper. Thoroughly rough up the areas where the zincs attach (there's often a bit of corrosion residue in these spots}. Make sure to remove every trace of corrosion as it could insulate the zinc from the motor. Zincs are attached with stainless steel machine screws that thread into the mounting for the zincs. Over the course of a season, this mounting hardware is inclined to loosen. Mountthe zincs and tighten the mounting hardware securely. Tap the zincs with a hammer hitting the mounting screws squarely. This process tightens the zincs and allows the mounting hardware to become a bit loose in the process. Now, do the final tightening.This will insure your zincs stay put for the entire season. Fig. 95 Many Yamahas use anodes in cooling passages under the cylinder head.•. Fig. 96 •.•they are only accessible when the cylinder head/chamber cover is removed Fig. 97 Other Yamahas have anodes mounted under covers in small powerhead bores BOAT MAINTENANCE Batteries • See Figures 98 and 99 Batteries require periodic servicing, so a definite maintenance program will help ensure extended life. A fai!ure to maintain the battery in good order can prevent it from properly charging or properly performing its job even when fully charged. Low levels of electrolyte in the cells, loose or dirty cable connections at the battery terminals or possibly an excessively dirty battery top can all contribute to an improperly functioning battery. So battery maintenance, first and foremost, involves keeping the battery full of electrolyte, properly charged and keeping the casing/connections clean of corrosion or debris. If a battery charges and tests satisfactorily butstill fails to perform properly in service, one of three problems could be the cause. t. An accessory left on overnight or for a long period of time can discharge a battery. 2. Using more electrical power than the stator assembly or lighting coil can replace would slowly drain the battery during motor operation, resulting in an undercharged condttion. 3. Adefect in the charging system. A faulty stator assembly or lighting coil, defective regulator or rectifier or high resistance somewhere in the system could cause the battery to become undercharged. • For more information on marine batteries, please refer to BAffiRY In the Ignition and Electrical Systems section. MAINTENANCE • See Figures 99 thru 102 ..SY Electrolyte Level The most common and important procedure in battery maintenance is checking the electrolyte level. On most batteries, this is accomplished by removing the cell caps and visually observing the level in the cells. The bottom of each cell normally is equipped with a split vent which will cause the surface of the electrolyte to appear distorted when it makes contact. When the distortion first appears at the bottom of the split vent, the electrolyte level Is correct. Smaller marine batteries are sometimes equipped with translucent cases that are printed or embossed with high and low level markings on the side. On some of these, shining a flashlight through the battery case will help make it easier to determine the electrolyte level. During hot weather and periods of heavy use, the electrolyte level should be checked more often than during normal operation. Add distilled water to bring the level of electrolyte in each cell to the proper level. Take care not to overfill, because adding an excessive amount of water will cause loss of electrolyte and any loss will result in poor performance, short battery life and will contribute quickly to corrosion. Fig. 98 Explosive hydrogen gas is released from the batteries in a discharged state. This one exploded when something ignited the gas. Explosions can be caused by a spark from the battery terminals or jumper cables 2-28 MAINTENANCE & TUNE-UP :+:.lc WARNING Take care to prevent any of the neutralizing solution fromentering the cells as it will quickly neutralize the electrolyte (ruining the battery). Poor contact at the terminals will add resistance to the charging circuit. This resistance may cause the voltage regulator to register a fully charged battery and thus cut down on the stator assembly or lighting coil output adding to the low battery charge problem. At least once a season, the battery terminals and cable damps should be cleaned. Loosen the clamps and remove the cables, negative cable first. On batteries with top mounted posts, if the terminals appear stuck, use a puller specially made for this purpose to ensure the battery casing is not damaged. NEVER pry a terminal off a battery post. Battery terminal pullers are inexpensive and available in most parts stores. Clean the cable clamps and the battery terminal with a wire brush until all corrosion, grease, etc., is removed and the metal is shiny. It is especially important to clean the inside of the clamp thoroughly (a wire brush or brush part of a battery post cleaning tool is useful here), since a small deposit of foreign material or oxidation there will prevent a sound electrical connection and inhibit either start.ing or charging. It is also a good idea to apply some dielectric grease to the terminal, as this will aid in the prevention of corrosion. • Neveradd electrolyte from another battery. Use only distilled water. Eventap water maycontain minerals or additives that will promote corrosion on the battery plates, so distilled water is always the best solution. Although less common in marine applications than other uses today, sealed maintenance-free batteries also require electrolyte level checks, through the window built into the tops of the cases. The problem for marine applications is the tendency for deep cycle use to cause electrolyte evaporation and electrolyte cannot be replenished in a sealed battery. Atthough, more and more companies are producing a maintenance-free batteries for marine applications and their success should be noted. The second most important procedure in battery maintenance is periodically cleaning the battery terminals and case. Cleaning Dirt and corrosion should be cleaned from the battery as soon as it is discovered. Any accumulation of acid film or dirt will permit a small amount of current to flow between the terminals. Such a current flow will drain the battery over a period of time. Clean the exterior of the battery with a solution of diluted ammonia or a paste made from baking soda and water. This is a base solution that will neutralize any acid that may be present. Flush the cleaning solution off with plenty of clean water. Fig. 99 Ignoring a battery (and corrosion) to this extentis asking for it to fail After the clamps and terminals are clean, reinstall the cables, negative cable last, do not hammer the clamps onto battery posts. Tighten the clamps value less than 12 volts, but can normally be brought back to 12 volts through recharging. Of course a battery with one or more shorted or un- Fig. 100 Place a battery terminal tool over posts, then rotate back and forth .•• Fig. 1 01 ... until the internal brushes expose a fresh, clean surface on the post Fig. 102 Clean the insides of cable ring terminalsusing the tool's wire brush securely but do not distort them. To help slow or prevent corrosion, give the clamps and terminals a thin external coating of grease after installation. Check the cables at the same time that the terminals are cleaned. If the insulation is cracked or broken or if its end is frayed, that cable should be replaced with a new one of the same length and gauge. TESTING ...Ž TE + See Figure 1 03 A quick check of the battery is to place a voltmeter across the terminals. Although this is by no means a clear indication, it gives you a starting point when trying to troubleshoot an electrical problem that could be battery related. Most marine batteries will be of the 12 volt DC variety. They are constructed of 6 cells, each of which is capable of producing slightly more than two volts, wired in series so that total voltage is 12 and a fraction. A fully charged battery will normally show more than 12 and slightly less than 13 volts across its terminals. But keep in mind that just because a battery reads 12.6 or 12.7 volts does NOT mean it is fully charged. It is possible for it to have only a surface charge with very little amperage behind it to maintain that voltage rating for long under load. A discharged battery will read some Fig. 103 A hydrometer is the best method for checking battery condition chargeable cells will also read less than 12, but it cannot be brought back to 12+ ..?Its after chargin... For thi.. re..son, the best method to check battery condition on most manne battenes IS through a specific gravity check or a load test. A hydrometer is a device that measures the density of a liquid when compared to water (specific gravity). Hydrometers are used to test batteries by measuring. '!le percentage of sulfuric acid in the battery electrolyte in terms of grav1ty. When the condition of the battery drops from fully charged to the ac1d is converted to water as electrons leave the solution and enter the plates, causing the specific gravity of the electrolyte to drop. It may not be common knowledge but hydrometer floats are calibrated for use at 80°F (27°C). If the_ hydrometer is used at any other temperature, hotter or colder, a correction factor must be applied. • Remember, a liquid will expand if it is heated and will contract if cooled. Such expansion and contraction will cause a definite change in the specific gravity of the liquid, in this case the electrolyte. . A quality have a thermometerltemperature correction table 1n the l..wer as Illustrated in the accompanying illustration. By measu..ng the a1r temperatur.. around the battery and from the table, a correct1on factor may ..e applied to the specific gravity reading of the hydrometer float. In th1s manner, an accurate determination may be made as to the condition of the battery. When using a hydrometer, pay careful attention to the following points: 1. Never attempt to take a reading immediately after adding water to the battery. Allow at 1/4 hour of charging at a high rate to thoroughly mix the electrolyte the new water. This time will also allow for the necessary gases to be created. 2. Always be sure the hydrometer is clean inside and out as a precaution against contaminating the electrolyte. . 3. If a_ thermometer is an integral part of the hydrometer, draw liquid into II several t1mes to ensure the correct temperature before taking a reading. 4. Be sure to hold the hydrometer vertically and suck up liquid only until the float is free and floating. 5.Af.Nays ..old th.. hydrometer at eye level and take the reading at the surface ..f the liqu1d w1t.. the float free and floating. 6. D1sregard ..he slight curvature appearing where the liquid rises against the float stem. Th1s phenomenon IS due to surface tension. MAINTENANCE & TUNE-UP 2-29 7. D? not drop any of battery fluid on the boat or on your clothing, because 11 IS extremely Use water and baking soda to neutralize any battery liquid that does accidentally drop. 8. Afterdrawing electrolyte from the battery cell until the float is barely free, note the level of the liquid inside the hydrometer. If the level is within the charged (usually green) band range for all cells, the condition of the battery is satisfactory. If the level is within the discharged (usually white) band for all cells, the battery is in fair condition . . 9. If t..e level is within the gre..n or white band for all cells except one, wh1ch reg1..ters. 1n the red, the cell IS shorted internally. No amount of charg..ng w1ll bnng the battery back to satisfactory condition. 10. If the level in all cells is about the same, even if it falls in the red band, the battery may be recharged and returned to service. If the level fails to rise above the red band after charging, the only solution is to replace the battery.• An ..llernate way of testing a battery is to perform a load test using a spec1al ..arbon-Pile Load Test..r. These days most automotive and many manne parts stores contain a tester and will perform the check for free (hoping ..hat your battery will fail and they can sell youanother). Essentially a load test involves placing a specified load !current drain/draw) on .. f..lly-charged battery and checkin.. to see how 1t performs/recovers. Th1s IS the only way to test the condition of a sealed maintenance-free battery. STORAGE SY . If the ..oat is to be laid up (placed into storage) for the winter or anytime itIS not gomg to be used for more than a few weeks, special attention must be g1ven to the battery. This is necessary to prevent complete discharge and/or poss1ble damage to the terrmnals and wiring. Before putting the boat in storage, d1sc.mnect and remove the batteries. Clean them thoroughly of any d1rt or corros1on and then charge them to full specific gravity readings. After they are fully charged, store them in a clean cool dry place where they will not ..e damaged or knocked over, preferably on a couple blocks of wood. Stonng the battery up off the deck, will permit air to circulate freely around and under the battery and will help to prevent condensation. Never store the battery with.anythin.. on t..p of it or cover the battery in such .. manner as to prevent a1r from irculating around the filler caps. All ..attenes, both new .and old, will discharge during periods of storage, more so 1f they are . hot th..n 1f they remain oool. Therefore, the electrolyte level and the spec1flc grav1ty should be checked at regular intervals. A drop in the specific gra..ity reading is cause to charge them back to a full reading. In cold climates, care should be exercised in selecting the battery storage area. A fully-charged battery will freeze at about 60°F below zero. The electrolyte of a discharged battery, almost dead, will begin forming ice at about 19°F above zero. • For more informali?.. on batteries and the engine electrical systems, please refer to the lgmtlon and Electrical section of this manual. Fiberglass Hull INSPECTION AND CARE • See Figures 104, 105 and 106 _Fiberglass reinforced plastic hulls are tough, durable and highly resistant to 1mpact. However, like any other material they can be damaged. One of the advantages of this type of construction is the relative ease with which it may be repaired. . A fiberglass hull has almost no internal stresses. Therefore, when the hull IS broken or stove-in, it retains its true form. It will not dent to take an out-ofshape set. When the hull sustains a severe blow, the impact will be either absorbed by deflection of the laminated panel or the blow will result in a definite, localized break. In addition to hull damage and other stiffening structures attached to the hull may ..Jso be and therefore, should be checked. Repairs are usually confined to the general area of the rupture. • '0' 2-30 MAINTENANCE & TUNE-UP Fig. 104 The best way to care for a fiberglass hull is to wash it thoroughly Fig. 105 1f marine growth is a problem, apply a coating of anti-foul bottom paint Fig. 106 Fiberglass, vinyl and rubber care products, like those from Meguiar's protect your boat • The best way to care for a fiberglass hull is to wash it thoroughly, immediately after hauling the boat while the hull is still wet. The next best way to care for your hull is to give it a waxing a couple of times per season. Your local marina or boat supply store should be able to help you find some high quality boat soaps and waxes. A foul bottom can seriously affect boat performance. This is one reason why racers, large and small, both powerboat and sail, are constantly giving attention to the condition of the hull below the waterline. In areas where marine growth is prevalent, a coating of vinyl, anti-fouling bottom paint should be applied if the boat is going to be left in the water for extended periods of time such as all or a large part of the season. If growth has developed on the bottom, it can be removed with a diluted solution of muriatic acid applied with a brush or swab and then rinsed with clear water. Always use rubber gloves when working with Muriatic acid and take extra care to keep it away from your face and hands. The fumes are toxic. Therefore, work in a well-ventilated area; or if outside, keep your face on the windward side of the work. • If marine growth is not too severe you may avoid the unpleasantness of working with muriatic acid by trying a power washer instead. Most marine vegetation can be removed by pressurized water and a little bit of scrubbing using a rough sponge (don't use anything that will scratch or damage the surface). Barnacles have a nasty habit of making their home on the bottom of boats that have not been treated with anti-fouling paint. Actually they will not harm the fiberglass hull but can develop into a major nuisance. If barnacles or other crustaceans have attached themselves to the hull, extra work will be required to bring the bottom back to a satisfactorycondition. First, if practical, put the boat into a body of fresh water and allow it to remain for a few days. A large percentage of the growth can be removed in this manner. If this remedy is not possible, wash the bottom thoroughly with a high-pressure fresh water source and use a scraper. Small particles of hard shell may still hold fast. These can be removed with sandpaper. TUNE-UP Introduction to Tune-Ups A proper tune-up is the key to long and trouble-free outboard life and the work can yield its own rewards. Studies have shown that a properly tuned and maintained outboard can achieve better fuel economy than an out-ofˇ tune engine. As a conscientious boater, set aside a Saturday morning, say once a month, to check or replace items which could cause major problems later. Keep your own personal log to jot down which services you performed, how much the parts cost you, the date and the number of hours on the engine at the time. Keep all receipts for such items as oil and filters, so that they may be referred to in case of related problems or to determine operating expenses. These receipts are the only proof you have that the required maintenance was performed. In the event of a warranty problem on newer engines, these receipts will be invaluable. Interior INSPECTION AND CARE No one wants to walk around in bare feet on a boat whose deck or carpet is covered in fish guts right? It's not just a safety hazard, it's kind of nasty. Taking time to wash down and clean your boat's interior is just as important to the long term value of your boat as it is to your enjoyment. So take time, after every outing to make sure your baby is clean on the inside too. Always try to find gentle cleaners for your vinyl and plastic seats. Harsh chemicals and abrasives will do more harm then good. Take care with guests aboard, as more than one brand of sun-tan lotion has been know to cause stains. Some people get carried away, forbidding things like cheesy coated chips/snacks or mustards on board. Don't let keeping your boat clean so much of an obsession that you forget to enjoy it, just keep a bottle of cleaner handy for quick spill clean-ups. And keeping it handy will ensure you'll be more likely to wipe things down after a fun-filled outing. Be sure to always test a cleaner on a hidden or unexposed area of your carpet or vinyl before soaking things down with it. If it does not harm or damage the color of yourfinish, you're good to go. When we trailer our boats, we sometimes find it more convenient to hit a spray-it-yourself car wash on the way home. This gives us a chance to spray down the boat hull, trailer and tow vehicle before we get home and turn our attention to engine flushing and wiping down/cleaning the interior. If you're lucky enough to have snap out marine carpet, remove it and give it a good wash down once in a while. This allows you to spray down the deck as well. Hang the carpet to dry and reinstall once it is ready. If you've got permanently installed marine carpet, you can spray it down too; just make sure you can give it a chance to dry before putting the cover back on. • For permanently installed marine carpet, try renting a rug steamˇ cleaner at least once a season and give it a good deep cleaning. We like to do it at the beginning and the end of each season! The efficiency, reliability, fuel economy and enjoyment available from boating are all directly dependent on having your outboard tuned properly. The importance of performing service work in the proper sequence cannot be over emphasized. Before making any adjustments, check the specifications. Never rely on memory when making critical adjustments. Before tuning any outboard, insure it has satisfactory compression. An outboard with worn or broken piston rings, burned pistons or scored cylinder walls, will not perform properly no matter how much time and expense is spent on the tune-up. Poor compression must be corrected or the tune-up will not give the desired results. The extent of the engine tune-up is usually dependent on the time lapse since the last service. In this section, a logical sequence of tune-up steps will be presented in general terms. If additional information or detailed service work is required, refer to the section of this manual containing the appropriate instructions. Tune-Up Sequence A tune-up can be defined as pre-determined series of procedures (adjustments, tests and worn component replacements) that are performed to bring the engine operating parameters back to original condition. The series of steps are important, as the later procedures (especially adjustments) are dependant upon the earlier procedures. In other words, a procedure is performed only when subsequent steps would not change the result of that procedure (this is mostly for adjustments orsettings that would be incorrect alter changing another part or setting). For instance, fouled or excessively worn spark plugs may affect engine idle. II adjustments were made to the idle speed or mixture of a carbureted engine before these plugs were cleaned or replaced, the idle speed or mixture might be wrong alter replacing the plugs. The possibilities of such an effect become much greater when dealing with multiple adjustments such as timing, idle speed and/or idle mixture. Therefore, be sure to follow each of the steps given here. Since many of the steps listed here are lull procedures in themselves, refer to the procedures of the same name in this section for details. • Computer controlled ignition and fuel components on more and more modern outboards have lessoned the amount of steps necessary for a pre-season tune-up, but not completely eliminated the need for replacing worn components. EFI and HPDI motors may not allow for many (or any) timing or mixture adjustments, however they still have mechanical and electrical components that wear making compression checks, spark plug/wire replacement, and component inspection steps all that much more important. A complete pre-season tune-up should be performed at the beginning of each season or when the motor is removed from storage. Operating conditions, amount of use and the frequency of maintenance required by your motor may make one or more additional tune-ups necessary during the season. Perform additional tune-ups as use dictates. 1. Before starting, inspect the motor thoroughly lor signs of obvious leaks, damage and loose or missing components. Make repairs, as necessary. "".->t. CAUTION We can't emphasize enough how important is ihis first step, ESPECIALLY on HPDI motors. The extreme high-pressure fuel system of these motors makes fuel system/line integrity a very important safety issue. 2. Check all accessible bolts and fasteners and tighten any that are loose. 3. For many decades, a standard part of the outboard tune-up procedure was to re-torque the cylinder head/cover bolts. Typically manufacturers advised you to follow the applicable steps of the cylinder the cylinder head/cover removal and installation procedures. Each of the bolts would be loosened slightly using the reverse of the tightening sequence, then re-torqued using one or more passes of the tightening sequence, as directed. Refer to the procedures under Powerhead lor details. However, Yamaha is somewhat obscure about the need to do this on their modern outboards. Yamaha specifically mentions that you should NOT do this on some 4-stroke motors. But they do specifically mention that you SHOULD do this to the 3, 4/5 hp and 25/35 hp (3-cylinder), 50/60170 hp (849cc) and 65J-90 hp (1140cc) motors. Also, they do not specifically include or exclude the cylinder head bolts from the maintenance requirement of checking/tightening ALL BOLTS AND NUTS listed in most of the service charts for all of their other motors. So we'll leave it to your judgment whether or not you want to include the cylinder head/cover bolts on other Yamaha motors, but it is probably not a bad idea to include it annually an'fNay (if in doubt, check with your local marine dealer). 4. Perform a compression check to make sure the motor is mechanically readylor a tune-up. An engine with low compression on one or more cylinder should be overhauled, not tuned. Atune-up will not be successful without sufficient engine compression. Refer to the Compression Testing in this section. • If this tune-up is occurring immediately after removing an engine from storage, be sure to start and run the motor using the old plugs first (if possible) while burning off the fogging oil. Then install the new spark plugs once the compression test is completed! MAINTENANCE & TUNE-UP 2-31 5. Since the spark plugs must be removed for the compression check, take the opportunity to inspect them thoroughly for signs of oil fouling, carbon fouling, damage due to detonation, etc. Clean and re-gap the plugs or, better yet, install new plugs as no amount of cleaning will precisely match the performance and life of new plugs. Refer to Spark Plugs, in this section. Also, this is a good time to check the spark plug wires as well. Please refer tn Spark Plug Wires, in this section. • We don't care how little you use your motor, there is usually no excuse for not installing new plugs at the beginning of each season. If only because when storing a motor the fogging oil will go a long way to fouling even a decent set of spark plugs. Remember, the secondary ignition circuit is the most likely performance problem that occurs on an outboard. 6. Visually inspect all ignition system components lor signs of obvious defects. Look lor signs of burnt, cracked or broken insulation. Replace wires or components with obvious defects. If spark plug condition suggests weak or no spark on one or more cylinders, perform ignition system testing to eliminate possible worn or defective components. Refer to the Ignition System Inspection procedures in this section and the Ignition and Electrical System section. 7. Visually inspect all engine wiring and, if equipped, the battery and starter motor. A quick starter motor draw test can tell you a lot about the condition of your electrical starting system. 8. Remove and clean (on serviceable filters) or replace the inline filter and/or fuel pump filter, as equipped. Refer to the Fuel FiHer procedures in this section. Perform a thorough inspection of the fuel system, hoses and components. Replace any cracked or deteriorating hoses. II carburetor adjustment or overhaul is necessary, perform these procedures before proceeding. 9. Pressurize the fuel system according to the procedures found in the Fuel System section, then check carefully for leaks. Again, this is important on all motors, but even more so on EFI motors and critical on HPDI engines! 10. Perform engine Timing and Synchronization adjustments as described in this section. • Although many of the motors covered here allow for certain ignition timing and, if applicable, carburetor adjustment procedures, none of them require the level of tuning attention that was once the norm. Many of the motors are equipped with electronic ignition systems that limit or eliminate timing adjustments. Carburetors used on many of these Yamahas are U.S. EPA regulated and contain few mixture adjustments. The air/fuel mixture is completely computer controlled on fuel injected motors and allows for no adjustment. 11. Except for jet drive models, remove the propeller in order to thoroughly check lor leaks at the shaft seal. Inspect the propeller or impeller condition, look for nicks, cracks or other signs of damage and repair or replace, as necessary. If available, install a test wheel to run the motor in a test tank after completion of the tune-up. If no test wheel is available, lubricate the shalt/splines, then install the propeller or rotor. Refer to the procedures lor Propeller or Jet Drive Impeller in this section, as applicable. 12. Change the gearcase oil as directed under the Gearcase Oil procedures in this section. If you are conducting a pre-season tune-up and the oil was changed immediately prior to storage this is not necessary. But, be sure to check the oil level and condition. Drain the oil anyway if significant contamination is present. • Anytime large amounts of water or debris is present in the gearcase oil, be sure to troubleshoot and repair the problem before returning the gearcase to service. The presence of water may indicate problems with the seals, while debris could a sign that overhaul is required. 13. Perform a test run of the engine to verifyproper operation of the starting, fuel, oil and cooling systems. Although this can be performed using a flush/lest adapter or even on the boat itself (if operating with a normal load/passengers), the preferred method is the use of a test tank. Keep in mind that proper operation without load and at low speed (on a llusMest adapter) doesn't really tell you how well the motor will run under load. II possible, run the engine, in a test tank using the appropriate test wheel. Monitor the cooling system indicator stream to ensure the water pump is working properly. Once the engine is fully warmed, slowly advance the engine to wide-open throttle, then note and record the maximum engine speed. Refer to the Tune-Up Specifications chart to compare engine speeds 2-32 MAINTENANCE & TUNE-UP If a specification is not available for your motor, put the most weight on a comparison of the readings from the other cylinders on the same motor (or readings when the motor was new). When taking readings during the compression check, repeat the procedure a few times for each cylinder, recording the highest reading for that cylinder. Then, for all multi-cylinder motors, the compression reading on the lowest cylinder should within 30 psi (207 kPa) of the highest reading (and still within specification if one is given in the Engine Specifications chart for that motor). If not, consider 15-30% to be the absolute limit. If the reading in the lowest cylinder is less than 70 % of the reading in the highest cylinder, it's time to find and remedy the cause. • If the powerhead has been in storage for an extended period, the piston rings may have relaxed. This will often lead to initiallx low and misleading readings. Always run an engine to normal operating temperature to ensure ..hat the readings are accurate. • If you've never removed the spark plugs from this cylinder head before, break each one loose and retighten them before starting the motor in order to make sure they will not seize in the head once it is warmed. Better yet, remove each one and coat the threads very lightly with some fresh anti-seize compound. Yamaha has modified the cylinder head design on some V4 and V6 models in an attempt to keep the temperature of each head the same. This action has changed the shape of the combustion chamber, and therefore the volume and compression pressure of each cylinder. As a general rule, the pressure between pairs of cylinders which share the same crankshaft throw, should be approximately the same. Cylinder No. 1 should be the same as cylinder No. 2; cylinder No. 3 should be the same as cylinder No. 4; and so on. Typically, on a V6 powerhead, cylinder No. 1 and No. 2 will have the highest compression pressure. Cylinder No. 5 and No. 6 will have the lowest compression pressure. Prepare the engine for a compression test as follows: 1. Run the engine until it reaches operating temperature. The engine is at operating temperature a few minutes after the powerhead becomes warm to the touch and the stream of water exiting the cooling indicator becomes warm. II the test is perlormed on a cold engine, the readings will be considerably lower than normal, even if the engine is in perfect mechanical condition. 2. Label and disconnect the spark plug wires. Always grasp the molded cap and pull it loose with a twisting motion to prevent damage to the connection. 3. Clean all dirt and foreign material from around the spark plugs, and then remove all the plugs. Keep them in order by cylinder for later evaluation. Fig. 107 Removing the high tension lead. Always use a twist and pull motion on the boot to prevent damage to the wire with the test propeller minimum rpm specifications. If engine speeds are below specifications, yet engine compression was sufficient at the beginning of this procedure, recheck the fuel and ignition system adjustments (as well as the condition of the prop if you're not using a test wheel). Compression Testing The quickest way to gauge the condition of an internal combustion engine is through a compression check. In order for an internal combustion engine to work properly, it must be able to generate sufficient compression in the combustion chamber to take advantage of the explosive force generated by the expanding gases after ignition. If the combustion chambers or reed valves are worn or damaged in some fashion as to allow pressure to escape, the engine cannot develop sufficient horsepower. Under these circumstances, combustion will not occur properly meaning that the air/fuel mixture cannot be set to maximize power and minimize emissions. Obviously, it is useless to try to tune an engine with extremely low or erratic compression readings, since a simple tune-up will not cure the problem. An engine with poor compression on one or more cylinders should be overhauled. . The pressure created in the combustion chamber may be measured w1th a gauge that remains at the highest reading it measures during the action of a one-way valve. This gauge is inserted into the spark plug hole and held or threaded in position while the motor is cranked. A compression test will uncover many mechanical problems that can cause rough running or poor perlormance. If the powerhead shows any indication of overheating, such as discolored or scorched paint, inspect the cylinders visually through the spark plug hole or transfer ports for possible scoring. It is possible for a cylinder with satisfactory compression to be scored slightly. Also, check the water pump, since a faulty water pump can cause an overheating condition. TUNE-UP COMPRESSION CHECK TE • See Figures 107, 108 and 109 • Acompression check requires a compression gauge and a spark plug port adapter that matches the plug threads of your motor. When analyzing the results of a compression check, generally the actual amount of pressure measured during a compression check is not quite as important as the variation from cylinder-to-cylinder on the same motor. For multi-cylinder powerheads, Yamaha states that variations of up to 30 psi {207 kPa) may be considered normal. However, on single cylinder powerheads, a drop of about 15 psi (103 kPa) from the normal compression pressure you established when it was new is cause for concern (you did do a compression test on it when it was new, didn't you?). • On V-models the variations should appear between cylinders in a vertical bank, i.e. the top versus the middle or the top and middle versus the bottom cylinders. However, less of a variation should exist between the same cylinder in the port and starboard banks (i.e. the top on both banks, the middle on both banks or the bottom on both banks). Ok, for the point of arguments sake let's say you bought the engine used or never checked compression the first season or so, assuming it wasn't something you needed to worry about. You're not alone, many of us have done that. But now that you're reading this it is your chance to take the data and note it for future. For many years Yamaha did not publish much in the way of specific compression specifications for the amount of compression each of their engines should generate, a general rule of thumb that can be applied is that generally internal combustion engines should generate at least 1 00 psi (690 kPa). However, a quick check of the specifications that Yamaha HAS published to date shows a range of about 78 psi (556 kPa) to 153 psi (1079 kPa) on 2-stroke motors. • To see if Yamaha has published a specification for your particular engine, please check the Engine Specifications charts in the Powerhead section. If a specification is available it will be listed under Compression. • On most Yamaha motors you can disable the ignition system by leaving the safety lanyard disconnected but still use the starter motor to turn the motor. This is handy for things like testsor distributing fogging oil. To be certain use a spark gap tester on one lead and crank the motor using the keyswitch. If no spark is present, you're good to go, if not, you'll have to ground the spark plug leads to the cylinder head. Fig. 108 The ignition must be disabled or all spark plugs must be grounded while making compression tests Fig. 109 The compression tester is threaded into an open spark plug port MAINTENANCE & TUNE-UP 2-33 4. Ground the spark plug leadsto the engine to renderthe ignition system inoperative while performing the compression check. *.7 CAUTION Grounding the spark plug leads not only protects the ignition system from potential damage that may be caused by the excessive load placed on operating the system with the wires disconnected, but more importantly, protects you from the dangers of arcing. The ignition system operates at extremely high voltage and could cause serious shocks. Also, keep in mind that you're cranking an engine with open spark plug ports which could allow any remaining fuel vapors to escape become ignited by arcing current. 5. Insert a compression gauge into the No. 1,top, spark plug opening. 6. Move the throttle to the wide open posijion in order to make sure the throttle plates arenotrestricting air flow. If necessary you may have to spin the propellershaft slowly by hand while advancing the throttle in order to get the shifter into gear. 7. Crank the engine with the starter through at least 4-5 complete strokes with the throttle at the wide-open position, to obtain the highest possible reading. Record the reading. • On electric start motors, it is very important to use a freshly charged cranking battery as a weakened battery will cause a slower than normal cranking speed, reducing the compression reading. 8. Repeat the test and record the compression for each cylinder. 9. A variation between cylinders isfar more important than the actual readings. A variation of more than 30 psi (207 kPa), between cylinders indicates the lower compression cylinder is defective. Not all engines will exhibit the same compression readings. In fact, two identical engines may not h..ve the same compression. Generally, the rule of thumb is that the lowest cylindershould be within 1 5-30% of the highest (difference between the two readings). 10. 1f compression is low in one or more cylinders, the problem may be worn, broken, or sticking piston rings, scored pistons or worn cylinders. LOW COMPRESSION Compression readings that are generally low indicate worn, broken, or sticking piston rings, scored pistons or worn cylinders, and usually indicate an engine that has a lot of hours on it Low compression in two adjacent cylinders (with normal compression in the other cylinders) indicates a blown head gasket between the low-reading cylinders. Other problems are possible (broken ring, hole burned in a piston), but a blown head gasket is most likely. • Use of an engine cleaner, available at any automotive parts house, will help to free stuck rings and to dissolve accumulated carbon. Follow the directions on the container. To test a cylinder or motor further, add a few drops of engine oil to the cylinderand recheck. • If compression is higher with oil added to the cylinder, suspect a worn or damaged piston. • If compression is the same as withoutoil, suspect one or more defective rings or a defective piston, butyou can also suspect oil seals or reed valves. • If compression is well above specification, suspect the carbon deposits are on the cylinder head and/or piston crown. Significant carbon deposits will lead to pre-ignition and other performance problems and should be cleaned (either using an additive or by removing the cylinder head for manual cleaning). Spark Plugs + See Figure 110 The spark plug performs four main functions: • First and foremost, itprovides spark for the combustion process to occur. • It also removes heat from the combustion chamber. • Its removal provides access to the combustion chamber (for inspection or testing) through a hole in the cylinder head. 2-34 MAINTENANCE & TUNE-UP • Itacts as a dielectric insulator lor the ignition system. It is important to remember that spark plugs do not create heat, they help remove it. Anything that prevents a spark plug from removing the proper amount of heat can lead to pre-ignition, detonation, premature spark plug failure and even internal engine damage, especially in 2-stroke engines. In the simplest of terms, the spark plug acts as the thermometer of the engine. Much like a doctor examining a patient, this "thermometer" can b.. used to effectively diagnose the amount of heat present 1n each combust1on chamber. Spark plugs are valuable tuning tools, when interpreted correctly. They will show symptoms of other problems and can reveal a great deal about the engine's overall condition. Evaluating the appearance of the spark plug's firing tip, gives visual cues to determine the engi..eˇs overal! ope....ting condition, get a feel for air/fuel ratios and even d1agnose dnveab1hty problems. As spark plugs grow older, they Jose their sharp edges as material from the center and ground electrodes slowly erodes away. As the gap between these two points grows, the voltage required to bridge this gap increases . proportionately. The ignition system must work harder to compen..at.. tor th1s higher voltage requirement and hence there is a greater rate of m1sf1res or incomplete combustion cycles. Each misfire means lost horsepower, reduced fuel economy and higher emissions. Replacing worn out spark plugs wrth new ones (with sharp new edges) effectively restores the ignition system's efficiency and reduces the percentage of misfires. restoring power, economy and reducing emissions. • Although spark plugs can typically be cleaned and re-gapped if they are not excessively worn, no amount of cleaning or re-gapping will return most spark plugs to original condition and it is usually best to just go ahead and replace them. How long spark plugs last will depend on a variety of factors, including engine compression, fuel used, gap, center/ground electrode matenal and the conditions in which the outboard is operated. Fig. 110 Damaged spark plugs. Notice the broken electrode on the left plug. The electrode must be found and retrieved prior to returning the powerhead to service SPARK PLUG HEAT RANGE + See Figures 111, 112 and 113 Spark plug heat range is the abilit.. ol the plug to dissipate. heat from . the combustion chamber. The longer the msulator (or the farther 11 extends 1nto the engine), the hotter the plug will operate; the shorter the insulator (t..e closer the electrode is to the engine's cooling passages) the cooler 11 w1ll operate. Selecting a spark plug with the proper heat range will ensure that the tip maintains a temperature high enough to prevent fouling, yet cool enough to prevent pre-ignition. A plug that absorbs little heat and remains too cool will quickly accumulate deposits of oil and carbon since it won't be able to burn them off. This leads to plug fouling and consequently to misfiring. A plug that T WE SHORTER THE PATH. THEFASTER TWEWEAl IS 015-SIPATEO ANO THE COOLER THE PLUG HEAVY LOAOS. HIGH SPEEDS SHORT Insulator Top Fa51 Heat Transter LOWER Helll Rangs COLO PLUG Fig. 111 Spark Plug heat range THE LONGŖA THE PATH. THE SLOWER THE HEAT IS DISˇ SIPATEO ANO THE HOTTER PlUG SHORT TRIP STOPˇANO-GO LONG lnsul..lot T•PSlo-Heal Ttanslet HIGHER Heal Range HOT P(UG absorbs too much heat will have no deposits but, due to the excessive heat, the electrodes will burn away quickly and might also lead to pre-ignition or other ignition problems. Pre-ignition takes place when plug tips get so hot that they glow . sufficiently to ignite the air/fuel mixture before the actual spark occurs. Th1s early ignition will usually cause a pinging during heavy loads and if not corrected, will result in severe engine damage. While there are many other things that can cause preˇignition, selecting the proper heat range spark plug will ensure that the spark plug itself is not a hot-spot source. • The manufacturer recommended spark plugs are listed in the TuneUp Specifications chart. Recommendations may also .. present ..n one or more labels affixed to your motor. When the label d1sagrees w1th the normally defer to the label as it may reflect a change that was mid-production and not reflected in the Yamaha service literature. REMOVAL & INSTALLATION + See Figures 114 thru 119 • New technologies in spark plug and ignition system design h..ve • greatly extended spark pl.ug life ..ver the ....ars. But, spark plug hfe Will still vary greatly With engrne tunrng, cond1t1on an.. usa.ge. In gener..l, 2ˇ stroke motors are a little tougher on plugs, especially 1f great care IS not taken to maintain proper oil/fuel mixtures on pre-mix motors. Typically spark plugs will require replacement once a season. The electrode on a new spark plug has a sharp edge but with use, this edge becomes rounded by wear, causing the plug gap to increase. As the gap increases, the plug's voltage requirement also increases. It a greater voltage to jump the wider gap and about two to as much voltage to fire a plug at high speeds than at idle. • Fouled plugs can cause hard-starting, engine mis-firing or other problems. You don't want that happening on the water. Take time, ..t least once a month to remove and inspect the spark plugs. Early srgns of other tuning or mechanical problems may be found on the plugs that could save you from becoming stranded or even allow you to address a problem before it ruins the motor. Tools needed for spark plug replacement include: a ratchet, ?hort extension, spark plug socket (there are two types; e1ther 13/16 mch or 5/8inch, depending upon the type of plug), a comb1natron spark plug gauge and gapping tool and a can of antiˇseize type compound. 1. When removing spark plugs from multi-cylinder motors, work on one at a time. Don't start by removing the plug wires all at once, because unless you number them, they may become mixed up. Take a minute before you begin and number the wires with tape. 2. For safety, disconnect the negative battery cable or turn the battery switch OFF. 3. lithe engine has been run recently, allow the engine to thoroughly cool (unless performing a compression check and then you should have already broken them loose once when cold and retightened them before MAINTENANCE & TUNE-UP 2-35 Fig. 112 Many Yamahas have a label which lists spark plug type and gap warming the motor, so they should have less ol a tendency to stick). Attempting to remove plugs from a hot cylinder head could cause the plugs to seize and damage the threads in the cylinder head, especially on aluminum heads! • To ensure an accurate reading during a compression check, the spark plugs must be removed from a hot engine. But, DO NOT force a plug if it feels like it is seized. Instead, wait until the engine has cooled, remove the plug and coat the threads lightly with anti-seize then reinstall and tighten the plug, then back off the tightened position a liHie less than 1/4 turn. With the plug(s) installed in this manner, rewarm the engine and conduct the compression check. Fig. 113 Though these days, at least in the US, most have an Emission Control label which contains that information 4. Carefully twist the spark plug wire boot to loosen it, then pull the boot using a twisting motion to remove it from the plug. Be sure to pull on the boot and not on the wire, otherwise the connector located inside the boot may become separated Irom the high-tension wire. • If removal is difficult (or on motors where the spark plug boot is hard to grip because of access) a spark plug wire removal tool is recommended as it will make removal easier and help prevent damage to the boot and wire assembly. Most tools have a wire loom that fits under the plug boot so the force of pulling upward is transmitted directly to the bottom of the boot. Fig. 116 Then unthread the plug using a ratchet and socket Fig. 119 To prevent corrosion, apply a small Fig. 117 ALWAYS thread plugs by hand to Fig. 118 .. . then use a torque wrench to amount of grease to the plug and boot prevent cross-threading ... tighten the plug to spec during installation 2-36 MAINTENANCE & TUNE-UP 5.Using compressed air (and safety glasses), blow debris from the spark plug area to assure that no harmful contaminants are allowed to enter the combustion chamber when the spark plug is removed. If compressed air is not available, use a rag or a brush to clean the area. Compressed air is available from both an air compressor or from compressed air in cans available at photography stores. In a pinch, blow upa balloon and use the escaping air to blow debris from the spark plug port(s). • Remove the spark plugs when the engine is cold, if possible, to prevent damage to the threads. If plug removal is difficult, apply a few drops of penetrating oil to the area around the base of the plug and allow it a few minutes to work. 6. Using a spark plug socket that is equipped with a rubber insert to properly hold the plug, turn the spark plug counterclockwise to loosen and remove the spark plug from the bore. ::.* WARNING Avoid the use of a flexible extension on the socket. Use of a flexible extension may allow a shear force to be applied to the plug. A shear force could break the plug off in the cylinder head, leading to costly and/or frustrating repairs. In addition, be sure to support the ratchet with your other hand -this will also help prevent the socket from damaging the plug. 7. Evaluate each cylinder's performance by comparing the spark condition. Check each spark plug to be sure they are from the same plug manufacturer and have the same heat range rating. Inspect the threads in the spark plug opening of the block and clean the threads before installing the plug. 8. When purchasing new spark plugs, always ask the dealer if there has been a spark plug change for the engine being serviced. Sometimes manufacturers will update the type of spark plug used in an engine to offer better efficiency or performance. 9. Always use a new gasket (if applicable). The gasket must be fully compressed on clean seats to complete the heat transfer process and to provide a gas tight seal in the cylinder. 10. Inspect the spark plug boot for tears or damage. If a damaged boot is found, the spark plug boot and possibly the entire wire will need replacement. 11. Check the spark plug gap prior to installing the plug. Most spark plugs do not come gapped to the proper specification. 12. Apply a thin coating of anti-seize on the thread of the plug. This is extremely important on aluminum head engines to prevent corrosion and heat from seizing the plug in the threads (which could lead to adamaged cylinder head upon removal). 13. Carefully thread the plug into the bore by hand. If resistance is felt before the plug completely bottoms, back the plug out and begin threading again. Do not use the spark plug socket to thread the plugs. Always carefully thread the plug by hand or using an old plug wire/boot to prevent the possibility of cross-threading and damaging the cylinder head bore. An old plug wireJboot can be used to thread the plug if you tum the wire by hand. Should the plug begin to cross-thread the wire will twist before the cylinder head would be damaged. This trick is useful when accessories or a deep cylinder head design prevents you from easily keepingfingers on the plug while it is threaded by hand. ** WARNING 14. Carefully tighten the spark plug to specification using a torque wrench, as follows: • 25/30 hp (496cc) 3-cylinder engines: 14 ft. lbs. (20 Nm) • All other engines: 18ft. lbs. (25 Nm) • Whenever possible, spark plugs should be tightened to the factory torquespecification. If a torque wrench is not available, and the plug youare installing is equipped with a crush washer, lighten the plug until the washer seats, then tighten it an additional 1/4 turn to crush the washer. 15. Apply a small amount of a silicone dielectric grease or Yamaha Allˇ Purpose Marine grease to the ribbed, ceramic portion of the spark plug lead and inside the spark plug boot to prevent sticking, then install the boot to the spark plug and push until it clicks into place. The click may be felt or heard. Gently pull back on the boot to assure proper contact. 16. If applicable, connect the negative battery cable or turn the battery switch ON. 17. Test run the outboard (using a test tank or flush fitting) and insure proper operation. READING SPARK PLUGS • See Figures 120 thru 125 Reading spark plugs can be avaluable tuning aid. By examining the insulator firing nose color, you can determine much about the engine's overall operating condition. In general, a light tan/gray color tells you that the spark plug is at the optimum temperature and that the engine is in good operating condition. Dark coloring, such as heavy black wet or dry deposits usually indicate a fouling problem. Heavy, dry deposits can indicate an overly rich condition, too cold a heat range spark plug, possible vacuum leak, low compression, overly retarded timing or too large a plug gap. If the deposits are wet, it can be an indication of a breached head gasket or an extremely rich condition, depending on what liquid is present at the firing tip. Also look for signs of detonation, such as silver specs, black specs or melting or breakage at the firing tip. Compare your plugs to the illustrations shown to identify the most common plug conditions. Fouled Spark Plugs A spark plug is '1ouled" when the insulator nose at the firing tip becomes coated with aforeign substance, such as fuel, oil or carbon. This coating makes it easier for the voltage to follow along the insulator nose and leach back down into the metal shell, grounding out, rather than bridging the gap normally. Fuel, oil and carbon fouling can all be caused by different things but in any case, once a spark plug is fouled, it will not provide voltage to the firing tip and that cylinder will not fire properly. In many cases, the spark plug cannot be cleaned sufficiently to restore normal operation. It istherefore recommended that fouled plugs be replaced. Signs of fouling or excessive heat must be traced quickly to prevent further deterioration of performance and to prevent possible engine damage. Overheated Spark Plugs When a spark plug tip shows signs of melting or is broken, it usually means that excessive heat andlor detonation was present in that particular combustion chamber or that the spark plug was suffering from thermal shock. Since spark plugs do not create heat by themselves, one must use this visual clue to track down the root cause of the problem. In any case, damaged firing tips most often indicate that cylinder pressures or temperatures were too high. Left unresolved, this condition usually results in more serious engine damage. Detonation refers to a type of abnormal combustion that is usually preceded by pre-ignition. It is most often caused by a hot spot formed in the combustion chamber. As air and fuel is drawn into the combustion chamber during the intake stroke, this hot spot will "pre-ignite" the air fuel mixture without any spark from the spark plugs. Detonation Detonation exerts a great deal of downward force on the pistons as they are being forced upward by the mechanical action of the connecting rods. When this occurs, the resulting concussion, shock waves and heat can be severe. Spark plug tips can be broken or melted and other internal engine components such as the pistons or connecting rods themselves can be damaged. Left unresolved, engine damage is almost certain to occur, with the spark plug usually suffering the first signs of damage. • When signs of detonation or pre-ignition are observed, they are symptom of another problem. You must determine and correct the situation that caused the hot spot to form in the first place. MAINTENANCE & TUNE-UP 2-37 Fig. 120 A normally worn spark plug should have light tan or gray deposits on the firing tip (electrode) Fig.123 An oil-fouled spark plug indicates a powerhead with worn piston rings or a malfunctioning oil injection system that allows excessive oil to enter the combustion chamber INSPECTION & GAPPING + See Figures 126 and 127 Fig. 121 A carbon-fouled plug, identified by soft, sooty black deposits, may indicate an improperly tuned powerhead Fig. 124 A physically damaged spark plug may be evidence of severe detonation in that cylinder. Watch the cylinder carefully between services, as a continued detonation will not only damage the plug but will most likely damage the powerhead ..SY A particular spark plug might m hundreds of powerheads and although the factory will typically set the gap to a pre-selected setting, this gap may not be the right one for your particular powerhead. Insufficient spark plug gap can cause pre-ignition, detonation, even engine damage. Too much gap can result in a higher rate of misfires, noticeable loss of power, plug fouling and poor economy. • Refer to the Tune-Up Specifications chart for spark plug gaps. Check spark plug gap before installation. The ground electrode (the Lshaped one connected to the body of the plug) must be parallel to the center electrode and the specified size wire gauge must pass between the electrodes with a slight drag. Do not use a flat feeler gauge when measuring the gap on a used plug, because the reading may be inaccurate. A round-wire type gapping tool is the best way to check the gap. The correct gauge should pass through the electrode gap with a slight drag. If you're in doubt, try a wire that is one size Fig. 122 This spark plug has been left in the powerhead too long, as evidenced by the extreme gap. Plugs with such an extreme gap can cause misfiring and stumbling accompanied by a noticeable lack of power Fig. 125 A bridged or almost bridged spark plug, identified by the build-up between the electrodes caused by excessive carbon or oil build up on the plug .. ,• . . 2-38 MAINTENANCE & TUNE-UP Fig. 127 Most plug gapping tools have an adjusting fitting used to bend the ground electrode smaller and one larger. The smaller gauge should go through easily, while the larger one shouldn't go through at all. Wire gapping tools usually have a bending tool attached. USE IT! This tool greatly reduces the chance of breaking off the electrode and is much more accurate. Never attempt to bend or move the center electrode. Also, be careful not to bend the side electrode too far or too often as it may weaken and break off within the engine. requiring removal of the cylinder head to retrieve it. Spark PI!JQ Wires TESTING Each time you remove the engine cover, visually inspect the spark plug wires for burns, cuts or breaks in the insulation. Check the boots on the coil and at the spark plug end. Replace any wire that is damaged. Once a year, usually when you change your spark plugs, check the resistance of the spark plug wires with an ohmmeter. Wires with excessive resistance will cause misfiring and may make the engine difficult to start. In addition worn wires will allow arcing and misfiring in humid conditions. Remove the spark plug wire from the engine. Test the wires by connecting one lead of the ohmmeter to the coil end of the wire and the other lead to the spark plug end of the wire. Resistance should measure approximately 7000 ohms per foot of wire. • Keep in mind that just because a spark plug wire passes a resistance test doesn't mean that it is in good shape. Cracked or deteriorated insulation will allow the circuit to misfire under load, especially when wet. Always visually check wires to cuts, cracks or breaks in the insulation. If found, run the engine in a test tank or on a flush device either at night (looking for a bluish glow from the wires that would indicate arcing) or while spraying water on them while listening for an engine stumble . Yamaha only publishes specifications for resistance of the spark plug caps used on the 80J.140 hp V4 motors. These models contain resistor caps on the ends of the spark plug leads, the caps should have 4000ˇ6000 ohms resistance. • Yamaha technical literature mentions that some other models (like the2 hp) use spark plug resistor caps, however we could not locate any testing specifications other than those listed above. Regardless of resistance tests and visual checks, it is never a bad idea to replace spark plug leads at least every couple of years, and to keep the old ones around lor spares. Think of spark plug wires as a relatively low cost item that whose replacement can also be considered maintenance. REMOVAL & INSTALLATION When installing a new set of spark plug wires, replace the wires one at a time so there will be no confusion. Coat the inside of the boots with a dielectric grease or Yamaha All-Purpose Marine grease to prevent sticking and corrosion. Install the boot firmly over the spark plug until it clicks into place. The click may be felt or heard. Gently pull back on the boot to assure proper contact. Repeat the process for each wire. • It is vitally important to route the new spark plug wire the same as the original and install it in a similar manner on the powerhead. Improper routing of spark plug wires may cause powerhead performance problems. Electronic (CDI/CDI Micro/TCI/TCI Micro) Ignition Systems INSPECTION + See Figure 128 TE Modern electronic ignition systems have become one of the most reliable components on an outboard. There is very little maintenance involved in the operation of these ignition systems and even less to repair if they fail. Most systems are sealed and there is no option other than to replace failed components. 1. Just as a tune-up is pointless on an engine with no compression, installing new spark plugs will not do much for an engine with a damaged ignition system. At each tune-up, visually inspect all ignition system components for signs of obvious defects. Look lor signs of burnt, cracked or broken insulation. Replace wires or components with obvious defects. If spark plug condition suggests weak or no spark on one or more cylinders, perform ignition system testing to eliminate possible worn or defective components. If trouble is suspected, it is very important to narrow down the problem to the ignition system and replace the correct components rather than just replace par1s hoping to solve the problem. Electronic components can be very expensive and are usually not returnable. Refer to the "Ignition and Electrical Systemsˇ section for more information on troubleshooting and repairing ignition systems. These days, all Yamaha outboards are equipped with some form of a Capacitor Discharge Ignition (COl) System or Transistor Controlled Ignition (TCI) which are very similar systems. The only possible adjustment on most CDifTCI systems would be timing (Idle, Garb Pickup and/or WOT) and that varies by engine/model. For more details, please refer to the Timing and Synchronization procedure for your motor. Various engines are equipped with the Yamaha Microcomputer Ignition System (YMIS) or the TCI Micro system. YMIS is essentially a standard COl type ignition with computer controls. The TCI Micro system is similar to the COl Micro/YMIS system. In both cases, there are normally no adjustable components in this system, but for more details on a particular engine, please refer to Timing and Synchronization in this section. Electrical System Checks ˇ CHECKING THE BATIERY Difficulty in starting accounts for almost half of the service required on boats each year. Some years ago, a survey by Champion Spark Plug Company indicated that roughly one third of all boat owners experienced a "won't start" condition in a given year. When an engine won't start, most people blame the battery when. in fact, it may be that the battery has run down in a futile attempt to start an engine with other problems. Maintaining your battery in peak condition may be though of as either tune-up or maintenance material. Most wise boaters will consider it to be both. A complete check up of the electrical system in yourboat at the beginning of the boating season is a wise move. Continued regular maintenance of the battery will ensure trouble free starting on the water. Details on battery service procedures are included under Batteries in Boat Maintenance. The following is a list of basic electrical system service procedures that should be performed as part of any tune-up. • Check the battery for solid cable connections • Check the battery and cables for signs of corrosion damage • Check the battery case for damage or electrolyte leakage • Check the electrolyte level in each cell • Check to be sure the battery is fastened securely in position • Check the battery's state of charge and charge as necessary • Check battery voltage while cranking the starter. Voltage should remain above 9.5 volts • Clean the battery, terminals and cables • Coat the battery terminals with dielectric grease or terminal protector CHECKING THE STARTER MOTOR + See Figure 129 The starter motor system generally includes the battery, starter motor, solenoid, ignition switch and in most cases, a relay. The frequency of starts governs how often the motor should be removed and reconditioned. The manufacturer recommends removal and overhaul every 1000 hours. When checking the starter motor circuit during a tune-up, ensure the battery has the proper rating and is fully charged. Many starter motors are needlessly overhauled, when the battery is actually the culprit. 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 9.5 volts or greater, and the starter motor fails to operate, repair or replace the starter motor. CHECKING THE INTERNAL WIRING HARNESS + See Figure 130 Corrosion is probably a boater's worst enemy. It is especially harmful to wiring harnesses and connectors. Small amounts of corrosion can cause havoc in an electrical system and make it appear as if major problems are present The following are a list of checks that should be performed as part of any tune-up. • Perform a through visual check of all wiring harnesses and connectors on the vessel • Check for frayed or chafed insulation, loose or corroded connections between wires and terminals • Unplug all suspect connectors and check terminal pins to be sure they are not bent or broken, then lubricate and protect all terminal pins with dielectric grease to provide a water tight seal • Check any suspect harness for continuity between the harness connection and terminal end. Repair any wire that shows no continuity (infinite resistance) MAINTENANCE & TUNE-UP 2-39 Fuel System Checks FUEL INSPECTION Most often, tune-ups are performed at the beginning of the boating season. If the fuel system in your boat was properly winterized, there should be no problem with starting the outboard for the first time in the spring. If problems exist, perform the following checks. 1. If the condition of the fuel is in doubt, drain, clean, and fill the tank with fresh fuel. 2. Visually check all fuel lines for kinks, leaks, deterioration or other damage. CAUTION We cannot over-emphasize how important It is to visually check the fuel lines and fittings lor any sign of leakage. This is even more important on the high-pressure fuel circuits of the EFI and especially the HPDI motors. It Is a good idea to prime the all fuel systems using the primer bulb and, on EFIIHPDI systems, check the llnes/flttlngs of the high-pressure fuel circuit alter the motor has been operated (meaning the system has been under normal operating pressures). 3. Disconnect the fuel lines and blow them out with compressed air to dislodge any contamination or other foreign material. 4. Check the line between the fuel pump and the carburetor (or the vapor separator tank on fuel injected motors) while the powerhead is operating and the line between the fuel tank and the pump when the powerhead is not operating. A leak between the tank and the pump many times will not appear when the powerhead is operating, because the suction created by the pump drawing fuel will not allow the fuel to leak. Once the powerhead is shut down and the suction no longer exists, fuel may begin to leak. DO NOT do anything around the fuel system without first reviewing the warnings and safety precautions in the Fuel System section. Remember that fuel is highly combustible and all potential sources of ignition from cigarettes and open flame tosparks must be kept far away from the work area. + See Figure 131 ALL Yamaha motors use a low-pressure fuel pump to draw fuel from a boat mounted or portable fuel tank and feed either the carburetor float bowls or fuel vapor separator tank of fuel injected motors. The low-pressure pumps Fig. 128 Typical Yamaha Ignition control unit, used on models equipped with the COl Micro (YMIS) system Fig. 129 Functional diagram of a typical cranking circuit Fig. 130Any time electrical gremlins are present, always check the harness connectors for pins which are bent, broken or corroded 2ˇ40 MAINTENANCE & TUNE-UP . ... .. . . . . .. Fig. 131 Arrangement of the vacuum operated fuel pump parts. A tiny hole in the diaphragm can affect fuel pump performance operate in virtually the same manner for all Yamaha motors, using a displacement-diaphragm design to alternately create a vacuum in the line from the fuel tank and generate pressure in the line going to the float bowl or vapor separator. On carbureted motors, if the powerhead operates as if the load on the boat is being constantly increased and decreased, even though an attempt is being made to hold a constant powerhead speed, the problem can most likely be attributed to the fuel pump. Many times, a defective fuel pump diaphragm is mistakenly diagnosed as a problem in the ignition system. The most common problem is a tiny pinhole in the diaphragm or a bent check valve inside the fuel pump. Such a small hole will permit gas to enter the crankcase and wet foul the spark plug at idle-speed. During high-speed operation, gas quantity is limited, the plug is not fouled 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 or the vapor separator tank. This lack of fuel will cause the engine to run lean, lose rpm or possibly even contribute to piston scoring. Pressure Check cŽM>+ See Figures 132 and 133 • If an Integral fuel pump carburetor is installed, the fuel pressure cannot be checked. 1. Mount the outboard unit in a test tank, or on the boat in a body of water. BumHole Fig. 133 Lack of adequate fuel, possibly caused by a defective fuel pump, caused the hole burned Into the top of this piston • Remember, the powerhead will not start without the emergency tetherin place behind the kill switch knob. Water must circulate through the lower unit to the engine any time the Never operate theengine at high speed with a flush device attached. The engine, operating at high speed with such a device attached, would runaway from lack of a load on the propeller, causing extensive damage. 2. Install the fuel pressure gauge in the fuel line between the fuel pump and the carburetor or the vapor separator tank. 3.Start the engine and check the fuel pressure. FUEL OUTLET HOSE HOSE PRESSURE RESTR ICTOR . ...... ... : .. 7u: (OR VAPOR SEPARATOR) Fig. 132 Test setup to check fuel pump pressure engine is run to prevent damage to the water pump in the lower unit. Just five seconds without water will damage the water pump. 4. Operate the powerhead at full throttle and check the pressure reading. The gauge should indicate at least 2 psi {14 kPa). HIGH-PRESSURE FUEL PUMP INSPECTION In addition to the all important visual inspection of the fuel system lines and fittings on outboards with fuel injection a quick check of the high pressure fuel circuits will verify the ability of the system to operate properly. This check should be performed with each tune-up or at least annually at the beginning of the season. Pressure Check TE EFI engines utilize a 2-stage fuel system, the low-pressure circuit (fuel tank-toˇpump and pump-to-vapor separator), as well as a high-pressure circuit (vapor separator-to-fuel injectors). HPOI engines actually use a 3 stage fuel system, low-pressure (fuel tankto- pump and pump-to-vapor separator), a first stage high-pressure (or medium pressure circuit, vapor separator-to-mechanical high-pressure pump) and second stage high-pressure (extreme high-pressure circuit, highpressure pump-to-fuel injectors). The low-pressure circuit of all fuel-injected motors works in the same manner as the low-pressure circuit used on carbureted models. The high-pressure circuit of all fuel injected Yamaha motors works in a similar fashion using a submerged electric fuel pump located within the vapor separator tank to achieve fuel pressure somewhere in the 30-40 psi (207278 kPa) range depending upon the year and model. Most models are equipped with a fuel test port on the top of the separator tank, but there are exceptions where the port is remote mounted. The extreme high-pressure circuit of HPDI engines takes this already high-pressure fuel and achieves operating pressures up to 1000 psi (6895 kPa) on some direct injection motors. EF1 Motors + See Figure 134 1. Locate the fuel pressure check valve/test fitting on the motor. In most cases it will be a Schrader type valve fitting located on the top of the vapor separator tank (under a protective cap). 2. Remove the protective cap from the pressure test fitting, then cover the fitting with a clean, dry shop rag (to protect against possible fuel spray) and connect a fuel pressure gauge to the test fitting/check valve. 3. Provide a source of cooling water (using a test tank or flush fitting) and start the engine, allowing it to run at idle for about a minute. Observe and record the fuel pressure indicated on the gauge. 4. The fuel pressure should be 35.6 psi (250 kPa) for OX66 motors. 5. Shut the engine off and, making sure a shop rag is in place to catch any escaping fuel spray, carefully disconnect the gauge. 6. If fuel pressure is below specification, refer to the Fuel System section for further diagnosis. HPDI Motors + See Figures 134 and 135 1. Remove the protective cap form the fuel pressure check valve/test fitting (a Schrader type valve fitting located on the top of the vapor separator tank). Fuel Pressure Gauge Fig. 134 On most motors the high-pressure fuel circuit is checked using a test fitting on top of the vapor separator tank MAINTENANCE & TUNE-UP 2-41 2. Cover the fitting with a clean, dry shop rag (to protect against possible fuel spray) and connect a fuel pressure gauge to the test fitting/check valve. 3. For 225/250 hp V6 engines, turn the ignition switch ON (w..hout starting the motor) and observe the pressure. W..hin 5 seconds the electric pump should run generating a line pressure of about 50.8 psi (350 kPa), but then pressure should lower slightly to about 43.5 psi (300 kPa). 4. Provide a source of cooling water (using a test tank or flush fitting) and start the engine, allowing it to run at idle for about a minute (on 225/250 hp motors, run the engine for about 5 minutes). Observe and record the fuel pressure indicated on the gauge. 5. Shut the engine off and, making sure a shop rag is in place to catch any escaping fuel spray, carefully disconnect the gauge. 6. The first stage high-pressure (medium pressure for these HPDI motors) fuel circuit should generate about 39.8-51.2 psi (280-360 kPa) while the engine is running on all except the 225/250 hp motors, on which pressure must be at least 50.8 psi (350 kPa). 7. If fuel pressure is below specification, refer to the Fuel System section for further diagnosis. 8. To check the extreme-high pressure circuit (2nd stage high-pressure fuel circuit) on 150-200 hp motors, proceed as follows: a. Remo..e the flywheel cover for access. b. Locate and disconnect the fuel pressure sensor wiring harness (it's mounted on the mechanical fuel pump assembly). c. Install the Yamaha 3-pin test harness (#YB-06769) or fabricate a test harness using 3 jumper leads to reconnect the pins in the disconnected harness. The key to fabricating a test harness is to make sure you can safely connect the 3 sets of pins without them shorting to each other or ground AND making sure that you can safely probe the sensor output voltage using a DVOM. d. Using the source of cooling water, start and run the engine at idle speed. e. Measure the fuel pressure sensor output voltage across the Pink and Black wires, it should be 2.8-3.2 volts. If voltage is as specified the sensor circuit and the extreme high-pressure fuel circuit should both be operating within the required specification (however, keep in mind that a malfunctioning sensor could, in theory, hide a malfunctioning fuel circuit). 9. Once the test is completed, reconnect the wiring harness and install the flywheel cover. Checking/Changing HPDI Pump Gear Oil + See Figures 136, 137 and 138 The extreme-high pressure fuel circuit of the HPDI system is feed by a beltˇdriven, mechanical fuel pump. The pump contains a reservoir of gear oil for internal lubrication. Although the pump requires VERY little maintenance, you should check the gear oil level, at least annually, with the pre-season tune-up. Checking pump gear oil is a very straightforward procedure. For access you'll have to remove the flywheel cover. Once exposed, follow the drive belt Fig. 135 On 150.200 hp HPDI motors you can check the extreme high pressure fuel circuit by monitoring fuel pressure sensor output voltage 2-42 MAINTENANCE & TUNE-UP Check Bolt Fig. 136 The HPDI mechanical fuel pump uses a built-in oil reservoir with drain (1) and level check (2) plugs •225/250 hp model shown (others similar) Fig. 137 On 15D-200 hp models the pump gear oil level should beabout 0.51 ln. (13mm) below the top of the pump body Fig. 138 This drawing shows the oil level, just even with the bottom of the check plug bore on 2251250 hp motors from the crankshaft pulley found just above the flywheel to the fuel pump's driven gear. Next, look down the side of the pump body, there will be two slotted-head (and/or hex-head) screws on the pump body. The upper one is for fluid level, the lower one is for draining Carefully loosen and remove the upper plug. If properly filled, oil will start to run out of the plug. If not, stick a thin tool (such as a screwdriver or Allen key) into the hole to check the level. If necessary, add a small amount of SAE 90W gearcase lubricant to top off the system and install the fluid level check bolt. • On 150-200 hp motors the proper fluid level is measured as approximately 0.51 ln. (13mm) below the surface of the mechanical fuel pump body and the cover. This measurement places the level almost dead center on the level checking screw. About every 5 years or thousand hours of operation you should change the pump gear oil. This is done by first removing the upper (fluid level/check) plug (because you never remove a drain plug until the level plug has at least been loosened to ensure you'll be able to refill the reservoir. Then, place a small drain pan or funnel/drain tube leading to a drain pan under the lower (drain) plug. Remove the drain plug from the pump body and allow the gear oil to completely drain. The recommended method of refilling the fuel pump is to squeeze or pump fresh gear oil in through the drain plug until gear oil starts to run out of the level/check plug. Install the check plug, squeeze in a tiny bit more (to make up for what will run out while you're installing the drain plug) and finally, install the drain plug securely to the pump body. After checking or changing the pump gear oil, wipe away all traces of oil using a clean shop rag and operate the powerhead, then check the surfaces around the plugs again to make sure there is no leakage. Checking the HPDI Drive Belt + See Figure 139 A drive belt is used to operate mechanical fuel pump which powers the HPDI extreme high-pressure fuel circuit. The belt, driven off a crankshaft mounted pulley (found just above the flywheel) runs around the pump pulley and is secured using a tensioner pulley. The toothed belt is similar in design and use to that of a timing belt and should therefore be subject to the same level of checking and scrutiny. At least once a season (preferably at the pre-season tune-up) remove the flywheel cover and visually inspect the belt for signs of excessive wear or damage. Regardless of visual inspection, be sure to replace the belt after 1ooo hours or 5 years of service. Keep in mind that the belt is necessary to operate the fuel system, so failure will keep the motor from running, potentially stranding the craft. For more details on belt service, please refer to the Fuel System section. Outside Fig. 139 At least once a year, visually check the inside and outside of the HPDI fuel pump drive belt for wear or damage . CHECKING/CLEANING THE CARBURETORS OR THROTILE BODIES Visually inspect the carburetors or throttle bodies at each tune-up. Make sure there are no signs of gunk in the throttle bores. The throttle valves should move smoothly without sticking or binding. Linkage points should be lubricated as necessary. Periodic carburetor adjustments are usually not necessary, as long as the outboard is running correctly. As a matter of fact, in recent service literature Yamaha finally came out and stated that •carburetor adjustments are not necessary on a properly operating motor" so they've finally admitted what we knew all along, "if it ain't broke, don't fix it: When ij does come time for carburetor adjustments the mixture screw (when equipped) does not usually require adjustment unless the motor has been moved to/from altitude. The timing and synchronization adjustments are covered elsewhere in this section and should at least be checked annually, even if not actual adjustment is made to the linkages. • Many carburetor adjustments require that the outboard unit is running in a test tank or with the boat in a body of water (and a helper to navigate the craft). For maximum performance, the idle rpm and other carburetor adjustments should be made under actual operating (load) conditions. Idle Speed Adjustment (Minor Adjustments) • The engine idle speed is normally computer controlled on EFI/HPDI motors, no adjustments are necessary or possible. For more details, please refer to Timing and Synchronization in this section or the information on fuel injection found in the Fuel System section. Although the full timing and synchronization adjustments should be checked at each tune-up, idle speed can be adjusted independently on carbureted models using the carburetor throttle stop screw which physically determines the positioning of the throttle plate. When the screw is turned one direction (usually clockwise) the throttle plate is held open more, increasing idle speed. When the screw is turned in the opposite direction (normally counterclockwise) the plate is allowed to close further, lowering idle speed. • Don't rely on the boat mounted tachometer when setting idle speed, use a high quality shop tachometer to ensure accurate readings. For more details on tachometers refer to the information under Timing and Synchronization. IDLE SPEED ADJUSTMENT • See Figures 140 thru 143 • Remember, the powerhead should not start without the emergency tether in place behind the kill switch knob. Fig. 140 Location of the throttle stop screw typically found on 2-cyllnder powerheads MAINTENANCE & TUNE-UP 2-43 / '" 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. Never operate the engine at high speed with a flush device attached. The engine, operating at high speed with such a device attached, would runaway from lack of a load on the propeller, causing extensive damage. • The 2 hp model has only one carburetor adjustment screw -the idle speed screw on the starboard side of the carburetor. This screw controls the amount of air entering the powerhead instead of fuel. The idle speed is regulated by the throttle stop screw. The screw sets the position of the throttle plate inside the carburetor throat. • For additional information on your engine/carburetor, please refer to the Timing and Synchronization section and the Fuel System section. 1. Remove the cowling and attach a tachometer. 2. Start the engine and allow it to warm to operating temperature. 3. Note the idle speed on thetachometer. If the idle speed is not within specification, rotate the idle speed screw until the idle speed falls within specification. The idle speed specification is noted in the Tune-Up Specifications chart. 4. Rotating the idle speed screw clockwise increases powerhead speed, and rotating the screw counterclockwise decreases powerhead speed. Fig. 142 location of the throttle stop screw all other 3-cyllnder powerheads except the 25/30 hp Fig. 143 The idle speed is regulated by the throttle stop screw which sets the position of the throttle plate inside the carburetor throat -typical V4 and V6 powerheads 2ˇ44 MAINTENANCE & TUNE-UP TIMING AND SYNCHRONIZATION General Information Anytime the fuel system or the ignition system on a powerhead is serviced to replacea faultypart or any adjustments are made for any reason, powerhead timing and synchronization mustbecarefullycheckedand verified. Depending on the engine (predominantly on carbureted motors without microcomputer controls), adjustment of the timing and synchronization can be extremely important to obtain maximum efficiency. The powerhead cannot perform properly and produce its designed horsepower output if the fuel and ignition systems have not been precisely adjusted. We say, depending on the engine because some of the models covered by this manual are equipped with a single carburetor or a computer controlled system (including the EFIIHPDI motors) which requires few, if anyperiodic adjustments once installed and properly set-up. As a matter of fact, because of the EPA regulated carburetors used on mostof the later model Yamahas, very few adjustments are possible on most carburetors. Periodic mixture adjustments should not be necessary. However, any carburetor will requireinitial set-up and adjustment alter disassembly or rebuilding. Also, any motor equipped with multiple carburetors will require synchronization witheach other alter the carburetors have been removed or separated. The multiple throttfe valves used on EFVHPDI motors normally require some form of synchronization as well if they are removed or the linkage is disconnected for some other reason. Although some of the motors covered by this manual utilize fully electronically controlled ignition and timing systems, most of themotors allow for SOME form of timing adjustment. Care should be taken to ensure settings are correct during each tune-up. • Before making any adjustments to the ignition timing or synchronizing the ignition to the fuel system, both systems should be verified to be in good working order. Timing All outboard powerheads have some type of synchronization between the fuel and ignition systems. Many of the Yamahas covered here, except those equipped with a micro-computer controlled for the TCI/CDI systems or the EFIIHPDI systems, are equipped with a mechanical advance type Capacitor Discharge Ignition (COl) system and use a series of linkrods between the carburetor and the ignition base plate assembly.At the time the throttleis opened, the ignition base plate assembly is rotated by means of the link rod, thus advancing the timing. On models equipped with amicro-computer, the control module decides when to advance or retard the timing, based on input from various sensors (usually a crankshaft position sensor). Therefore, there is no link rod between the magneto control lever and the stator assembly. Many models have timingmarkson the flywheel and COl base. A timing light is normally used to check the ignition timing dynamicallyˇwith the powerheadoperating. An alternate method is to check the static timing ˇwith thepowerhead not operating. This second method requires the useof a dial indicatorgauge. Various models have unique methods of checking ignition timing. These differences are explained in detail later in this section. Synchronization In sifr4)1e terms, synchronization is timing the carburetion or throttle valves to theigni tion (and to each other).As the throttle is advanced to increase powerhead rpm, the carburetorl1hrottle valve and the ignition systems are both advanced equally and at the same rate. Any time the fuel system or the ignition system on a powerhead is serviced to replace a fauHy part or any adjustments are made for any reason, powerhead timing and synchronization must be carefully checked and verified. For this reason the timing and synchronizing procedures have been separated from all others and presented alone in this section. Before making adjustments with the timing or synchronizing, the ignition system should be thoroughlychecked and thefuel system verified to be in good working order. Prepping the Motor for Timing and Synchronization Timing and synchronizing the ignition and fuel systems on an outboard motorare critical adjustments. The following equipment is essential and is called out repeatedly in this section. This equipment must be used as described, unless otherwise instructed by the equipment manufacturer. Naturally, the equipmentis removed following completion of the adjustments. For many of the adjustments, the manufacturer recommends the use of a test propeller instead of the normal propeller in order to put a spec..ic load on the engine and propeller shaft. The use of the test propeller prevents the engine from excessive rpm while applying a load of pre-set value. • Dial Indicator ˇTop dead center (TDC) of the No. 1 (top) piston must be precisely known before the timing adjustment can bemade on many models. TDC can only be determined through installation of a dial indicator into the No. 1 spark plug opening. • Timing Light • During many procedures in this section, the timing mark on the flywheel must be aligned with a stationary timing mark on the engine while the powerhead is being cranked or is running. Only through use of a timing lighl connected to the No. 1 spark plug lead, can the timing mark on theflywheel beobserved while the engine is operating. • TachometerˇA tachomeler connected to the powerhead must be used to accurately determine engine speed during idle and high-speed adjustment. Engine speed readings rangefrom about 0ˇ6.000 rpm in increments of 100 rpm. Choose a tachometer with solidstate electronic circuits which eliminates the need for relays or batteries and contribute to their accuracy. For maximum performance, the idle rpm should be adjusted under actual operating conditions. Undersuch conditionsit might be necessary to attach a tachometer closer to the powerhead than the one installedon the control panel. • An auxiliary tachometer can be connected by attaching it to the tachometer leads in the control panel. These leads are usually Black and Green. Connect the Black lead to the ground terminal of the auxiliarr, tachometer and the Green lead to the input or hot terminal of the auxiliary tachometer. • Flywheel Rotation ˇThe instructions may call for rotating the flywheel until certain marks are aligned with the timing pointer. When the flywheel must be rotated, always move the flywheel in the indicated direction (the normal directionof rotation, normally clockwise, but if in doubt you can always double-check by bumping the motor gently using the starter). If the flywheel should be rotated in the opposite direction, the water pump impeller vaneswould be twisted. Should the powerhead be started with the pump tangsbent back in the wrong direction, the tangs may not have time to bend inthe correct direction before they are damaged. The least amount of damagetothe water pump will affect cooling of the powerhead • Test Tank • Since the engine must be operated at various times and engine speeds during some procedures, a test tank or moving the boat into a bodyof water, is necessary. If installing the enginein a test tank, outfit the engine with an appropriate test propeller Water must circulate through the lowerunit to the powerhead anytime the powerhead Is operating to prevent damage to the water pump in the lower unit. Just a few secondswithout water will damage the water pump Impeller. • Remember the powerhead should not start without the emergency tether in place behind the kill switch knob. Never operate the powerhead above a fast idle with a flush attachment connected to the lower unit. Operating the powerhead at a high rpm with no load on the propeller shaft could cause the powerhead to runaway causing extensive damage to the unit. . • Many adjustment procedures involve checking for proper operation BEFORE touching the current settings. In these cases, remember that no adjustment is necessary if the motor passes the checking portion of the procedure. TACHOMETER CONNECTIONS + See Figures 144 and 145 A tachometer is installed as standard equipment in the dash of many boats. However these tachometers are normally not easy to read when working on the motor and they are normally not labeled as accurately as a shop tachometer. II adjustments need to be made with the outboard running it is usually necessary to attach a tachometer closer to the powerhead than the one installed on the control panel. Many olthe outboards covered in this manual use a CDI system firing a twin lead ignition coil twice for each crankshaft revolution. II an induction tachometer is installed to measure powerhead speed, the tachometer will probably indicate double the actual crankshaft rotation. 1. On manual start models except the 2 hp model, connect the two tachometer leads to the two green leads from the stator. Either tachometer lead may be connected to either green lead. 2. On electric start models, open the remote control box. Locate the Black and Green leads or on models equipped with a tachometer, disconnect the Black and Green leads from the tachometer. Connect the Black lead to the ground terminal of the auxiliary tachometer and the Green lead to the input or hot terminal of the auxiliary tachometer. 3. On the 2 hp model, connect the positive tachometer lead to the primary negative terminal of the coil (usually a small black lead), and the negative tachometer lead to a suitable ground. 4. II a tachometer is purchased from Yamaha or another manufacturer, it should be calibrated for the model matching the particular model powerhead. Remove the rubber plug from the back of the meter. Observe the ring with 4P, 6P, and 12P embossed around the ring. These numbers indicate the number of possible poles used on the flywheel magnetos. Determine the number of poles on the flywheel (refer to the Tune-Up Specifications chart in this section) and using a slotted screwdriver, move the arrow until it points toward the desired pole setting. 2 Hp Model IGNITION TIMING The ignition system on these models provides automatic ignition advance. Ignition timing is not adjustable . MAINTENANCE & TUNE-UP 2-45 IDLE SPEED + See Figure 146 1. Mount the engine in a test tank or move the boat to a body of water. 2. If necessary, remove cowling and connect a tachometer to the powerhead. • The Idle speed adjustment screw extends through the front of the engine cowling, however It may be necessary to remove the sides of the cowling in order to attach the tachometer. 3. Start the engine and allow it to reach operating temperature. 4. Check idle speed. The powerhead should idle at the specified rpm in the Tune-up Specifications chart. 5. If adjustment is necessary, rotate the idle adjustment screw until the powerhead idles at the required rpm. Generally, turning the screw IN will raise the idle speed, while turning the screw OUT will lower the idle speed. 6. Stop the engine and remove the tachometer. 3 Hp Model IDLE SPEED .Ž. + See Figures 147 and 148 1. Mount the engine in a test tank or move the boat to a body of water. 2. Remove the cowling and connect a tachometer to the powerhead. 3. Turn the pilot screw in until it lightly seats and then back out the specified number of turns, as indicated in the Carburetor Set-Up Specifications chart, found in the Fuel System section. 4. Start the engine and allow it to warm to operating temperature. 5. Check engine speed at idle. The powerhead should idle at the rpm specified in the Tune-up Specifications chart. 6. Place the engine in gear and check engine trolling speed in the same manner. 7. If adjustment is necessary, rotate the idle speed adjustment screw (not the pilot screw) until the powerhead idles at the required rpm. Normally, turning the screw IN will raise the idle speed, while turning the screw OUT will lower the idle speed. 8. Check and adjust the Ignition Timing, as detailed in this section. Fig. 144 Two green lighting coil leads are located inside a sheath on the powerhead. One or more of these leads may be used to connect a tachometer to the powerhead Fig. 145 Setting a tachometer for the correct calibration Fig. 146 1dle speed adjustment on 2 hp models 2-46 MAINTENANCE & TUNE-UP IGNITION TIMING + See Figure 149 .Ž ..sY The ignition system on these models provides automatic ign..ion advance. Ignition timing is not adjustable, however it should still be checked periodically to ensure the system is operating properly. 1. Check the idle speed and adjust as necessary. 2. In addition to the tachometer already installed for idle speed adjustment, connect a timing light to the spark plug lead. Remember, the motor MUST be operated in a test tank or with the boat launched in a body of water allowing it to run under load when running above idle. Failure to heed this waming will likely result in damage to the motor from over-speeding which will occur when the motor is raised toward WOTwithout a proper load on the propshaft. 3. Aim the timing light at the timing windows (located on the side of the flywheel housing). If the timing mark can be seen through the left window at idle and the right window at full throttle, the timing is correct. 4. liming cannot be adjusted. If timing is incorrect, a fault has occurred in the COl system. 5. Stop the engine and remove the tachometer and timing light. CHECKING/ADJUSTING THE THROffiE CABLE .osY With the throttle grip in the fully closed position, the throttle lever on the carburetor should also be in the fully closed position. If necessary, loosen the inner cable screw and adjust the inner cable to the proper length in order to allow both positions to just fully close; then tighten the cable screw. Turn the throttle grip making sure the throttle lever moves to the fully opened position and then returns to the fully closed position. 4 5 Hp (83 and 103cc) Models IDLE SPEED .Ž+ See Figures 150and 151 1. Mount the engine in a test tank or move the boat to a body of water. 2. Remove the cowling and connect a tachometer to the powerhead. 3. Turn the pilot screw (the vertical screw on top of the carburetor body) in until it lightly seats and then back out the specified number of !urns, as indicated in the Carburetor SetˇUp Specifications chart, found in the Fuel System section. 4. Start the engine and allow it to warm to operating temperature. Fig. 147 The pilot screw Is located in a horizontal position on the carburetor Fig. 148 The Idle speed screw Is located In a vertical position on the carburetor Fig. 149 The timing Is correct if the timing mali< can be seen through the left window at idle and the right window at full throttle Fig. 150 Thepilot screw Is located in a vertical position on top of the carburetor Fig. 151 The Idle speed screw is located in a horizontal position contacting the throttle lever 6t8 Hp Models IDLE SPEED MAINTENANCE & TUNE-UP 2-47 5. Check engine speed at idle. The powerhead should idle at the rpm specified in the Tune-up Specifications chart. 6. Place the engine in gear and check engine trolling speed in the same manner. 7. If adjustment is necessary, rotate the idle adjustment screw (the horizontal screw that contacts the throttle lever, not the pilot screw) until the powerhead idles at the required rpm. Turn the screw inward to increase idle speed or outward to decrease idle speed. IGNITION TIMING + See Figure 152 The ignition system on these models provides automatic ignition advance. Ignition timing is not adjustable. However, ignition timing should be checked periodically to ensure proper powerhead operation. 1. Check the idle speed and adjust as necessary. 2. In addition to the tachometer already installed for idle speed adjustment, connect a timing light to the spark plug lead. 3. Start and run the engine, making sure it is fully warmed. 4. Place the engine in gear. Remember, the motor MUST be operated in a test tank or with the boat launched in a body of water allowing it to run under load when running above idle. Failure to heed this warning will likely result in damage to the motor from over-speeding which will occur when the motor Is raised toward WOT without a proper load on the propshaft. 5. Aim the timing light at the timing windows. If the timing mark can be seen through the left window at with the powerhead operating between 1150 and 1700 rpm and the right window at 4500 rpm or more, the timing is correct. 6. Timing cannot be adjusted. If timing is incorrect, a fault has occurred in the CDI system. THROTILE LINKAGE ADJUSTMENT • See Figure 153 1. The engine idle speed must be properly adjusted before attempting of adjust the throttle linkage. If not already done, follow the steps under Idle Speed, in this section, before proceeding. 2. Remove the air intake silencer cover so you can clea..y see the carburetor throttle lever. 3. With the powerhead not operating, rotate the throttle grip back and forth between the idle and Wide-Open Throttle (WOT) position a couple of times. 4. Slowly rotate the grip to WOT, watching when the throttle lever on the carburetor contacts the WOT stopper. You want the lever to come in contact with the stopper just as the twist grip reaches with WOT position. 5. If it does not operate as desired, adjust the cable by first loosening the throttle cable lock screw (on the throttle lever) and then carefully pulling the cable out of the lever. 6. Turn the throttle grip to the SLOW (idle) position, then insert the inner wire into the hole in the throttle lever and lock it with the screw. 7. Next, pull out the outer wire and hook it onto the wire hook on the carburetor. 8. Check adjustment by again rotating the grip back and forth from idle to WOT a few times. Again, watch the throttle lever making sure it contacts the stopper just as the both the throttle valve and hand grip takes the WOT position. 9. Once the adjustment is satisfactory, install the air intake silencer cover and the cowling. 1. Mount the engine in a test tank or move the boat to a body of water. 2. Remove the cowling and connect a tachometer to the No. 1 cylinder spark plug lead. 3. Turn the pilot screw (the horizontal screw threaded into the side of the carburetor body) until it lightly seats and then back out the specified number of turns, as indicated in the Carburetor Set-Up Specifications chart, found in the Fuel System section. 4. Start the engine and allow it to warm to operating temperature. 5. Check engine speed at idle. The powerhead should idle at the rpm specified in the Tune-up Specifications chart. 6. Place the engine in gear and check engine trolling speed in the same manner. 7. If adjustment is necessary, rotate the idle adjustment screw (the vertical screw that contacts the carburetor throttle lever, not the pilot screw) until the powerhead idles at the required rpm. Turn the screw inward to increase idle speed or outward to decrease idle speed. 8. Check and, if necessary, adjust the Ignition Timing, as detailed in this section. Fig. 152 View through the window showing the timing mark on the Fig. 153 Loosening the screw on the barrel retaining end of the flywheel throttle cable . : .:: : 2-48 MAINTENANCE & TUNE-UP IGNITION TIMING • See Figures 154, 155 and 156 ..ODERATE The manufacturer provides a Static Timing Check/Adjustment procedure which can be performed without the use of a tachometer or timing light, but which requires the use of a Top Dead Center gauge or dial gauge which can be used to determine the top of piston travel. Alternately, we've also provided a Dynamic Timing Check/Adjustment procedure which we've found is also effective (and is preferred by some techs). Static Timing Check/Adjustment 1. Remove the engine cowling for access. 2. Disconnect the link rod between the COl magneto base and the magneto control lever at the ball joint. 3. Slowly rotate the flywheel clockwise by hand to align the timing plate with the 35 degree BTDC mark on the flywheel indicator. 4. Align the marks on the magneto base and the flywheel by turning the magneto base. Make sure the magneto base contacts the vertical pointer (stopper plate). 5. If adjustment is necessary, remove both spark plugs and install a dial gauge or TDC indicator in to the hole of the No. 1 (top) cylinder. 6. Slowly turn the flywheel clockwise by hand until the No. 1 piston comes up to TDC (the highest point of travel as indicated by the dial gauge). 7. Set the timing plate to TDC. 8. Next, turn the flywheel to align the timing plate with the 35 degree BTDC mark on the flywheel indicator. 9. Loosen the vertical pointer (stopper plate) set bolt, then align the marks on the magneto base and flywheel by turning the magneto base. 10. Adjust the vertical pointer {stopper plate) so it is in contact with the magneto base stopper {press the stopper plate against the full-advanced side of the magneto base). 11. T..ghten the vertical pointer (stopper plate) bolt and reconnect the link rod. Dynamic Check/Adjustment 1. Check the idle speed and adjust as necessary. 2. In addition to the tachometer already installed tor idle speed adjustment, connect a timing light to the spark plug lead. 3. Disconnect the link rod between the COl magneto base and the magneto control lever at the ball joint. • This link rod will remain disconnected until all adjustments have been completed. 4. Start the engine and allow it to reach operating temperature. Rotate the COl magneto base counterclockwise until the base stopper on the left contacts the vertical timing pointer. This is the full-advanced position. Remember, the motor MUST be operated in a test tank or with the boat launched In a body of water allowing it to run under load when running above idle. Failure to heed this warning will likely result in damage to the motor from over-speeding which will occur when the motor is raised toward WOT without a proper load on the propshaft. 5. Aim the timing light at the vertical timing pointer. The pointer should align between the 34 and 36° BTDC embossed marks on the flywheel edge. 6. If the pointer does not align, as described, loosen the bolt on the vertical pointer bracket and move the pointer and the stopper on the magneto base plate together, until the vertical pointer is properly aligned. Hold the magneto base plate and the pointer together with the pointer on the mark and tighten the bolt. 7. Shut down the powerhead. THROTILE LINKAGE ADJUSTMENT • See Figure 157 To check the throttle linkage adjustment set the shift lever in the fullˇ forward position and fully open the throttle grip. Check that the magneto base stopper is fully in contact with the vertical pointer (stopper plate) and the throttle valve is fully opened. Ifadjustment is necessary, proceed as follows: 1. Disconnect the link rod between the COl magneto base and the magneto control lever at the ball joint. 2. Set the shifter lever to the forward position and manually bring the stopper on the full-advanced side of the magneto base to contact the magneto base stopper. 3. Fully open the throttle grip, then loosen the locknut and turn the cable adjuster on the throttle "pull" cable (the outer of the 2 cables, which as the name suggests is used to pull the throttle open} until the carburetor throttle valve is fully opened. Then tighten the locknut for the throttle "pulr cable. 4. Now, loosen the locknut on the "push" throttle cable (the inner of the 2 cables, which is used to close the throttle valve) until there is about 0.12 in. (3mm) free-play on the throttle grip. Then tighten the locknut for the "push" cable. 5. Finally, adjust the magneto link rod so that the control lever comes into contact with the magneto base. Make sure the link rod is centered over the ball joint on the control lever, then carefully reconnect the link. 6. Verify that the throttle valve is in the fully opened position. Fig. 154 Make sure the link rod remains disconnected until all adjustments have been completed Fig. 155 A timing light Is needed for a dynamic check Fig. 156 The full-advanced position is achieved when the magneto base Is rotated counterclockwise until the stopper contacts the vertical timing pointer MAINTENANCE & TUNE-UP 2-49 Fig. 157 Throttle linkage components-6/8 hp models 9.9/15 Hp Models Link Joint Mark Magneto Control Lever Fig. 159 To adjust the timing, start by loosening the locknut and disconnecting the linkjoint. •. IGNITION TIMING • See Figures 158 thru 161 The complete timing check and adjustment procedure takes place with the engine NOT running. The good news is that means you won't need a tachometer or timing light, and nor will you need to mount it in a test tank or launch the boat. The bad news is that you WILL need a dial gauge. Ok, maybe that's not a bad thing cause you'll be able to do other things with it, likecheck rotor run-out on the tow vehicle (or on the crankshaft if you ever rebuild the powerhead). 1. Remove the cowling for access and locate the timing marks on the flywheel and the pointer on the starter housing. 2. Slowly turn the flywheel in the normal direction of rotation (clockwise) until the timing mark for WOT operation (refer to the Tune-Up Specifications chart in this section) aligns with the pointer on the starter cover. 3. Turn the magneto control lever so it contacts the WOT stopper, then check the link joint timing indicator to make sure it aligns with the flywheel mark. If it does, timing is properly set and no adjustment is necessary, you canstop here. If not. continue the procedure to properly adjust/set the ignition timing. 4. loosen the locknut on the link joint, then disconnect the link joint from the magneto control lever. 5. Remove the spark plug from the No. 1 (top) cylinder and install a dial gauge to determine TDC. Slowly turn the flywheel clockwise by hand until the piston reaches TDC. The dial indicator will increase in value until TDC is reached, then as the piston reverses direction it will begin to decrease again. Withthe piston at TDC zero the dial gauge. 6. Rotate the flywheel counterclockwise (yes, this is one of the few times we'll ever tell you to do that, but do it SLOWLY) until the dial gauge indicate the piston is 0.166 in. (4.2.2mm) Before Top Dead Center (BTDC). 7. At this point, turn the magneto control lever so that it contacts the WOT stopper. Now adjust the link joint length until the link joint timing indicator aligns with the flywheel mark and tighten the locknut. 8. Now check the idle timing adjustment by turning the flywheel CLOCKWISE (again, slowly) until the idle timing mark (not the WOT mark) aligns with the cover pointer. In this position, rotate the magneto lever to that Cover Timing Po;nte'rnMarl< Flywheel Timing Indicator Fig. 158 Checking WOT ignition timing -9.9/15 hp motors the idle timing screw contacts the idle timing stopper. Finally, at this point the link joint timing indicator should align with the marking on the flywheel (see the accompanying illustration). If this setting is correct, no further checking/adjustment is necessary. However, if the marks do not align as indicated continue the procedure in order to properly set the idle timing. 9. Tum the flywheel clockwise until the dial gauge indicates that the piston is 0.005 in. (0.12mm) After Top Dead Center (ATDC}. 10. Turn the magneto control lever so that the idle timing screw contacts the idle timing stopper. Now adjust the screw so that the link joint timing indicator aligns properly with the flywheel mark. 11. Remove the dial gauge and install the spark plug. 12. Check the throttle linkage adjustment. 2-50 MAINTENANCE & TUNE-UP Fig. 160 .••then install a dial gauge throug.h the No. 1 spark plug hole Cover Pointer Flywheel Mark link Joint Timing indicator Idle Timing stopper Fig. 161 Checking Ignition Idle timing THROTILE LINKAGE ADJUSTMENT 3. Locate the throttle cables where they connect to the magneto control lever bracket. Loosen the locknuts for both the pull and push cables. 4. Tum the magneto control lever until the idle timing screw contacts the idle timing stopper, then rotate the adjuster for the lower cable (1) on the bracket until there is 0.04 in. (1mm) of free-play between the pulley stoppers and the free acceleration lever. Then tighten the locknut for the lower cable (1). 5. Next, turn the adjuster for the upper cable (2) until there is 0.04 in. (1 mm) of free-play on the throttle cable at the pulley, then tighten the locknut. 6. Recheck the throttle operation checking that the screw contacts the sto..per and that it operates smoothly without binding. CHECKING/ADJUSTING THE STARTER LOCKOUT ..SY • See Figure 165 This model contains a starter lockout safety feature to prevent the motor from being started while In gear. The system should be checked at each tune-up to ensure that it Is adjusted and functioning properly. Checking is a simple matter of placing the motor in gear and gently attempting to start the motor. If the starter will not rotate, the system is functioning and no further attention is required. However, if the motor rotates in gear, then adjust the cable as follows: 1. Begin with the engine not running and shifter positiin Neutral oned 2. Loosen the lockout cable locknut (at the cable mounting bracket). 3. Turn the adjuster nut (located at the cable mounting bracket, on the opposite side of the locknut) until the end of the stopper aligns with the marking on the starter case. 4. Once positioned properly, retighten the locknut to hold the cable in this position. 5. Verity that the lockout is now working properly. IDLE SPEED ..ODERATE • See Figure 166 l. Mount the engine in a test tank or move the boat to a body of water. 2. Remove the cowling and connect a tachometer to the powerhead. 3. Loosen the acceleration rod lock screw. 4. Turn the pilot screw (the threaded horizontally into the top side of the carburetor body) inward until it JUST lightly seats and then back out the specified number of turns, as indicated in the Carburetor Set-Up Specifications chart, found in the Fuel System section. 5. Start the engine and allow it to warm to operating temperature. 6. Check engine speed at idle. The powerhead should idle at the rpm • See Figures 161 thru 164 IJRefer to the numbers in the accompanying illustration for component identification. 1. Check and adjust the ignition timing, as necessary. 2. Check the throttle linkage adjustment by fully closing the throttle grip and checking to make sure the idle timing screw contacts the idle timing stopper. If so, stop right here, since the adjustment is fine. If not, continue with the procedure to prope..y adjust the throttle linkage. specified in the Tune-up Specifications chart. 7. Place the engine in gear and check engine trolling speed in the same manner. 8. If adjustment is necessary, rotate the idle adjustment screw (the spring loaded screw threaded vertically downward into contact with the throttle lever, not the pilot screw) until the powerhead idles at the required rpm. Turning thescrew inward will increase idle speed, while turning the screw outward will decrease speed. 9. Pull the acceleration rod through the throttle lever bore until the idle timing screw contacts the idle timing stopper, then tighten the acceleration rod lock screw. Fig. 162 To adjust the throtlle linkage,start by loosening the cable locknuts .•• Fig. 163 ••.turn the lower cable to adjust free-play at the pulley stoppers.•• Fig. 164 •••then turn the upper cable to adjust free-play on the cable Itself MAINTENANCE & TUNE-UP 2ˇ51 . . . Lever ' ___: Stopper Fig. 167 Checking/adjusting WOT ignition Timing -20/25 hp (395cc) motors Fig. 168 Usea dial gauge to find TDC and then to measure piston depth Fig. 169 Checking/adjusting idle ignition Timing -20/25 hp (395cc} motors Fig. 165 Starter lockout adjustment ˇ 9.9/15 hp motors Pilot Lock Screw Fig. 166 1dle speed adjustment ˇ 9.9/15 hp motors 20125 Hp (395cc) Models IGNITION TIMING + See Figures 167, 168 and 169 The complete timing check and adjustment procedure takes place with the engine NOT running. The good news is that means you won't need a tachometer or timing light, and nor will you need to mount it in a test tank or launch the boat. The bad news is that you WILL need a dial gauge. Ok,maybe that's not a bad thing cause you'll be able to do other things with it, like check rotor run-out on the tow vehicle (or on the crankshaft if you ever rebuild the powerhead). • Refer to the letters in the accompanying illustration for component identification . 1. Remove the cowling lor access and locate the timing marks on the flywheel. 2. To check the WOT ignition timing (fully-advanced setting) slowly turn the flywheel by hand in the normal direction of rotation {clockwise) and align the timing pointer with the specified timing mark on top of the flywheel. Please refer to the Tune-Up Specifications chart in this section for timing specs. 3. With the timing pointer aligned with the appropriate specification mark on the flywheel, turn the magneto control lever so that it contacts the full advanced stopper. At this point check the timing indicator {a) under the flywheel and make sure it aligns with the marking (b) on the flywheel (for clarification, please refer to the accompanying illustration). If adjustment is necessary, continue with the procedure. 4. Loosen the locknut on the link at the top of the magneto control lever and disconnect the link joint from the lever. 5. Remove the spark plug from the No. 1 cylinder, then attach a dial gauge to the spark plug hole in order to measure piston height. 6. Slowly turn the flywheel by hand until the piston reaches TDC, then zero the dial gauge. Now turn the flywheel very slowly Counterclockwise (YES, this is one of the few times we'll ever tell you to do that) until the dial gauge shows the piston is 0.13 in. (3.34mm) BTDC. 7. With the piston at this position, manually tum the magneto control lever to the WOT position and adjust the link joint length so that the timing indicator aligns with the mark under the flywheel. Connect the link joint and tighten the locknut to secure the adjustment. 8. Next, check the idle timing by turning the flywheel clockwise until the timing pointer aligns wnh the appropriate idle timing mark on top of the flywheel. In this position, turn the magneto control lever the opposije direction, so it contacts the idle stopper and check if the timing indicator (a) aligns with the mark under the flywheel. If not, continue wnh the procedure in order to set the idle liming. 9. If idle adjustment is necessary, simply turn the idle stopper screw until the magneto lever moves sufficiently to align the timing indicator (a) with the mark (b) below the flywheel. CHECKING/ADJUSTING THE CARBURETOR LINK ROD + See Figure 170 The 2 carburetors used on this model are connected by a link that ensures both throttle valves will open and close at the same time. When performing adjustments, check the link to make sure that both throttle valves open and close together. If not, adjust the link rod as follows: 1. Loosen the idle speed adjustment screw enough to fully close the throttle valves (count the number of turns you loosen it in order to preserve current idle speed adjustment). 2. Loosen the link rod lock-screw and reposition the link so that the throttle valves are fully closed, then tighten the lock-screw. 3. Open and close the throttle a few times making sure the throttle valves move together (from idle to WOT positions). 4. Turn the idle speed adjustment screw inward the same number of turns you counted while backing it out. 5. Continue the timing and synchronization checks/adjustments, making sure to check/adjust the idle speed. 2ˇ52 MAINTENANCE & TUNE-UP CHECKING/ADJUSTING THE CARBURETOR PICKUP TIMING + See Figures 171 and 172 ..SY • Refer to the letters in the accompanying illustration for component identification. 1. Check/adjust the ign..ion timing and carburetor link. 2. Check for proper carburetor pickup timing by slowly turning the flywheel clockwise until the appropriate timing mark on top of the flywheel aligns with the timing pointer. Please refer to the Tune-Up Specifications chart in this section for timing specs. 3. With the timing pointer aligned w.h the appropriate specif ication mark on the flywheel, turn the magneto control lever so that it just contacts the throttle roller. At this point check the timing indicator (a) under the flywheel and make sure it aligns with the marking on the flywheel (for clarification, please refer to the accompanying illustration). If adjustment is necessary, continue with the procedure. 4. Loosen the throttle roller adjusting screw and (with the flywheel still in the appropriate pickup timing position), then turn the magneto control lever so the mark on the underside of the flywheel aligns with the indicator mark. Now set the roller so it contacts the magneto lever and tighten the roller adjusting screw. CHECKING/ADJUSTING THE THROTILE CABLE + See Figure 173 ..SY Set the shifter into the forward position; then operate the throttle, checking for smooth, correct operation. VISually inspect the throttle control cable for signs of damage or excessive wear and replace, if necessary. Wrth the throttle in the WOT position, check the indicator mark to see if it aligns with the throttle roller. If not, adjust the throttle cable, as follows: 1. With the shift lever still in the forward position, move the magneto control lever to the WOT stop. 2. Locate the 2 throttle cables in the bracket at the base of the linkage assembly, the top cable is the PULL or accelerator cable, the bottom is the PUSH or decelerator cable. loosen the locknuts on both cables. 3. Turn both cable adjusters until the throttle roller is aligned with the indicator mark, then loosen the cable adjuster on the PUSH (bottom) cable until there is 0.12 in. (3mm) of free-play at the throttle grip. Then tighten both locknuts. 4. Verify that throttle operation (speciftcaUy the movement of the magneto control lever) is smooth. Repair or readjust as necessary. CHECKING/ADJUSTING THE DIAPHRAGM + See Figure 174 ..SY Fully close the throttle to the idle position and check that the diaphragm plunger is fully retracted and the throttle control lever is closed all the way. If not, or if the diaphragm operation is rough, it should be adjusted. Adjustment is a relatively simple matter. loosen the 2 botts on the side of the bracket, then place the magneto control lever in the full retard (idle) pos..ion and retighten the bolts. CHECKING/ADJUSTING THE NEUTRAL OPENING LIMIT + See Figure 175 SY These motors use a type of mechanical limiter to prevent engine overspeed in Neutral by limiting the throttle position. The checking and adjustment procedures are pretty much the same, involving operating the motor in Neutral (in a test tank, using a flushing device or on a body of water) and making sure the engine will not go beyond about 3500-4100 rpm. To check anc:Vor adjust the neutral opening limit, proceed as follows: • Refer to the numbers in the accompanying illustration for component identification. 1. Mount the engine in a test tank or launch the boat on a body of water. 2. Remove the cowling and attach a tachometer. 3. Set the shift lever to Neutral and start the engine. 4. Allow the engine to operate and come up to normal operating temperature. 5. Set the throttle so the engine speed is 3500-3800 rpm. It should not go any further in Neutral. Magneto Control a • Flywheel Mark b • Indicator Mali< Fig. 170 Idle speed and carburetor link rod adjustment screws •20/25 hp (395cc) motors Fig. 171 Checking/adjusting the carburetor pickup timing ˇ 20/25 hp (395cc) motors Fig. 172 Make sure the mark under the flywheel mark aligns with the Indicator mark Fig. 173 Checking the throttle cable adjustment • 20/25 hp (395cc) motors MagnetoControllever Fig. 174 Adjusting the diaphragm •20/25 hp (395cc) motors Fig.175 Adjusting the neutral opening limit •20/25 hp (395cc) motors ... ... ...ˇ 6. If adjustment is necessary, turn the neutral speed control screw (on the linkage just inboard of the magneto control lever, for clarificalion please refer to the accompanying illustration}. Turning the screw INWARD will DECREASE speed, while turning the screw OUTWARD will INCREASE speed. IDLE SPEED + See Figure 170 1. Check and/or adjust the Neutral Opening Limit. Leave the engine mounted in the test tank or keep the boat launched. TE 2.Turn the pilot screw (mounted diagonally downward into the top side of the carburetor body} in until it lightly seats and then back out the specified number of turns, as indicated in the Carburetor Set-Up Specifications chart, found in the Fuel System section. 3. Start the engine and allow it to warm to operating temperature. 4. Check engine speed at idle. The powerhead should idle at the rpm specified in the Tune-up Specifications chart. 5. Place the engine in gear and check engine trolling speed in the same manner. 6. If adjustment is necessary, rotate the idle adjustment screw, (NOT the pilot screw} until the powerhead idles at the required rpm. The idle adjustment screw is mounted vertically, just behind the carburetor link and contacts the throttle valve. Turning the screw INWARD will increase idle speed, while turning the screw OUTWARD will decrease idle speed. + See Figure 176 This model contains a starter lockout safety feature to prevent the motor from being started while in gear. The system should be checked at each tune-up to ensure that it is adjusted and functioning properly. Checking is a simple matter of placing the motor in gear and gently attempting to start the motor. If the starter will not rotate, the system is functioning and no further attention is required. However, if the motor rotates in gear, then adjust the cable as follows: 1. Begin with the engine not running and shifter positioned in Neutral. 2. Loosen the locknut at the top of the cable (it's the small nul), near the starter housing. 3. Next, use the large adjuster nut (located just below the adjuster nut) to change the length of the cable until the starter stop plunger line is centered in the sight hole. 4. Once positioned properly, retighten the locknut to hold the cable in this posijion. 5. Verify that the lockout is now working properly. + See Figure 177 The oil pump link is properly adjusted when there is 0.02 in. (0.5mm} of clearance, measured between the oil pump lever and the WOT stopper when the carburetor throttle valve is at WOT. To check this dimension open the throttle valve and measure the distance using a feeler gauge. If adjustment is necessary, proceed as follows: 1. Loosen the locknut at the top of the oil pump link, then disconnect the link joint from the throttle control lever. 2. Open the carburetor throttle valve to the WOT position and position the oil pump lever 0.02 in. (0.5mm) from the WOT stopper. Gently push the lever against a feeler gauge to find the correct distance. then hold the lever and gauge in that position (an assistant is really handy here}. 3.Adjust the link joint until the hole aligns with the oil pump set pin, then reconnect the link joint. 4. Verify that the throttle valve opens fully and that the proper gap now exists between the pump lever and WOT stopper, then tighten the locknut. MAINTENANCE & TUNE-UP 2-53 Fig. 176 Adjusting the starter lockout •20/25 hp (395cc) motors Throttle Control Lever rˇ) .. Clearance Fig. 177 Oil pump link adjustment -20/25 hp (395cc) motors 20'25 hp (430cc) Models • This includes most of the C25 models. IGNITION TIMING 1. Pry the link rod free from the ball joint on the magneto control lever. 2. Remove the park plug and install a dial indicator in the No. 1 cylinder spark plug hole. 3. Rotate the flywheel clockwise until the piston is at top dead center (TDC). 4. Check the timing pointer with the flywheel timing scale. If alignment is incorrect. loosen the timing pointer nut and move the pointer as required to align the pointer with the o• mark on the flywheel. 5. Rotate the flywheel clockwise until the timing plate is aligned to the full advance timing as specified in the Tune-up Specifications chart. 6. Set the magneto base to the full-advanced position and set the stopper. 7. Loosen the locknut on the link rod and adjust the length of the rod until it can be snapped back into place on the ball joint of the magneto control lever, without any movement at the other end of the rod. CARBURETOR LINKAGE ADJUSTMENT 1. Loosen the carburetor control link set screw. 2. Set the magneto control lever in the full-advanced position. 3.Adjust the guide collar so that the roller contacts the high point of the accelerator cam. 4. Hold down the control ring and tighten the set screw securely . .. : . -.. ... . . .. . ˇˇ . . ' 5. If the timing mark is not aligned properly, stop the engine, shift the lower unit into FORWARD and rotate the flywheel until the timing marks align properly. 6. Rotate the magneto base and align the timing mark with the ignition mark on the rotor. 7. If the magneto base stopper is not in contact with the full open stopper on the cylinder body, loosen the holding bolts and adjust until proper contact is made. 8. Ensure the full open (T) mark on the accelerator cam aligns with the center of the cam roller. 9. If alignment is not as specified, loosen the accelerator cam bolts and align the full open (T) mark with the center of the carburetor throttle roller. Tighten the holding bolts. 10. Remove the starter. 11. Loosen the rod adjusting screw and adjust the rod so the throttle is fully open and the open stopper is pushed up against the stopper. Tighten the screw. 12. Install the starter. IDLE SPEED 2-54 MAINTENANCE & TUNE-UP THROTILE LINKAGE ADJUSTMENT TE 25/30 Hp (496cc 2-Cylinder) Models 1. Mount the engine in a test tank or move the boat to a body of water. 2. Remove the cowling and connect a tachometer and a timing light to the powerhead. 3. Start the engine and allow it to warm to operating temperature. Place the lower unit in Neutral. 4: Increase engine speed to 4500-5500 and aim the timing light at the indicator on the starter case. It should align with the specified timing full throttle timing figure in the Tune-up Specifications chart. 1. Place the lower unit in FORWARD gear and loosen the joint link set screw. 2. Adjust the accelerator control link rod so that the center to center length is 2.72 in. (69mm). IDLE SPEED 1. Mount the engine in a test tank or move the boat to a body of water. 2. Remove the cowling and connect a tachometer to the powerhead. 3. Turn the pilot screw in until it lightly seats and then back out the specified number of turns, as indicated in the Carburetor Set-Up Specifications chart, found in the Fuel System section. 4. Start the engine and allow it to warm to operating temperature. 5. Check engine speed at idle. The powerhead should idle at the rpm specified in the Tune-up Specifications chart. 6. Place the engine in gear and check engine trolling speed in the same manner. 7. If adjustment is necessary, rotate the idle adjustment screw (not the pilot screw) until the powerhead idles at the required rpm. IGNITION TIMING 1. Mount the engine in a test tank or move the boat to a body of water. 2. Remove the cowling and connect a tachometer to the powerhead. 3. Turn the pilot screw in until it lightly seats and then back out the specified number of turns, as indicated in the Carburetor Set-Up Specifications chart, found in the Fuel System section. 4. Start the engine and allow it to warm to operating temperature. 5. Check engine speed at idle. The powerhead should idle at the rpm specified in the Tune-up Specifications chart. 6. Place the engine in gear and check engine trolling speed in the same manner. 7. If adjustment is necessary, rotate the idle adjustment screw (not the pilot screw) until the powerhead idles at the required rpm. THROTILE CABLE 1. With the lower unit in FORWARD gear, twist the throttle grip to the wide-open throttle position. 2. The magneto base stopper should be in contact with the full open stopper. 3. If adjustment is necessary, loosen the adjust locknut on the pull side of the throttle cable. Turn the adjusting bolt until all slack is taken up and tighten the locknut. 4. Loosen the adjust locknut on the push side of the throttle cable. Turn the adjusting bolt until 0.12 in (3mm) slack is present with the throttle grip in the Slow position. Tighten the locknut. 5. Ensure the throttle shaft full open stopper contacts the full open stopper on the carburetor w..h the throttle in the wide-open throttle position. 6. If the throttle stopper is not a specified, loosen the locking screw and adjust it to specification. 7. Now adjust the throttle control link. THROTILE CONTROL LINK • The throttle cable must be adjusted prior toadjusting the throttle control link. 1. Twist the throttle grip to the wide-open throttle position. 2. With the lower unit in FORWARD gear, ensure the magneto base stopper is in contact w..h the stopper on the cylinder and the throttle control lever in contact w..h the stopper on the bottom cowling. 3. If these condition do not exist, proceed as follows. 4. Disconnect the link rod between the CDI magneto base and the magneto control lever at the ball joint. 5. Rotate the magneto base plate until the stopper is in contact with the stopper on the cylinder. 6. Twist the throttle grip to the wide-open throttle position. 7. Adjust the connector on the end of the link rod so the center to center length is 1.81 in. (46mm). 8. Connect the link rod between the CDI magneto base and the magneto control lever at the ball joint without moving the magneto base. 40 Hp (2-Cylinder) Model • This includes most C40 models. DYNAMIC TIMING + See Figures178, 179 and 180 1. Mount the engine in a test tank or on a boat in a body of water. TE 2. Obtain a timing light and clip the pickup lead to the No. 1 spark plug lead. 3. Connect a tachometer to the powerhead per the instructions with the instrument. 4. Start the engine and allow it to warm to operating temperature. 5. Push the magneto control lever downward until the lower screw tip barely makes contact with the stopper. This action fully advances the timing. Allow the powerhead to operate at approximately 4,500 rpm. 6. Aim the timing light at the timing pointer. The pointer should align halfway between the 21-23° BTDC marks embossed on the flywheel. If the marks align, the full-advanced timing is correctly set. 7. Shut down the powerhead. Pry off the link from the ball joint at the magneto control lever ball joint. Restart the powerhead. Pull the magneto control lever all the way up. Aim the timing light at the timing pointer and use the free end of the link rod to rotate the magneto base until the timing pointer aligns properly. MAINTENANCE & TUNE-UP 2-55 Fig. 178 Pushthe magneto control lever Fig. 180 Check to be sure the upper downward until the lower screw tip barely Fig. 179 Pry off the link from the ball joint at adjusting screw tip barely makes contact makes contact with the stopper the magneto control lever ball joint with the stopper 8. Shut down the powerhead. Adjust the length of the link rod to snap back onto the ball joint of the magneto control lever without moving the magneto base or the magneto control lever. Snap the link rod back onto the ball joint of the magneto control lever. 9. Start the powerhead and allow it to idle. Check to be sure the upper adjusting screw tip barely makes contact with the stopper. 10. Aim the timing light at the timing pointer. The pˇointer should align half way between the 1ˇ3° ATDC marks embossed on the flywheel. If the marks align, the fully retarded timing is correctly set and the timing procedures are completed. If the marks do not align, then proceed as follows: With the powerhead still running, continue to aim the timing light at the pointer and at the same time adjust the upper adjusting screw until the pointer aligns properly. Shut down the powerhead. STATIC TIMING Full Advance Adjustment + See Figures 181 thru 184 TE 1. Remove all three spark plugs from the powerhead. Install a dial indicator into the No. 1 cylinder opening. 2. Rotate the flywheel clockwise until the dial indicator indicates the piston is at TDC (top dead center). Check the timing pointer to be sure it 4. Rotate the lower adjustment screw until the tip contacts the stopper. Tighten the locknut to hold this new adjusted position. Full Retard Adjustment + See Figures 185 and 186 1. Rotate the flywheel clockwise until the timing pointer aligns with the 130 ATDC mark embossed on the flywheeL 2. Rotate the upper adjustment screw until the tip contacts the stopper. Tighten the locknut to hold this new adjusted position. CARBURETOR LINK TE + See Figures 187 and 188 1. Pull off the accelerator lever rod. This rod connects the three throttle levers together and is a set length. Loosen but do not remove the throttle valve screws on the top and center carburetors, by rotating the screws clockwise. Yes, they are rotated clockwise, because they have left hand threads. This fact is emphasized by the arrow and the word OFF embossed on each lever. aligns with the TDC mark embossed on the flywheel. If the mark is 2. Loosen the idle speed adjustment screw. Snap on the accelerator rod misaligned, loosen the set screw on the timing plate and align the pointer over all three ball joints. Push down on the cam to close all throttle valves with the flywheel mark. Tighten the screw to hold the adjustment. and then tighten the throttle valve screws on the top and center carburetor. 3. Rotate the flywheel clockwise until the timing pointer aligns with 21 This is accomplished by rotating the screws counterclockwise. 230 on the flywheeL Fig. 182 Rotate the flywheel clockwise until Fig. 181 Install a dial indicator Into the No. 1 the dial indicator indicates the piston is at cylinder opening TDC ( top dead center) Fig. 183 Rotate the flywheel clockwise until the timing pointer aligns with 21-23• on the flywheel 2-56 MAINTENANCE & TUNE-UP Fig. 184 Rotate the lower adjustment screw until the tip contacts the stopper Fig. 185 There Is no mark between TOC and 5" on the flywheel. Adjust the timing so the pointer falls just to the left of the s•mark Fig. 187 Accelerator lever rod location adjacent to the throttle screws IDLE SPEED + See Figure 189 ..ODERATE 1. Mount the engine in a test tank or move the boat to a body of water. 2. Remove the cowling and connect a tachometer to the powerhead. 3. Turn the pilotscrew in until .. lightly seats and then back out the specified number of turns, as indicated in the Carburetor Set-Up Specifications chart, found in the Fuel System section. 4. Start the engine and allow .. to warm to operating temperature. 5.Check engine speed at idle. The powerhead should idle at the rpm specified in the Tune-up Specifications chart. 6. Place the engine in gear and check engine trolling speed in the same manner. 7. If adjustment is necessary, rotate the idle adjustment screw (not the pilotscrew)until the powerhead idles at the required rpm. THROTILE LINK + See Figure 190 1. Disconnect the magneto control link. 2. Align the full-closed mark on the pulley with the mark on the bracket. 3. Rotate the magneto base clockwise until the full-closed side of the magneto base stopper No. 1 contacts theadjust boll forthe magneto base stopper No. 2. Fig. 186 Rotate the upper adjustment screw until the tip contacts the stopper and tighten the locknut Fig. 188 Push the cam to close all throttle valves; then tighten the valve screws by rotating them counterclockwise Fig. 189 Pilot and idle speed screw locations on the side of the powerhead 4. Adjust the plastic snap-on connector on the end of the link rod until it can be reconnected to the control lever ball stud without changing the position of the linkage or magneto base. 5. Align the wide-open throttle mark on the pulley with the mark on the throttle bracket. 6. Adjust the throttle link joint so the wide-open throttle mark on the throttle cam aligns with the center of the carburetor throttle roller. 48 Hp (2-Cylinder) Models IDLE SPEED + See Figures 191 and 192 TE 1. Mount the engine in a test tank or move the boat to a body of water. 2. Remove the cowling and connect a tachometer to the powerhead. 3. Start the engine and allow it to warm to operating temperature. 4. Check engine speed at idle. The powerhead should idle at the rpm specified in the Tune-up Specifications chart. 5. Place the engine in gear and check engine trolling speed in the same manner. 6. If adjustment is necessary, shut the motor down, then adjust both of the pilot screws (they are mounted horizontally into the side of the MAINTENANCE & TUNE-UP 2-57 Fig. 190 Magneto link cont.rol rod should beadjusted so that it can bereconnected to the control lever ball stud without changing the position of the linkage or magneto base carburetors). Turn the pilot screw in until it lightly seats and then back out the specified number of turns, as indicated in the Carburetor Set-Up Specifications chart, found in the Fuel System section. 7. Restart and re-warm the powerhead, then finalize the idle speed setting by rotating the idle adjustment screw (not the pilot screws) until the powerhead idles at the required rpm. The idle speed adjustment screw is located on the lower carburetor, just behind the carburetor linkage, it contacts the throttle lever. IGNITION TIMING + See Figures 193 thru 196 1. 1f the timing pointer has been moved even SLIGHTLY during maintenance or engine repair, then you'll have to start this procedure by adjusting the timing plate position as follows: a. Remove the spark plug from the No. 1 (top) cylinder and install a dial gauge into the spark plug hole in order to measure piston depth. • H it is difficult to tum the flywheel, go ahead and remove the spark plug from the No. 2 (lower) cylinder as this will alleviate engine compression. b. Tum the flywheel CLOCKWISE slowly, by hand, until the piston reaches Top Dead Center (TOC) as indicated on the dial gauge. B • Decreases speed Fig. 191 Pilot screw adjustment ˇ 48 hp 2ˇ cylinder motors Fig. 192 1dle speed screw adjustment ˇ 48 hp 2-cylinder motors Fig. 193 Use a dial gauge to ensure the No. 1 cylinder is at TDC•.• Flywheel Fig. 196 Checking/adjusting WOT timing ˇ 48 hp 2-cylinder motors 2ˇ58 MAINTENANCE & TUNE-UP c. With the No. 1 cylinder piston at TDC check to make sure the timing pointer is aligned with the TOC mark on the flywheel. If not, loosen the set screw and adjust the pointer position, then secure it with the set screw. Remove the dial gauge and reinstall the spark plug(s). 2. To check and adjust the idle timing, proceed as follows: • Refer to the numbers In the accompanying illustration for component identification. a. Turn the flywheel CLOCKWISE slowly, by hand, until the timing pointer is facing the correct idle timing specification as listed in the Tune-Up Specifications chart in this section. At this point disconnect the magneto control rod (1) from the magneto base (2) and movethe base clockwise until it contacts the idle stopper (3). If the mark on the flywheel {4) aligns with the mark on the magneto base (5), the idle timing is correct. b. However, if the marks are not aligned as noted, loosen the locknut on the idle stopper screw and tum the screw until the marks are in alignment. Turning the screw clockwise will advance timing, while turning the screw counterclockwise will retard timing. Set Screw Fig. 194 Then make sure the timing pointer is aligned with the flywheel TDC mark c. Once the adjustment is correct, tighten the locknut to hold theidle stopper screw in place. d. You can leave the magneto control rod (1} disconnected from the magneto base (2) as this will be necessary to check/adjust the WOT timing. 3. To check and adjust the WOT timing, proceed as follows: • Refer to the numbers in the accompanying illustration for component identification. a. Turn the flywheel CLOCKWISE slowly, by hand, until the timing pointer is facing the correct WOT timing specification as listed in the TuneUp Specifications chart in this section. Make sure the magneto control rod (1) is still disconnected from the magneto base (2), or disconnect them now. Then move the base counterclockwise until it contacts the WOT stopper {3}. If the mark on the flywheel (4) aligns with the mark on the magneto base (5}, the WOT timing is correct. b. However, if the marks are not aligned as noted, loosen the locknut on the WOT stopper screw and turn the screw until the marks are in alignment. Turning the screw clodi,_..c CAUTION The end of the cable joint MUST be threaded at least 0.31 in. (8mm) onto the cable otherwise it could loosen in service causing a loss of throt11e control (at potentially very serious navigation hazard). 5. lighten the locknut, then install the link joint and secure using the retaining clip. 6. Reconfirm proper adjustment and throttle operation. SHIFT CABLE ADJUSTMENT + See Figure 258 Visually check the shift linkage movement in response to the shift handle. If the shifter does not engage properly or smoothly, adjust, as follows: 1. Set the shift control lever to the Neutral position. 2. Remove the retaining clip and disconnect the shift cable joint from the powerhead linkage. 3. Align the center of the linkage set pin with the mark in the middle of the shift bracket. 4. Loosen the locknut, then adjust the position of the shift cable joint (by turning the joint inward or outward on the cable threads) until its mounting hole aligns with the linkage set pin at the center of the bracket. lighten the locknut to hold it in position on the cable. ....: ..( CAUTION Make sure that after adjustment the cable joint is threaded over at LEAST 0.31 in. (8mm) of cable threads, otherwise there is a risk that the joint could separate in service causing a severe navigation/control hazard. 5. Position the cable joint over the control lever set pin and secure using the retaining clip. Magneto Control Lever Link Joint Throttle Lever Roller Fig. 257 Adjusting the pickup timing -E75, 75A Models, 85A Models, E60J (1140cc) motors CHECKING/ADJUSTING THE STARTER LOCKOUT + See Figure 259 Manual start models of this motor contain a star . ., .... . to prevent the motor from being started while in gear. The system should be checked at each tune-up to ensure that it is adjusted and functioning properly. Checking is a simple matter of pia..ing the motor in gear an.. gently attempting to start the motor. if the starter will not rotate, the system IS functioning and no further attention is required. However, if the motor rotates in gear, then adjust the cable as follows: 1. Begin with the engine not running and shifter positioned in Neutral. 2. Loosen the screw securing the cable adjusting plate to the starter housing. 3. Reposition the adjusting plate until the mark on the stopper (a) aligns with the mark on the cam guide (b), then retighten the adjusting plate screw. 4. Verily that the lockout is now working properly. V4 and V6 Carbureted Motors IGNITION TIMING + See Figures 260 thru 264 TE On these Yamaha outboards Ignition liming is checked by positioning the No. 1 piston in various positions and checking the corresponding timing marks and magneto linkage. WOT timing is then adjusted, if necessary, by changing the length of the magneto control link (the link that connects the magneto lever to the timer base/pulser coil). 1. if equipped, remove the flywheel cover for access. 2. Slowly rotate the flywheel by hand (CLOCKWISE) in t..e n?rmal . direction of rotation until the timing pointer on the powerhead IS aligned w1th WOT timing specification for the motor. Please refer to the Tune-Up Specifications chart in this section for details on timing specs. Set Fig. 258 Shift cable adjustmentˇ E60 (849cc) shown (E75, 75A Models, 85A Models, E60J motors, similar) Cable AdjustingPlate Fig. 259 Starter lockout adjustment •E60 (849cc) and E75, 75A Models, 85A Models, E60J (1140cc) motors MAINTENANCE & TUNE-UP 2-75 3. With the timing pointer aligned with the proper WOT timing specification, manually rotate the magneto control lever CLOCKWISE until it contacts the WOT stopper. Now follow the linkage on top of the magneto control lever under the flywheel (where it contacts the timing base/pulser coil assembly). The timing mark on the underside of the flywheel should align with the mark on the timing base/pulser coil. If so, skip the WOT timing adjustment step and go on to check the Idle Timing. 4. If WOT timing must be adjusted, proceed as follows: a. Make sure the lower unit in Neutral. b. Remove all 4 or 6 spark plugs to ease compression and allow the motor to be rotated freely. I. Continue to turn the flywheel almost another complete rotation until you reach the specified distance BEFORE Top Dead Center (BTDC). The distance varies by model as follows: • BOJ, 100, 130 and 140 hp motors -0.12 in. (3.05mm) BTDC • 115A -0.13 in. (3.33mm} BTDC • All other 115 Models -0.15 in. (3.91mm) BTDC • 150A, L150A, C150TR and 175A -0.09 in. (2.28mm} BTDC • 150F, L150F, D150H, D150TR, 1750, S175D and S175TR-0.12 in. (3.05mm) BTDC • 105J, S150F, LS150F, S150TR, L150TR, 175F, P175TR, 200G and P200TR -0.13 in. (3.33mm} BTDC c. On most models (including all 1999 and later models) it is a good idea to remove the air intake silencer for better access. d. Install a dial indicator in the No. 1 cylinder spark plug hole so that it can measure piston movement. e. Slowly rotate the flywheel clockwise until it reaches TDC (the absolute top of piston travel}, then zero the dial gauge. • 200A and L200A -0.08 in. (2.05mm) BTOC • 150G, P150TR, 200F, L200F and 200TR -0.10 in. (2.53mm) BTDC • S200F, LS200F, S200TR, L200TR and 225 • 0.11 in. (2.78mm) BTDC g. Check the timing pointer on the powerhead to see with what specification on the flywheel it is currently aligned. Compare this to the WOT timing spec in the Tune-Up Specifications chart. If necessary, loosen the set- Fig. 260 To check WOT timing, turn the flywheel to align the spec with the pointer .• Fig. 261 •••then manually rotate the magneto control lever clockwise, against the WOT stopper ... Fig. 262 •.•and check the timing marks under the flywheel for alignment WOT Stopper Fig. 263 WOT timing is adjusted by changing the length of the magneto control link ˇ V4 and V6 Carbureted Motors (V4 1inkage shown, V6 very similar) a -Flywheel Mark b -Magneto Base Mark Idle Stopper Screw Fig. 264 Idle timing is adjusted using the idle stopper screw •V4 and V6 Carbureted Motors (V6 linkage shown, V4 similar} 2-76 MAINTENANCE & TUNE-UP screw for the timing pointer and slide it one way or the other slightly to align it with the proper WOT timing spec. h. Now adjust the length of the WOT stopper screw to achieve the specified length between the end of the WOT stopper and the point where the threads enter the stopper mounting bracket (on the stopper side of the bracket). The length varies with model as follows: • 80J, 100, 130 and 140 hp motors -1.14 in. (29mm) • E115A • 0.96 in. (24.5mm) • C115, C115TR and 115B ˇ 0.87 in. (22mm) • All other 115 Models ˇ1.02 in. (26mm) • 150A, L150A, C150TR, 175A, 1750, S175D and S175TR • 0.93 in. (23.5mm)• 150F, L150F, 105J, S150F, LS150F, S150TR and L150TR ˇ 0.85 in. (21.5mm) • D150H and D150TR ˇ 1.62 in. (41.2mm) • 150G and P150TR -1.71 in. (43.5mm) • 175F, P175TR, 200G and P200TR • 1.57 in. (40mm) • 200A and L200A • 0.98 in. (25mm) • 200F, L200F and 200TR ˇ 0.94 in. (24mm) • S200F, LS200F, S200TR, L200TR and 225 • 1.67 in. {42.5mm) i. Disconnect the magneto control link from the top of the control lever, then turn the control lever clockwise until it contacts the WOT stopper. j. WOT timing is adjusted by loosening the locknut and adjusting the length of the magneto control link so that it can reconnect to the control lever when the timing mark on the underside of the flywheel aligns with the timing base/pulser coil marking. k. Once the adjustment is correct, tighten the locknut and reconnect the link to the top of the magneto control lever. 5. Next, it is time to check the Idle Timing by turning the flywheel clockwise again until the proper Idle Timing specification on the flywheel aligns wijh the timing pointer. 6. Manually rotate the magneto control lever counterclockwise until the Idle Stopper (threaded through the control lever itself, a little below where the lever contacts the WOT stopper) contacts the crankcase. 7. Just like with the WOT timing check, in this position the timing mark on the magneto timer base/pulse coil should align with mark on the underside of the flywheel. If so, you're done with the timing procedure. However, if not, you'll have to adjust the Idle Timing, by turning the Idle Stop screw inward or outward until the marks align properly. 8. If the air intake silencer assembly was removed, keep it off and proceed to the Synchronizing the Carburetors procedure. SYNCHRONIZING THE CARBURETORS + See Figures 265, 266 and 267 • Check and/or adjust the ignition timing prior to performing this procedure. 1. If not done already for Ignition Timing adjustment, remove the air silencer for access and so that you can observe the throttle valves. Fig. 265 Carburetor synchronization means all carb throttle valves open and close at the same time Fig. 266 Idle adjust screw 2. Manually rotate the lower (V4) or middle (V6) throttle lever and observe the opening and closing of all the throttle valves. They must open and close at the same instants in order for the motor to idle properly. If there are idle problems, or you observe one or more throttle valves out of synchronization with the rest, continue with this procedure in order to adjust them. 3. Loosen the idle adjust screw on the lower (V4) or middle (V6) carburetor until it no longer contacts the throttle arm stopper. • You can make Idle Speed adjustment easier on yourself if you count the number of turns that you loosen the idle adjust screw. 4. Next, loosen the throttle valve screw{s) of the upper (V4) or upper and lower (V6) carburetors by turning each CLOCKWISE and making sure the throttle valves are fully closed. 5. Push VERY lightly inward on the throttle valve for the lower (V4) or middle (V6) carburetor to make sure it is fully closed and hold it while retighten the throttle valve screw or screws, as applicable. Be sure to tighten the throttle valve screws COUNTERCLOCKWISE, since they have left-hand threads. 6. Slowly tighten the idle adjust screw until it contacts the throttle arm stopper. From this position, tighten it another 1 to 1-1/8 turns further as a starting position (unless you counted the number of turns at the beginning of this procedure, then tighten it the same number of turns you loosened it earlier). 7. Move the throttle link up and down several times to make sure the carburetors open and close simultaneously. 8. Adjust the engine Idle Speed. IDLE SPEED + See Figures 266, 268 and 269 1. Be sure to check/set the Ignition Timing and Synchronize the Carburetors, before proceeding. 2. Mount the engine in a test tank or move the boat to a body of water. 3. Remove the cowling and connect a tachometer to the powerhead. 4. Start the engine and allow it to warm to operating temperature. 5. Check engine speed at idle. The powerhead should idle at the rpm specified in the Tune-up Specifications chart. 6. For all except Jet models, place the engine in gear and check engine trolling speed in the same manner. 7. If adjustment is necessary, shut down the powerhead. 8. Locate the carburetor pilot screws threaded horizontally into a boss at the top of the carburetor. Since each carburetor body contains 2 complete carburetor circuits, there are 2 pilot screws, one on either side, facing diagonally outward from their mounting bosses. Turn each of the carburetor pilot screws inward until it JUST lightly seats and then back out the specified number of turns, as indicated in the Carburetor Set-Up Specifications chart, found in the Fuel System section. 9. Loosen the throttle roller adjusting screw. Fig. 267 Throttle valve screws are leftˇhand thread Fig. 268 Carburetor pilot screws ˇ V4 and V6 Carbureted Motors 10. Start the engine and allow it to re-warm to operating temperature. Make sure the magneto control lever is in the idle position (withthe idle stopper contacting the crankcase, see Ignition Timing for clarification). 11. Rotate the idle adjust screw (not the pilot screw) until the powerhead idles at the required rpm. The idle adjustment screw is found on the rower (V4) or middle (V6) carburetor for these models and is threaded vertically downward, contacting the throHie valve linkage. Turning the screw INWARD will INCREASE idle speed, while backing it OUTWARD will DECREASE idle speed. 12. Retighten the throttle roller adjusting screw and check the Carburetor Pickup Timing. CARBURETOR PICKUP TIMING ADJUSTMENT + See Figures 269, 270 and 271 • Check/adjust the Ignition Timing, Carburetor Synchronization and Idle Speed prior to starting this procedure. 1. Start by checking the current adjustment by manually rotating the magneto control linkage counterclockwise so the idle stopper contacts the crankcase, then check that the mark on the throHle cam aligns with the center of the throttle roller. If so, no adjustment is necessary. If the roller and mark are not aligned, continue wit h the procedure. 2. Check and, if necessary, adjust the length of the throHie cam control link. The proper length varies by model, as follows: • SOJ-140 140 hp motors -2.09 in. (53mm) • 105J, all 150 hp motors (except 150G, D150H, P150TR or 0150 TR), all 175 hp motors (except 175F or P175TR) and all 200 hp motors (except 200G, S200F, LS200F, P200TR, S200TR or L200TR) -1.67 in. (42.5mm) • 150G, D150H, P150TR, D150 TR, 175F, P175TR, 200G, S200F, LS200F, P200TR, S200TR, L200TR and 225 hp motors -2.07 in. (52.5mm) 3. If necessary, disconnect the throHie cam control link, loosen the locknut and adjust the link to spec..ication, then retighten the locknut. Reconnect the link. 4. With the magneto control lever idle stopper still contacting the crankcase, loosen the throHie roller adjusting screw and reposition the linkage so the roller aligns with the mark on the throttle cam. Hold the roller in this position and retighten the adjusting screw. • If alignment cannot be achieved, loosen the locknut and adjust the length of the throttle cam control link. Tighten the locknut. MAINTENANCE & TUNE-UP 2-77 Throttle Roller Adjusting Screw Fig. 271 Throttle cam-to-throttle roller alignment is changed using the throttle roller adjusting screw (once the throttle control link Is set to a specific length) 2-78 MAINTENANCE & TUNE-UP -; -'ˇc CAUTION SetPin Fig. 273 Starter lockout adjustment -Manual Start V4 Motors Fig. 274 Oil pump link adjustment -V4 and V6 Motors ADJUSTING THE REMOTE CONTROL SHIFT CABLE + See Figure 272 Visually check the shift linkage movement in response to the shift handle. If the shifter does not engage properly or smoothly, adjust, as follows: 1. Remove the retaining clip and disconnect the shift cable joint from the powerhead linkage. 2. Loosen the shift cable joint locknut. 3. Set the remote control lever to the Neutral position. 4. Move the powerhead linkage set pin to align it with the Neutral mark on the lower cowling. 5. Adjust the position of the shift cable joint (by turning the joint inward oroutward on the cable threads) until its mounting hole aligns with the linkage set pin (while it is aligned with the Neutral mark on the cowling). Tighten the locknut to hold it in position on the cable. Make sure that after adjustment the cable joint is threaded over at LEAST 0.31 in. (8mm) of cable threads, otherwise there is a risk that the joint could separate in service causing a severe navigation/control hazard. 6. Position the cable joint over the control lever set pin and secure using the retaining clip. 7. Operate the control lever to confirm proper operation and smooth adjustment. • Be sure to follow the Ignition Timing and Synchronizing the Carburetors procedures before attempting to adjust the throttle cable. 1. Visually check the throttle cable adjustment by moving the remote throttle to the WOT position. Then check the magneto control lever to make sure it is touching the WOT stopper (for clarification, refer to the Ignition Timing procedure). If so, no further adjustment is necessary. However, if not, continue with the procedure to reset the throttle cable. 2. Loosen the locknut on the throttle cable joint, then remove the retaining clip and pull it from the set pin. 3. Move the remote throttle lever to the Neutral/Idle position. 4. Manually move the magneto control lever counterclockwise so the idle stopper contacts the crankcase. 5. Turn the cable joint inward or outward on the cable threads until it aligns with the set pin while both the remote throttle and the powerhead throttle lever are in the idle position. Then secure using the locknut. Make sure that after adjustment the cable joint is threaded over at LEAST 0.31 in. (8mm) of cable threads, otherwise there is a risk that the joint could separate in service causing a severe navigation/control hazard. 6. Install the cable joint back over the set pin and secure using the retaining clip. 7. Open and close the throttle a couple of times using the remote while visually checking to be sure the throttle valves on the carburetor open and close smoothly and to the full extent of their travel. If necessary, repeat the adjustment procedure. CHECKING/ADJUSTING THE STARTER LOCKOUT (MANUAL START + See Figure 273 Manual start models of this motor contain a starter lockout safety feature to prevent the motor from being started while in gear. The system should be checked at each tune-up to ensure that it is adjusted and functioning properly. Checking is a simple matter of placing the motor in gear and gently attempting to start the motor. If the starter will not rotate, the system is functioning and no further attention is required. However, if the motor rotates in gear, then adjust the cable as follows: 1. Begin with the engine not running and shifter positioned in Neutral. 2. Loosen the screw securing the cable adjusting plate to the starter housing. 3. Reposition the adjusting plate until the mark on the cable (a) aligns with the mark on the cam flywheel cover (b), then retighten the adjusting plate screw. 4. Verify that the lockout is now working properly. OIL PUMP LINK + See Figure 274 Obviously this adjustment is only for models equipped with the Yamaha Precision Blend automatic oil injection system. 1. Check the oil pump link adjustment by placing the throttle in the idle position and making sure that the oil pump lever is touching the stopper when the carburetor throttle valves are closed. If so, no further attention is necessary. However, if the pump lever is not in the correct position, continue with the procedure to adjust the link. 2. Remove the retaining clip and washer, then disconnect the control link from the oil pump. 3. Make sure the throttle valves are fully closed. If necessary, loosen the idle adjust screw (counting the number of turns so you can reposition it after the adjustment). 4. Loosen the oil control link locknut. 5. Hold the oil injection pump lever in the full-closed position, then adjust the control link length until the joint fits over the lever and tighten the locknut. 6. Reinstall the link onto the oil pump using the washer and retaining clip. 7. If you loosened the idle adjust screw, retighten it the same number of turns you counted earlier. Check and, if necessary, re-adjust the Idle Speed, as detailed earlier in this section. Fig. 272 Shift cable adjustment, aligning the set pin with the cowling mark-V4 and V6 Motors V6 EFI (OX66) and HPDI Motors SYNCHRONIZING THE THROTILE VALVES + See Figures 275, 276 and 277 . If the throttle is operating properly there isNO reason to perform this adjustment. Un-necessary tampering usually just leads to performance problems: Improper throttle valve adjustment will normally lead to an unstable idle. If necessary, remove the air intake silencer assembly and visually inspect the throttle valves to make sure that they open and close at the same ins_tants. If you can see signs that the throttle valves open unevenly, adjust the valve synchronization, as follows: • The throttle va.lve procedure for HPOI and 250 hp EFI Vmax models is a little more involved, not more difficult, but has a few more steps. Also, following the throttle valve adjustment on these models, unlike the other EFI motors, you should skip to Throttle Position Sensor Adjustment, and come back to Idle Speed afterwards. 1. If not done already, remove the air intake silencer for access. 2. Disconnect the throttle lever rod and, for the HPDI and 250 hp EFI Vmax, the oil pump rod. 3. Loosen the idle adjust screw until it is no longer touching the stopper. • For all EFI models, except the 250 hp Vmax, loosen the idle adjust screw only using full turns and count the number of turns outward to help resetting the idle screw after the throttle valves have been synchronized. 4. C..eck and make sure that all the throttle valves are now fully closed once the 1dle screw IS off the stopper. If so, no further adjustment is necessary. • On HPDI and 250 hp EFI motors It may be necessary to loosen the No. 4 throttle valve screw be!ore the throttle valves will be completely closed. Of course, at that pomt, you might as well finish the adjustment procedure. 1 -Throttle Valve Adjusting Screws Fig. 275 Throttle valve synchronization • V6 EFI Motors (except 250 Hp Vmax) MAINTENANCE & TUNE-UP 2-79 5. For EFI models, loosen the throttle valve adjusting screws for all cylinders EXCEPT No. 4. On the HPDI and 250 hp EFI Vmax, loosen All throttle valve adjusting screws, including the No. 4 valve screw. • Because the throttle valve screws have leftˇhand thread, they are loosened by turning CLOCKWISE. 6. Using gentle finger pressure, hold the No. 1 throttle valve in the fully closed position, then tighten the No. 1 throttle valve adjusting screw by turning it COUNTERCLOCKWISE. Repeat this step for cylinders No. 2, 3, 5, and 6...-For all EFI models except the 250 hp Vmax, turn the idle adjust screw back mward the same number of turns you counted when loosening it. On these models, you've finished the procedure. 8. For the HPDI and 250 hp EFI Vmax motors finish the procedure as follows: a. Reconnect the oil pump link rod. b. Turn the idle adjust screw back inward until the No. 4 throttle valve JUST starts to open, then tighten the screw an additional 1/2-1 turns. Fig. 276 Throttle valve synchronization •HPDI and 250 Hp EFI Vmax Motors Fig. 277 On all HPDI and the 250 Hp EFI Vmax, you'll also have to adjust the throttle lever rod length .. . ... ˇ. 2-80 MAINTENANCE & TUNE-UP c. Align the center of the throttle roller with the mark on the throttle cam, then tighten the No. 4 throttle adjusting screw by turning it COUNTERCLOCKWISE. d. Open and close the throttle valve 2ˇ3 times and double-check that the center of the roller is still aligned with the mark. e. For 3.3L HPDI models, connect a 3-pin test harness to the Throttle Position Sensor (TPS) wiring harness. Then turn the ignition switch ON and check the TPS output voltage across the Pink and Orange wires of the harness using a Digital Volt Ohmmeter (DVOM). Turn the idle adjust screw in or out as necessary until the TPS output is 0.58ˇ0.62 volts. In theory, you can skip the TPS adjustment procedure for this model since you've just checked/adjusted it now. f. Disconnect the throttle cable joint and adjust the lever rod to 6.2 in. (157mm) for EFI motors, 6.4 in. (163mm) for 2.5L HPDI motors or to 6.0 in. (151 .5mm) for 3.3L HPDI motors. Once the length is set, reconnect the cable joint. g. Install the air intake silencer and proceed to Throttle Position Sensor Adjustment before setting the Idle Speed. THROTTLE POSITION SENSOR ADJUSTMENT .Ž..+ See Figure 278 With each tune-up, or at least annually, you should check the Throttle Position Sensor (TPS) output voltage with the throttle valves fully closed. If the reading is out of specification, the physical positioning of the sensor can be adjusted in order to bring the reading into spec. However, the sensor does not generate a voltage, so much as the variable resistor within the sensor will change a reference signal from the Engine Control Module (ECM). Therefore, the circuit must be intact in order to test the sensor signal. You've got 2 options. One option is to attempt to back-probe the connector (insert the probes through the rear of the connector while it is still attached to the sensor). However this method risks damaging the connector or the wiring insulation (and could lead to problems with the circuit later). The better method is to disconnect the wiring harness and use 3 jumper wires (one for each terminal) to reconnect the harness. The jumpers must not contact each other (or you risk damage to the ECM from a short), however, some point on the jumper must be exposed so that you can probe the completed circuit using a DVOM. Yamaha makes 3-pin test harness for this application (#90890-06757). 1. Make sure the throttle valves are properly adjusted (check the Throttle Valve Synchronization) before proceeding. 2. If equipped, remove the flywheel cover for additional access. 3. If it is not still removed from checking the Throttle Valve Synchronization, remove the air intake assembly for access. 4. Disconnect the throttle link from the throttle valve for the No. 1 (top) throttle body. 5. Disconnect the wiring from the TPS and connect a test harness or jumper wires to complete the circuit. TPS Mount.ing I AdjustmentScrews Fig. 278 Throttle position sensor adjustment • V6 EFI and HPDI motors • The TPS sensor wiring is routed down the side of the powerhead, below the sensor itself (which is mounted adjacent to and connected to the top throttle body). Follow the harness from where it exits the sensor, down to the wiring harness connector, noting the routing for installation purposes. After testing, make sure the sensor wiring is safely tucked in the same position, to prevent possible damage from moving components. 6. Connect a Digital Volt Ohmmeter (DVOM) set to read DC votts to the Pink and Orange wires of the jumper/test harness. 7. Turn the ignition switch ON, then measure the output voltage with the throttle valves fully closed. The meter should show 0.48ˇ0.52 volts. 8. If the sensor voltage is out of range, loosen the 2 mounting screws and reposition the sensor (turn it slightly one direction or the other) to obtain the correct voltage readings. Once the sensor is properly repositioned, tighten the screws again to hold it in position. 9. Reconnect the throttle link to the top throttle body. 10. Operate the throttle valve 2ˇ3 times and double-check that the closed throttle voltage remains in spec. 11. For 3.3L HPDI motors, make sure the TPS voltage is 0.58ˇ0.62 with the throttle link connected to the top throttle body. If necessary, use the idle adjust screw to obtain the correct reading. 12. Check/adjust the Idle Speed, asdetailed earlier in this sect.ion. IDLE SPEED + See Figures 279and 280 .Ž • HOLD IT. On HPDI and 250 hp EFI Vmax models, the Throttle Position Sensor must be check.ed and/or adjusted before the idle speed. Refer to Throttle Position Sensor Adjustment before proceeding. 1. Be sure to check/set the Throttle Valve Synchronization and TPS Sensor Adjustment, before proceeding. 2. Mount the engine in a test tank or move the boat to a body of water. 3. Remove the cowling and connect a tachometer to the powerhead. 4. Start the engine and allow it to warm to operating temperature. 5. Check engine speed at idle. The powerhead should idle at the rpm specified in the Tune-up Specifications chart. 6. If applicable, place the engine in gear and check engine trolling speed in the same manner. • Yamaha does not provide a trolling engine speed spec for all EFI or HPDI models. Fig. 279 Before adjusting idle speed be sure to center the throttle roller••. c -slower Fig. 280 .••then turn the Idle adjust screw as necessary to obtain the desired idle 7. Check the alignment of the mark on the throttle cam and the throttle roller. If the roller is not centered on the mark, loosen the throttle valve adjust screw (ij is normally left-hand thread, meaning it would be loosened by turning CLOCKWISE) for the No. 4 cylinder. This screw is also known as the pickup adjustment screw. Reposition and align the mark on the throttle cam with the center of the throttle roller. • On the HPDI and 250 hp EFt Vmax models you really should have already accomplished this while Synchronizing the Throttle Valves, so just double-check the setting, and only readjust, if necessary. However, except of 3.3L HPDI models you should still loosen the screw slightly In order to properly adjust the idle speed. 8. Tum the idle adjust screw as necessary to obtain the correct idle speed. Turning the screw INWARD will INCREASE idle speed, while turning the screw OUTWARD will DECREASE idle speed. 9. Except for 3.3L HPDI motors, once the idle speed is set correctly, press down gently on the throttle control lever cam roller and, while holding it in this position, tighten the pickup adjustment screw. ADJUSTING THE REMOTE CONTROL SHIFT CABLE EFI Motors and Some 2.6L HPDI Motors + See Figure 272 This is the most common shift control cable configuration for EFI and HPDI motors. It is found on all EFI motors, as well as most 2.6L HPDI models including the Z150Q, VZ150, Z175H, VZ175 and some versions of the Z200TR, Z200NETO, LZ200TR and LZ200NETO models. If the linkage on your motors differs, follow the procedures for 2.6L HPDI Motors, Except Z150Q, VZ150, Z175H and VZ175 Models, found later in this section. Visually check the shift linkage movement in response to the shift handle. If the shifter does not engage properly or smoothly, adjust, as follows: 1. Remove the retaining clip and disconnect the shift cable joint from the powerhead linkage. 2. Loosen the shift cable joint locknut. Push Inward @mark Shift .. Push Outward@mark MAINTENANCE & TUNE-UP 2-81 3. Set the remote control lever to the Neutral position. 4. Move the powerhead linkage set pin to align it with the Neutral mark on the lower cowling. 5. Adjust the position of the shift cable joint (by turning the joint inward or outward on the cable threads) until its mounting hole aligns with the linkage set pin (while it is aligned with the Neutral mark on the cowling). Tighten the locknut to hold it in position on the cable. T-,k CAUTION Make sure that after adjustment the cable joint is threaded over at LEAST 0.31 in. (8mm) of cable threads, otherwise there is a risk that the joint could separate in service causing a severe navigation/control hazard. 6. Position the cable joint over the control lever set pin and secure using the retaining clip. 7. Operate the control lever to confirm proper operation and smooth adjustment. 2.6L HPDI Motors, Except Z1500, VZ150, Z175H and VZ175 Models + See Figures 281, 282 and 283 This procedure is for the alternate shift linkage used by certain 2.6L engines, except most Z150Q, VZ150, Z175H, VZ175 and some versions ol the Z200TR, Z200NETO, LZ200TR and LZ200NETO models. If the linkage on your motors differs, follow the procedures for EFI Motors and Some 2.6L HPDI Motors, found earlier in this section. Visually check the shift linkage movement in response to the shift handle. If the shifter does not engage properly or smoothly, adjust, as follows: 1. Remove the retaining clip and disconnect the shift cable joint from the powerhead linkage. 2. Loosen the shift cable joint locknut. 3. Move the remote control lever through Reverse, Neutral and Reverse several times, then set the remote control lever to the Neutral position. 4. Manually push the cable joint all the way inward and mark the position where the cable enters the cable casing. 5. Now manually pull the cable joint all the way outward and mark the position where the cable exists the casing. 6. At this point you'll have two lines on the cable, not all that far apart. These marks represent the amount of available cable free-play. Now make a third mark, centered right between the two, which will represent the center of the freeˇplay. 7. Gently push the cable back into the housing until the center free-play mark is right at the opening of the housing (meaning that the cable is centered in the middle of its free-play). 8. Manually position the shift rod set pin to the center of the slider bracket. There is a detent in the slider inline with a retaining screw and the set pin in this position. 9. Adjust the position of the shift cable joint (by turning the joint inward or outward on the cable threads) until its mounting hole aligns with the linkage set pin (while it is aligned with the center of the slider). Tighten the locknut to hold it in position on the cable. a-in mark b-out markc -Center of free play Marl( Slider Fig. 281 Make marks on the cable pushed inward and pulled outward•.• Fig. 282 ..•then make a mark centered between them, and push the cable inward to that mark Fig. 283 The slider bracket should be centered on the detent 2-82 MAINTENANCE & TUNE-UP Make sure that after adjustment the cable joint is threaded over at LEAST 0.31 in. (8mm) of cable threads, otherwise there is a risk that the joint could separate in service causing a severe navigation/control hazard. 10. Position the cable joint over the control lever set pin and secure using the retaining clip. 11. Operate the control lever to confirm proper operation and smooth adjustment. 3.3L HPDI Motors + See Figures 284 and 285 Visually check the shift linkage movement in response to the shift handle. If the shifter does not engage properly or smoothly, adjust, as follows: 1. Set the remote control lever to the Neutral position. 2. Remove the retaining clip and disconnect the shift cable joint from the powerhead linkage. 3. Loosen the shift cable joint locknut. 4. Manually move the powerhead linkage (shift lever) until the lever pin aligns with the line of the shift position switch plate (this is the Neutral position). 5. Now align the center of the set pin for the cable with the Neutral alignment mark on the lower cowling. 6. Adjust the position of the shift cable joint (by turning the joint inward or outward on the cable threads) until its mounting hole aligns with the linkage set pin (while it is aligned with the Neutral mark on the cowling). Tighten the locknut to hold it in position on the cable. Retaining Clip Shift Position Switch Plate Cable Joint Fig. 284 Adjust the shift lever until the lever pin aligns with the line of the shift position switch plate •3.3L HPDI Motors Fig. 285 Align the center of the set pin with the alignment mark on the lower cowling • 3.3L 11PDI Motors Make sure that after adjustment the cable joint Is threaded over at LEAST 0.31 in. (8mm) of cable threads, otherwise there is a risl< that the joint could separate in service causing a severe navigation/control hazard. 7. Position the cable joint over the control lever set pin and secure using the retaining clip. 8. Operate the control lever to confirm proper operation and smooth adjustment. + See Figures 286 and 287 • Be sure to follow the Synchronizing the Throttle Valve and Idle Speed adjustment procedures before attempting to adjust the throttle cable. 1. Check the throttle cable adjustment by moving the remote throttle to the Neutral/Idle position, then visually check the throttle valves in the throttle bodies to make sure they are fully closed. Slowly advance the throttle to WOT and check that the throttle valves open completely. If so, no further adjustment is necessary. However, if not, continue with the procedure to reset the throttle cable. 2. For HPDI and 250 hp EFI Vmax motors, loosen the locknut and throttle linkage stopper screw. 3. Loosen the locknut on the throttle cable joint, then remove the retaining clip and pull it from the set pin. 4. Move the remote throttle lever to the Neutral/Idle position. 5. Align the center of the throttle control lever cam roller with the alignment mark. 6. For HPDI and 250 hp EFJ Vmax motors, tighten throttle linkage stopper screw until it just contacts the throttle lever, then tighten the locknut. 7. Tum the cable joint inward or outward on the cable threads until it aligns with the set pin, then secure using the locknut. -o;;-'-CAUTION Make sure that after adjustment the cable joint Is threaded over at LEAST 0.31 in. (8mm) of cable threads, otherwise there is a risk that the joint could separate in service causing a severe navigation/control hazard. 8. Install the cable joint back over the set pin and securE! using the retaining clip. 9. Open and close the throttle a couple of times using the remote while visually checking to be sure the throttle valves open and close smoothly and to the full extent of their travel. If necessary, repeat the adjustment procedure. + See Figure 288 All EFI OX66 and HPDI motors utilize a Crankshaft Position Sensor (CPS) to provide information regarding engine positioning to the Engine Control Module (ECM). The sensor is used for fuel and ignition mapping purposes. Although all these motors use the sensor, only the HPDI models and the 250 hp EFI Vmax mention checking or adjusting the sensor position. This means that the either the gap is fixed on other EFI models and not adjustable, or this is just an oversight in the Yamaha service literature. If you have an EFI model, other than the 250 hp Vmax, you may want to locate the sensor and check for yourself if it is adjustable. If so, follow this procedure to check the gap. On all models with adjustable sensors, at least annually, doubleˇcheck the Crankshaft Position Sensor (CPS) gap. Remember that the proper gap must exist between the sensor and the flywheel in order for the HPDI or EFI system to work properly. Check the sensor adjustment by trying to insert a 0.02-0.06 in. (0.5- 1.5mm) feeler gauge between the sensor and the flywheel. When measuring a • Alignment mark ..ller ThrottleControl 8.0 mm (0.31 in)Fig. 286 Throttle cable adjustment ˇ V6 EFI Motors (except 250 hp Vmax models) a ˇAlignment Mark Joint MAINTENANCE & TUNE-UP 2ˇ83 a gap with a feeler gauge, remember that the gap is equal to the size gauge that will fit through the gap with a slight drag. The next larger size gauge should not fit, while the next smaller gauge should fit without touching or dragging. If adjustment is necessary, loosen the 2 CPS mounting screws and gently slide the sensor against a 0.02-0.06 in. (0.5-1.5mm) feeler gauge inserted between the flywheel and sensor. Tighten the mounting screws and double-check the gap using the gauge set. OIL PUMP LINK 1. Check the oil pump link adjustment by placing the throttle in the idle position and checking the positioning of the oil pump lever and stopper when the throttle valves are fully closed. On most models (except the 2.6L HPDI motors) there should be 0.04 in. (1mm) of clearance between the oil pump lever and the stopper, however on 2.6L HPDI motors the lever should be contacting the stopper. If so, no further attention is necessary. However, if • See Figure 289 CPS Mounting Screws Fig. 288 Crankshaft posi1ion sensor gap adjustment •HPDI and 250 hp EFI Vmax Motors Fig. 289 Oil pump link adjustment • EFI Motors 8.0 mm (0.31 in) Flg.287 Throttle cable adjustment -250 hp EA Vmax Motors the pump lever is not in the correct position, continue with the procedure to adjust the link. 2. Remove the retaining clip and washer, then disconnect the control link from the oil pump. 3. Make sure the throttle valves are fully closed. 4. Loosen the oil control link locknut. 5. For all except 2.6L HPDI motors, hold the oil injection pump lever gently against a 0.04 in. (1mm) feeler gauge inserted between the lever and the stopper, then adjust the control link length until the joint fits over the lever and tighten the locknut. 6. For 2.6L HPDI motors, hold the oil injection pump lever gently against the stopper, then adjust the control link length until the joint fits over the lever and tighten the locknut. 7. Reinstall the link onto the oil pump using the washer and retaining clip. 8. Double-check the gap (or lack thereof on 2.6L HPDI motors) between the lever and stopper using the feeler gauge. Readjust, if necessary. ---------- 2-84 MAINTENANCE & TUNE-UP IGNITION TIMING Ignition timing on these powerheads is adjusted (advanced/retarded) automatically by the Engine Control Module to match rpm operating conditions. Because there are no adjustments for timing, any problems or irregularities should be diagnosed and repaired as the result of defective mechanical or electrical components. No attempt should be made to perform adjustments in order to achieve the proper timing specifications, let the electronics do their job, but give them the tools that they need. STORAGE (WHAT TO DO BEFORE AND AFTER) Winterization + See Figure 290 Taking extra time to store the boat and motor properly at the end of each season or before any extended period of storage will greatly increase the chances of satisfactory service at the next season. Remember, that next to hard use on the water, the time spent in storage can be the greatest enemy of an outboard motor. Ideally, outboards should be used regularly. If weather in your area allows it, don't store the motor, enjoy it. Use it, at least on a monthly basis. It's best to enjoy and service the boat's steering and shifting mechanism several times each month. If a small amount of time is spent in such maintenance, the reward will be satisfactory performance, increased longevity and greatly reduced maintenance expenses. But, in many cases, weather or other factors will interfere with time for enjoying a boat and motor. If you must place them in storage, take time to properly winterize the boat and outboard. This will be your best shot at making time stand still for them. For many years there was a widespread belief simply shutting off the fuel at the tank and then running the powerhead until it stops constituted prepping the motor for storage. Right? Well, WRONG! First, it is not possible to remove all fuel in the carburetor or fuel injection system by operating the powerhead until it stops. Considerable fuel will remain trapped in the carburetor float chamber (or vapor separator tank of fuel injected motors) and other passages, especially in the lines leading to Fig. 290 Add fuel stabilizer to the system anytime It will be stored without complete draining However, most motors are equipped with a timing pointer and timing marks on the flywheel. If desired, you can use a timing light to confirm that the ECM is properly controlling timing. To do this, make sure the motor is either mounted in a test tank or the boat is launched as the motor must operate under load. Amays check the ign..ion timing with the motor fully warmed to normal operating temperature. For details on timing specifications, please refer to the TuneˇUp Specifications chart in this section. If the timing is out of specnication, double-check your procedures and test conditions, then suspect a fault w..h the ignition/fuel injection/engine management system. carburetors or injectors. The only guaranteed method of removing all fuel from a carbureted motor is to take the physically drain the carburetors from the float bowls. And, though you should drain the fuel from the vapor separator tank on most fuel injected motors, you still will not be able to remove all of it from the sealed high-pressure lines. Depending upon the leng1h of storage you can also use fuel stabilizer as opposed to draining the fuel system, but if the motor is going to be stored for more than a couple of months at a time, draining the system is really the better option. • Up here in the northeastern U.S., we always start adding fuel stabilizer to the fuel tank with every fuel fill up starting sometime in September. That helps to make sure that we'll be at least partially ˇprotected if the weather takes a sudden turn and we haven't had a chance to complete winterization yet. Proper storage involves adequate protection of the unit from physical damage, rust, corrosion and dirt. The following steps provide an adequate maintenance program for storing the unit at the end of a season. • If your outboard requires one or more repairs, PERFORM THEM NOW or during the offˇseason. Don't wait until the sun is shining, the weather is and you want to be back on the water. That's not the time to you have to of the gearcase and replace the seals. Don't put a motor that a repair into storage unless you plan on making the repair during the off-season. It's too easy to let it get away from you and it will cost you in down time next season. PREPPING FOR STORAGE Where to Store Your Boat and Motor Ok, a well lit, locked, heated garage and work area is the best place to store you precious boat and motor, right? Well, we're probably not the only ones who wish we had access to a place like that, but if you're like most of us, we place our boat and motor wherever we can. Of course, no matter what storage limitations are placed by where you live or how much space you have available, there are ways to maximize the storage site. If possible, select an area that is dry. Covered is great, even if it is under a carport or sturdy portable structure designed for off-season storage. Many people utilize canvas and metal frame structures for such purposes. If you've got room in a garage or shed, that's even better. If you've got a heated garage, God bless you, when can we come over? If you do have a garage or shed that's not heated, an insulated area will help minimize the more extreme temperature variations and an attached garage is usually better than a detached for this reason. Just take extra care to make sure you've properly inspected the fuel system before leaving your boat in an attached garage for any amount of time. If a storage area contains large windows, mask them to keep sunlight off the boat and motor otherwise, use a high-quality, canvas cover over the boat, motor and if possible, the trailer too. A breathable cover is best to avoid the possible build-up of mold or mildew, but a heavy duty, non-breathable cover will work too. If using a non-breathable cover, place wooden blocks or length's of 2 x 4 under various reinforced spots in the cover to hold it up off the boat's surface. This should provide enough room for air to circulate under the cover, allowing for moisture to evaporate and escape. Whenever possible, avoid storing your boat in industrial buildings or parks areas where corrosive emissions may be present. The same goes for storing your boat too close to large bodies of saltwater. Hey, on the other hand, if you live in the Florida Keys, we're jealous again, just enjoy it and service the boat often to prevent corrosion from causing damage. Finally, when picking a place tostore your motor, consider the risk or damage from fire, vandalism or even theft. Check with your insurance agent regarding coverage while the boat and motor is stored. Storage Checklist (Preparing the Boat and Motor) + See Figures 291 thru 294 The amount of time spent and number of steps IOuoweo m me storage procedure will vary with factors such as the length of planed storage time, the conditions under which boat and motor are to be stored and your personal decisions regarding storage. But, even considering the variables, plans can change, so be careful if you decide to perform only the minimal amount of preparation. A boat and motor that has been thoroughly prepared for storage can remain so with minimum adverse affects for as short or long a time as is reasonably necessary. The same cannot be said for a boat or motor on which important winterization steps were skipped. • If possible always store your Yamaha vertically on the boat or on a suitable engine stand. However, if you are to store a motor lying on its side, NO motor should be placed on its side until after ALL water has drained, otherwise water may enter a cylinder through an exhaust port causing corrosion (or worse, may become trapped in a passage and freeze causing cracks in the powerhead or Check your owner's manual for more details if you to store a motor on its side. However do store it this way, be sure to return the motor vertically a few before intended service and check the combustion chambers for oil before cranking the motor. 1. Thoroughly wash the boat motor and hull. Be sure to remove all traces of dirt, debris or marine life. Check the water stream fitting, water lnlet(s) and, on jet models, the impeller grate for debris. If equipped, inspect the speedometer opening at the leading edge of the gearcase ˇor any other gearcase drains for debris (clean debris with low-pressure compressed air or a piece of thin wire). • As the season winds down and you are approaching your last outing, start treating the fuel system then to make sure it thoroughlymixes with all the fuel in the tank. By the last outing of the season you should already have a protected fuel system. 2. Stabilize the engine's fuel supply using a high quality fuel stabilizer (of course the manufacturer recommends using Yamaha Fuel Conditioner and Stabilizer} and take this opportunity to thoroughly flush the engine cooling system at the same time as follows: a. Add an appropriate amount of fuel stabilizer to the fuel tank (for Yamaha stabilizer it is normally one ounce for each gallon of untreated fuel) MAINTENANCE & TUNE-UP 2-85 and top off to minimize the formation of moisture through condensation in the fuel tank. b. Attacfl a flushing attachment as a cooling water/flushing source. For details, please refer to the information on Flushing the Cooling System, in this section. c. Start and run the engine at fast idle approximately 1 0ˇ15 minutes. This will ensure the entire fuel supply system contains the appropriate storage mixtures. .:.ˇor-ˇ WARNING Yamaha warns not to use a fogging oil that contains Silicon, Phosphorus or Lead on EFI or HPDI motors that are equipped with an oxygen sensor. Also, although you could use a Silicon based spray on external components for these motors, be sure not to spray it near the air intake or the oxygen sensor to prevent possible damage. If you are uncertain whether or not your motor contains an oxygen sensor, please refer to the Fuel System section or the Wiring Diagrams in the Ignition and Electrical System section. d. Just prior to stopping the motor fog the engine using Yamaha Storˇ Rite Engine Fogging Oil (or equivalent fogging spray). Spray the oil alternately into each of the carburetor or throttle body (EFI or HPDI) throats (you'll likely have to remove an air intake silencer/flame arrestor for access). When properly fogged the motor will smoke excessively, will stumble and will almost stall. e. Stop the engine and remove the flushing source, keeping the outboard perfectly vertical. Allow the cooling system to drain completely, especially if the outboard might be exposed to freezing temperatures during storage. ..-* WARNING NEVER keep the outboard tilted when storing in below-freezing temperatures as water could remain trapped in the cooling system. Any water left in cooling passages might freeze and could cause severe engine damage by cracking the powerhead or gearcase. 3. Drain and refill the engine gearcase while the oil is still warm (for details, refer to the Gearcase Oil procedures in this section). Take the opportunity to inspect for problems now, as storage time should allow you the opportunity to replace damaged or defective seals. More importantly, remove the old, contaminated gear oil now and place the motor into storage with fresh oil to help prevent internal corrosion. 4. Finish fogging the motor manually through the spark plug ports as follows: a. Tag and disconnect the spark plug leads, then remove the spark plugs as described under Spark Plugs. b. Spray a generous amount of fogging oil into the spark plug ports. Yamaha recommends a 5-10 second long spray of their Yamaha Stor-Rite Engine Fogging Oil for each cylinder. Fig. 291 Be sure to fog the motor through the spark plug ports ... Fig. 292 . ..and drain the carb float bowls before storage Fig. 293 Multiple carburetors will mean multiple float bowls to drain 2ˇ86 MAINTENANCE & TUNE-UP Vapor Separato Tank Fig. 294 HPDI and some EFI motors have a drain plug on the vapor separator tank, just like carburetor float bowls, they should be drained IllOn most Yamaha motors you can disable the ignition system by leaving the safety lanyard disconnected but still use the starter motor to tum the motor. This is handy for things like compression tests or distributing fogging oil. To be certain use a spark plug gap tester on one lead and crank the motor using the keyswitch. If no spark is present, you're good to go. c. Turn the flywheel slowty by hand (clockwise, in the normal direction of rotation) to distribute the fogging oil evenly across the cylinder walls. On electric start models, the starter can be used to crank the motor over in a few short bursts, but make sure the spark plugs leads remain disconnected and grounded to the powerhead (away from the spark plug ports) to prevent accidental combustion. If necessary, re-spray into each cylinder when that cylinder's piston reaches the bottom of its travel. Reinstall and tighten the spark plugs, but leave the leads disconnected (and GROUNDED) to prevent further attempts at starting until the motor is ready for re-commissioning. mOn motors equipped with a rope start handle, the rope can be used to turn the motor slowly and carefully using the rope starter. For other models, turn the flywheel by hand or using a suitable tool, but be sure to ALWAYS turn the engine In the normal direction of rotation (normally clockwise on these motors). Also, keep in mind that the flywheel on most Yamaha outboards (even electric start models) Is notched to accept an emergency starter rope. You can always use a knotted rope Inserted Into the notch and wound around the flywheel to help turn it. 5. On carbureted motors, if the motor is to be stored for any length of time more than one off-season you really MUST drain the carburetor float bowls. Honestly, it is a pretty easy task and we'd recommend doing that for all motors, even if they are only going to be stored for a few months. To drain the float bowls locate the drain screw on the bottom of each bowl, place a small container under the bowl and remove the screw. Repeat for the remaining float bowls on multiple carburetor motors. 6. On EFI or HPDI motors, if the vapor separator tank contains a drain screw, it is a good idea to completely drain the tank of fuel. This will help protect the fuel lines and components in the tank from possible damage by deteriorating fuel. 7. For models equipped with portable fuel tanks, disconnect and relocate them to a safe, well-ventilated, storage area, away from the motor. Drain any fuel lines that remain attached to the tank. It's a tough call whether or not to drain a portable tank. Plastic tanks, drain em' and burn the fuel in something else. Metal tanks, well, draining them will expose them to mo!sture and possible corrosion, while topping them off will help prevent this, so tt probably makes more sense to top them off with treated fuel. 8. Remove the battery or batteries from the boat and store in a cool dry place. If possible, place the battery on a smart charger or Battery TendetŽ, otherwise, trickle charge the battery once a month to maintain proper charge. Remember that the electrolyte in a discharged battery has a much lower freezing point and Is more likely to freeze (cracking/destroying the battery case) when stored for long periods in areas exposed to freezing temperatures. Although keeping the battery charged offers one level or protection against freezing; the other is to store the battery in a heated or protected storage area. 9. For models equipped with a boat mounted fuel filter or filter/water canister, clean or replace the boat mounted fuel filter at this time. If the fuel system was treated, the engine mounted fuel filters should be left intact, so the sealed system remains filled with treated fuel during the storage period. 10. For motors with external oil tanks, if possible, leave the oil supply line connected to the motor. This is the best way to seal moisture out of the system. If the line must be disconnected for any reason (such as to remove the motor or oil tank from the boat), seal the line by sliding a snug filling cap over the end. 11. Perform a complete lubrication service following the procedures in this section. 12. Except for Jet Drive models, remove the propeller and check thoroughly for damage. Clean the propeller shaft and apply a protective coating of grease. 13. On Jet models, thoroughly inspect the impeller and check the Impeller clearance. Refer to the procedures in this section. 14. Check the motor for loose, broken or missing fasteners. Tighten fasteners and, again, use the storage time to make any necessary repairs. 15. Inspect and repair all electrical wiring and connections at this time. Make sure nothing was damaged during the season's use. Repair any loose connectors or any wires with broken, cracked or otherwise damaged insulation. 16. Clean all components under the engine cover and apply a corrosion preventative spray. 17. Too many people forget the boat and trailer, don1 be one of them. a. Coat the boat and outside painted surfaces of the motor w..h a fresh coating of wax, then cover it with a breathable cover b. If possible place the trailer on stands or blocks so the wheels are supported off the ground. c. Check the air pressure in the trailer tires. If it hasn't been done in a while, remove the wheels to clean and repack the wheel bearings. 18. Sleep well, since you know that your baby will be ready for you come next season. Re-Commissioning REMOVAL FROM STORAGE The amount of service required when re-commissioning the boat and motor after storage depends on the length of non-use, the thoroughness of the storage procedures and the storage conditions. At minimum, a thorough spring or pre-season tune-up and a full lubrication service is essential to getting the most out of your engine. If the engine has been properly winterized, it is usually no problem to get it in top running condition again in the springtime. If the engine has just been put in the garage and forgotten for the winter, then it is doubly important to perform a complete tune-up before putting the engine back into service. If you have ever been stranded on the water because your engine has died andyou had to suffer the embarrassment of having to be towed back to the marina you know how it can be a miserable experience. Now is the time to prevent that from occurring. • Although you should normally replace your spark plugs at the beginning of each season, we like to start and run the engine (for the compression check) using the old spark plugs. Why? Well, on that start-up you're going to be burning off a lot of oil, why expose the new plugs to it? Besides you have to remove the in order to perform the tune-up compression check anyway so you can Install the new ones at that time. Take the opportunity to perform any annual maintenance procedures that were not conducted immediately prior to placing the motor into storage. If the motor was stored for more than one off-season, pay special attention to inspection procedures, especially those regarding hoses and fillings. Check the engine gear oil for excessive moisture contamination. The same goes for oil tanks on 2-strokes, so equipped. If necessary, change the gearcase or engine oil to be certain no bad or contaminated fluids are used. • Although not absolutely necessary, it is a good idea to ensure optimum cooling system operation by replacing the water pump impeller at this time. Impeller replacement was once an annual ritual, we now hear that most impellers seem to do well for 2-3 seasons, and some more. You'll have to make your own risk assessment here, but keep an eye on your cooling indicator stream get to know how strong the spray looks (and how warm it feels) to help you make your decision. Other items that require attention include: 1. Install the battery (or batteries) if so equipped. 2. Inspect all wiring and electrical connections. Rodents have a knack for feasting on wiring harness insulation over the winter. If any signs of rodent life are found, check the wiring carefully for damage, do not start the motor until damaged wiring has been fixed or replaced. 3. On motors with a remote oil tank, if the line was disconnected, remove the cover and reconnect the line, then prime the system to ensure proper operation once the motor is started. • The Precision Blend oiling system is normally equipped with a manual priming switch/button. On other models it will be necessary to run the engine on a separate pre-mix tank while the Precision Blend oiling line is disconnected from the engine to bleed air from the line and prime the system. Please refer to your owner's manual or to the Lubrication and Cooling section for more details. CLEARING A SUBMERGED MOTOR Unfortunately, because an outboard is mounted on the exposed transom of a boat, and many of the outboards covered here are portable units that are mounted and removed on a regular basis, an outboard can fall overboard. Ok, it's relatively rare, but it happens often enough to warrant some coverage here. The best way to deal with such a situation is to prevent it, by keeping a watchful eye on the engine mounting hardware (bolts and/or clamps). But, should it occur, here's how to salvage, service and enjoy the motor again. In order to prevent severe damage, be sure to recover an engine that is dropped overboard or otherwise completely submerged as soon as possible. It is really best to recover it immediately. But, keep in mind that once a submerged motor is recovered exposure to the atmosphere will allow corrosion to begin etching highly polished bearing surfaces of the crankshaft, connecting rods and bearings. For this reason, not only do you have to recover it right away, but you should service it right away too. Make sure the motor is serviced within about 3 hours of initial submersion. OK, maybe now you're saying "3 hours, it will take me that long to get it to a shop or to my own garage." Well, if the engine cannot be serviced immediately (or sufficiently serviced so it can be started), re-submerge .. in a tank of fresh water to minimize exposure to the atmosphere and slow the corrosion process. Even if you do this, do not delay any more than absolutely necessary, service the engine as soon as possible. This is especially important if the engine was submerged in salt, brackish or polluted water as even submersion in fresh water will not preserve the engine indefinitely. Service the engine, at the MOST within a few days of protective submersion. After the engine is recovered, vigorously wash all debris from the engine using pressurized freshwater. • If the engine was submerged while still running, there Is a good chance of internal damage (such as a bent connecting rod). Under these circumstances, don't start the motor, follow the beginning of this procedure to try turning it over slowly by hand, feeling for mechanical problems. If necessary, refer to Powerhead Overhaul for complete disassembly and repair instructions. NEVER try to start a recovered motor until at least the first few steps (the ones dealing with draining the motor and checking to see it if is hydro-locked or damaged) are performed. Keep in mind that attempting to start a hydro-locked motor could cause major damage to the powerhead, including bending or breaking a connecting rod. MAINTENANCE & TUNE-UP 2-87 4. If not done when placing the motor into storage clean and/or replace the fuel filters at this time. • Portable fuel tanks should be emptied and cleaned using solvent Take the opportunity to thoroughly inspect the condition of the tank. For more details on fuel tanks, please refer to the Fuel System section. 5. If the fuel tank was emptied, or if it must be emptied because the fuel is stale fill the tank with fresh fuel. Keep in mind that even fuel that was treated with stabilizer will eventually become stale, especially if the tank is stored for more than one offˇseason. Pump the primer bulb and check for fuel leakage or flooding at the carburetor. 6. Attach a flush device or place the outboard in a test tank and start the engine. Run the engine at idle speed and warm it to normal operating temperature. Check for proper operation of the cooling, electrical and warning systems. :;' ˇˇ CAUTION Before putting the boat in the water, take time to verify the drain plug is installed. Countless number of spring boating excursions have had a very sad beginning because the boat was eased into the water only to have the boat begin to fill with it. If the motor was submerged for any length of time it should be thoroughly disassembled and cleaned. Of course, this depends on whether water intruded into the motor or not. Check the gearcase oil (on all motors) for signs of contamination. The extent of cleaning and disassembly that must take place depends also on the type of water in which the engine was submerged. Engines totally submerged, for even a short length of time, in salt, brackish or polluted water will require more thorough servicing than ones submerged in fresh water for the same length of time. But, as the total length of submerged time or time before service increases, even engines submerged in fresh water will require more attention. Complete powerhead disassembly and inspection is required when sand, silt or other gritty material is found inside the engine cover. Many engine components suffer the corrosive effects of submersion in salt, brackish or polluted water. The symptoms may not occur for some time after the event. Salt crystals will form in areas of the engine and promote significant corrosion. Electrical components should be dried and cleaned or replaced, as necessary. If the motor was submerged in salt water, the wire harness and connections are usually affected in a shorter amount of time. Since it is difficult (or nearly impossible) to remove the salt crystals from the wiring connectors, ij is best to replace the wire harness and clean all electrical component connections. The starter motor, relays and switches on the engine usually fail if not thoroughly cleaned or replaced. To ensure a thorough cleaning and inspection: 1.Remove the engine cover and wash all material from the engine using pressurized freshwater. If sand, silt or gritty material is present inside the engine cover, completely disassemble and inspect the powerhead. 2. Tag (except on single cylinder motors) and disconnect the spark plugs leads. Be sure to grasp the spark plug cap and not the wire, then twist the cap while pulling upward to free it from the plug. Remove the spark plugs. For more details, refer to the Spark Plug procedure in this section. 3. Disconnect the fuel supply line from the engine, then drain and clean all fuel lines. Depending on the circumstances surrounding the submersion, inspect the fuel tank for contamination and drain, if necessary. -"'"+ WARNING When attempting to turn the flywheel for the first time after the submersion, be sure to turn it SLOWLY, feeling for sticking or binding that could indicate internal damage from hydro-lock. This is a concern, especially if the engine was cranked before the spark plug(s) were removed to drain water or if the engine was submerged while still running. 2-88 MAINTENANCE & TUNE-UP 4. Support the engine horizontally with the spark plug port(s) facing downward, allowing water, if present, to drain. Force any remaining the water out by slowly rotating the flywheel by hand about 20 times or until there are no signs ofwater. If there signs of water present, spray some fogging oil into the spark plug ports before turning the flywheel. This will help dislodge moisture and lubricate the cylinder walls. 5. On carbureted models, drain the carburetor(s). The best method to thoroughly drain/clean the carburetor is to remove and disassemble it, but thefloat bowl drain screws are pretty accessible on Yamahas and this is not absolutely necessary. It's not a bad idea to spray some fogging oil into the carburetors to make sure moisture is displaced. The oil will burn once the motor is started anyway. For more details on carburetor service refer to the Carburetor procedures under Fuel System. 6. Support the engine in the normal upright position. Check the engine gearcase oil for contamination. Refer to the procedures for Gearcase Oil in this section. The gearcase is sealed and, if the seals are in good condition, should have survived the submersion without contamination. But, if contamination is found, look for possible leaks in the seals, then drain the gearcase and make the necessary repairs before refilling it. For more details, refer to the section on Gearcases. SPECIFICATIONS 7. On motors with an injection oil tank mounted TO the motor, drain the oil and dispose of it properly. Don't risk your engine with potentially contaminated oil. Clean the tank using solvent and drain, then refill the tank with fresh, clean 2-stroke oil. 8. Remove all external electrical components for disassembly and cleaning. Spray all connectors with electrical contact cleaner, then apply a small amount of dielectric grease prior to reconnection to help prevent corrosion. For electric start models, remove, disassemble and clean the starter components. For details on the electrical system components, referto the Ignition and Electrical section. 9. Reassemble the motor and mount the engine or place it in a test tank. Start and run the engine for 1/2 hour. If the engine won't start, remove the spark plugs again and check for signs of moisture on the tips. If necessary, use compressed air to clean moisture from the electrodes or replace the plugs. 10. Stop the engine, then recheck the gearcase oil and injection oil tank, if equipped. 1t. Perform all other lubrication services. 12. Try not to let it get away from you (or anyone else) again! TUNE-UP SPEC/FICAT/ONS CHARTˇ 2-Stroke Motors SporlcPivg lgn/tiotl ldloSpHd TesiPtopolltrModel Engine Tltrotn. HowEitjj/M (Hp) ofCy1 Chomp/on CnPkkup Trolling 2.6(43) 0.024-0.028 (0.6.0. 7) 0.024-0.0 8 (0.6ˇ0.7) 0.035.().039(0.9ˇ1.0) 0.024-0.028 (0.6.().7} 6.3(103) 0.02 -0.028 (0.6.0. 7} 6.3(103) 0.024-0.028 (0.6.0. 7} 10(165) 10(165) 15(246) 0.035.o.039 (0.9ˇ1.0) 0.035.().039 (0.9-1.0) 0.035.o.039 (0.9-1.0) 0.02 -0.28 (0.6-0.7} 26(430) 0.024-0.28 (0.6-0.7} 87HS-10 Ž 0.035.o.039 (0.9-1.0} BIJHS-10 Ž 0.035.().039 (0.9-1.0)36(592) 0.024-0.28 (0.6-0.8} 48 (760) 0.024-028 (0.6.0.8} 30(496) BlHS-10 Ž 0 035.0.039 (0.9-1.0) 30 (496) 0.035ˇ0.039 (0.9ˇ1.0) 43(698) 0.035.0.039 (0.9-1.0} 43 (69 ) 0.035.0.039 (0.9-1.0} 43(698) BlHS-10 Ž 0.035.().039 (0.9-1.0) 43(6 8) 0.035-0.039 (0.9-1.0) 0.035ˇ0.039 (0.9-1.0}0.035.(),039(0.9-1.0}0,035.(),039(0.9ˇ1.0} 70(1140) 0.035.o.039 (0.9-1.0} BBHS-10 @ 0.035.0.039 (0.9-1.0)70(1140) BBHS-10 @ 0.035-0.039 (0.9-1.0} BBHS-10 @ 0.035.().039 (0.9-1.0) BBHS-10 @ 0.035.().0 (0.9ˇ1.0) 106(1730) 0 035.().039 (0.9ˇ1 0) MAINTENANCE & TUNE-UP 2ˇ89 TUNE-UP SPEC/FICAT/ONS CHART ˇ 2-Stroke Motorssp.ncPlc#f lgn/11011 ldltSf>H'IMoct.l No. Engine Displace GIIP Tlllllng.. RPII(Hp) ofCyl Type YNr ell. in. (cc) NGK ,. Pictup Ntulrol Trolling 12 \'8-16 6 9ATDC t9(CĨ111 610.730 12 4500-5500 ..SpecificaCionisfotUSAModol•.lhe manllocturĢracommendsuH1gnoiHsupprtsSOflyptplug NGKBR7HS lorConac!a andEurope..Spec:ificedplugisfo< atexceptEurope.nd Cancla-.111em;onulacMe< recommend> the rosi-lypepii!Q BR7HS-10fotthis..@SptcifiCation isforaloxctpl 1996Canada modo!$ whichshouldbe 750-810rpm ..Specilfcation isforaBeJO:epiCanadaandEuropeforwhichthe manufac1urer recommends using roslstctlype plug BR7HSˇ10GilSpocif.ealionisfotaUexcep1 Canada. Europa,and SocAhAfricaforwhich tt>omanufac1ureSpecification1$5300.5500rpmthrough1998or5000-5200rpmfor 1999andIIIIerrtype plug BR8HSˇ10Isalsoavailablefortills application andisoften•pecifiedloruse oUI$1dothoU.S.In EuropeandCanadaŽSpoclflcallonI•6-8ATOCfounos1models,..orthe1999ESOwhichshooldbesollo 1ˇ3ATOCGSpcc.iflcationis21ˇ23BTDCforallmo!Ors,oxcoptfotESOmodelsforwhich tho WOTI/mlngshould bosot lo 18-20BTOC0Speclflutionb 7..IdleI55().650 trolling onmost mo40rs. except forESOmodelsforwhichthotrollingspeed shouldbe850-900 rpm.Also, nOitlhaltho1999E90 Idle should bosetto 1000rpmGSpecificalionis 7..SATOCJdleand camplckupformostmodelsincluding C7SondP75.h.-rspecs fO< the E75are1..JBTOCidleand campickupforE75modelsSSpecificationis19-21 BTDCformostrnolor$,includingallC75& P75.butspecs forEendAmodo!$shouldbe Milo 21ˇ238TOCoxceptfot E..specmolors whichshou!dalsobo 19-21 BTOC eSpecificationis 4800-5500 fotmostmolors,lncludlngolC75andP75.b<4E andAmodelsshooldbo47sa-.9504bSpeciflcalion24-26BTOCfotmostmolors. oxcoptlha E115AforwhichlulladVance6mingshouldbosottD22-24 BTDC•sptdtlc:a:Jonisfor mD$1corburiCed 150 hpm*". oxcepllho0150...tlichuws theNGK plug BR7HS-10otCl>ampionplugQUI2C .nd the C1..whlc:hUHS Champion 83HS-10orNGKL82C especificalionisfotrnosl.. 1..hpmotors.oxcept1he0150.1'150forwhlcltoro21ˇ258TOC,IhoV150whichis19-21 .,lho C150whichis 1&-.20BTOC 60Spodflcationis fottheS175,WOT fmingforthe P175shouldbe Srsare1ˇ7BTOC0SpecificationIslistedinfactoryseNico manual,butfactoryIIJn•upguict.Hsls difl'orontplugsbasedonengine..rtalnumbersas loHows:Z175 00101-1100231,and V2175800105-800201 useBt eWJ/y 100hours ando/fseasott Since many lwfers uselheirC1atsleu /han 100hours a yea, theseilems should:i.sl bepelfolmedii/IIIU>I/y.ll youlinrJyoursedriglt >I'OW'Id 100 IIOJJrs petse;nOJt ..y tolimeltlesemcssogcx:curs nmedim/ypriOIIopfaclngltlemoltJt insfotage. as sane items must be rep61fom>ed If/he eng/fltlisusedagain(evenOflee} belotestllage. cģReccrtrfltlnd. •""' r8f)artllng IJte need to ..us/the caF!wre/or(as opposedfo on/ycl>e"Jeidorcmlb:ase IKl4s onlhe 2Wm 4ˇslro10 mo/Dts ŽFormodels that use rep/ace>ble61/etelemer*> /he repJactmed. /nletrdoiEVERY dafs use and evetY 10 hOllr. AlsQ every :ill IIOJJrs replacethe gtease wing the s. lublicalion .. bulidenopeta/ed onieWedgasoline, lttenfnspecJioti..ustnenl inllllral should be redUced ID300IIOJJrs/2 years) ŽWaistfJII7IfJh>ptJilelinspec/JM..s vatyfranno spec(mos/C1:1T7TIOO). Io inspecleWJI)' 100 IIOJJis (mos/4ˇs9 orreplactJeWJiffJ(J()hour$130mMhs (201Y22!J hp 4-$9 MAINTENANCE & TUNE-UP 2-91 G en era IE s f"fipec1 1ca aons -2 St -roke Mo ors t H Model No. Engine Stroke Compression Weight ( p) of Cyl Type Year cu. in. (cc) ln. (mm) Ratio lb. (kg) * 2 1 IL 2-stroke 1997-02 2.6 1 .54 X 1.42 39 X 36 7.4:1 22 2 1 IL 2-stroke 1997-02 3.0 1.65 X 1.42 42 X 36 8.3:1 21.6 3 1 IL 2-stroke 1997-02 4.3 1.81 X X 6.9:1 4 1 CL 2-stroke 1992-99 5.0 1.97x 1.65 7.0:1 45-47 4 1 CL 2-stroke 1997-02 6.3 2.13 X 1.77 54 X 6.5:1 46-47 5 1 CL 2..stroke 1997-02 6.3 2.13 X 1.77 X 6.5:1 45-46 6 2 CL 2-stroke 1997-00 10 1.97 X 1.65 X 42 7.0:1 60-65 8 2 CL 2-stroke 1997-03 10 1.97 X 1.65 X 7.0:1 60..5 2 IL 2-stroke 1997-03 15 2.20 X 1.97 X 6.8:1 80-86 2 IL 2-stroke 1997-03 15 2.20 X 1.97 X 6.8:1 15 80-86 20 2 IL 2-stroke 1997 24 395 2.64 X 2.20 X 7.2:1 106-108 25 2 IL 2-stroke 1997-03 2.64 X 2.20 X 7.2:1 111-115 20 2 IL 2-stroke 1997-98 26 430 2.64 X 2.40 67 X 6.6:1 109 25 2 IL 2-stroke 1997-98 26 430 2.64 X 2.40 X 7.0:1 106-112 25 2 IL 2-stroke 1997 30 496 2.83 X 2.40 72 X 61 6.2:1 115-122 30 2 IL 2-stroke 1997 30 496 2.83 X 2.40 72 X 61 7.0:1 115-126 2 IL 2-stroke 1997 36 592 2.95 X 2.64 75 X 67 6.5:1 133-165 48 2 IL 2-stroke 1997-00 46 760 3.20 X 2.80 X 6.5:1 183-187 25 3 IL 2-stroke 1997-02 30 496 2.34 X X 6.8:1 130-146 59-66 30 3 IL 2-stroke 1997-02 30 2.34 X 2.34 X 6.8:1 130-148 28J 3 IL 2-stroke 1997-01 698 2.64 x2.60 67 x66 6.0:1 158 40 43 698 3 IL 2-stroke 698 2.64 x 2.60 67 x66 6.0:1 1701997-01 3 IL 2-stroke 1997-03 2.64 x2.60 67 x66 6.0:1 162-208 3 IL 2-stroke 1997-03 43 2.64 X X 6.0:1 158-202 3 IL 2-stroke 1997-03 2.83 X 2.74 X 6.33:1 50 225 60 3 IL 2-stroke 1997-03 52 2.83 X 2.74 X 6.1:1 207-247 70 3 IL 2-stroke 1997-03 52 2.83 X 2.74 X 6.1:1 Ž 207-247 65J 3 IL 2-stroke 1997-01 3.23 X 2.83 X 4.5:1 247-267 3 IL 2-stroke 1997-00 70 1140 3.23 X 2.83 X Ž 245-277 111-126 3.23 X 2.83 82 X3 IL 2-stroke 1997-00 70 1140 5.9:1 266-272 121-124 80 85 3 IL 2-stroke 1997-00 70 1140 3.23 X 2.83 82 X 72 5.1:1 245-273 111-124 3 IL 2-stroke 1997-03 70 1140 3.23 X 2.83 82 X 72 5.86:1 246-277 80J 4 90 LV 2-stroke 1997-98 106 1730 3.54 X 2.68 90 X 68 6.7:1 340 4 90 LV 2-stroke 1999-01 106 1730 3.54 X 2.68 90 x68 6.5:1 340 100 4 90 LV 2-stroke 1997-98 106 3.54 X 2.68 90x68 6.5:1 368 167 4 90 LV 2-stroke 1999-02 106 3.54 x2.68 90 x68 6.8:1 368 167 115 4 90 LV 2-stroke 1997-03 106 3.54 X 2.68 X 68 6.5:1 @ 322-377 130 4 90 LV 2-stroke 1997-03 106 3.54 X 2.68 X 6.8:1 364-373 140 4 90 LV 2-stroke 1997-98 106 3.54 X 2.68 X 6.5:1 340-353 4 90 LV 2-stroke 1999-02 106 3.54 X 2.68 X 6.8:1 340-353 105J 6 90 LV 2-stroke 1997-00 158 3.54 X 2.68 X 6.2:1 398 150 6 90 LV 2-stroke 1997•03 158 3.54 X 2.68 X Ž 392-467 6 90 LV 2-stroke 1997-00 158 3.54 X 2.68 X 68 Ž 392-437 178-198 6 90 LV 2-stroke 1997-03 158 3.54 X 2.68 90 X 68 Ž 200 392-467 225 6 90 LV 2-stroke 1997 3.54 X 2.68 90 X 6.4:1 397-437 180-198 150 HPDI 6 76 LV 2-stroke 380 (70) 124 minutes 50 3 IL 2-stroke. 1997..3 52 (849) PB or50:1 PM COl Micro Electric Carb 380 (70) 124 minutes60 3 IL 2-stroke 1997-CJ3 52 (849) PB or50:1 PM COl Micro Electric Catb 380 (70) 124 minutes 70 3 IL 2-stroke 1997..3 52 (849) PB or50:1 PM COl Micro Electric Catb 380 (70) 124 minutes 3 IL 2..stroke 1997..1 70(1 140) PBor50:1 PM COl Micro Manual and/or flee Carb 380 (70) 124 minutes 75 3 IL 2-stroke 1997..0 70 (1140) PB or50:1 PM @) Manual and/or Elec Carb 380 (70) 124 minutes 80 3 IL 2-stroke 1997.. 70 (1140) Precision Blend CDI Micro Electric cam 380 (70) 124 minutes 85 3 IL 2-stroke 1997-00 70 (1140) P8 or 50:1 PM CDI Micro Manual and/or E/ec Cam 380 (70) 124 minutes 3 IL 2-stroke 1997..3 70 (1140) PB or 50:1 PM CDI Micro Electric cam 380 (70) 124 minutes 4 90 LV 2-stroke 1997..1 106 (1730) Precision Blend COl Electric Catb 380 (70) 124 minutes 100 4 90 LV 2-stroke 1997..2 106 (1 730) Precision Blend COl Electric Catb 380 (70) 124 minutes 115 4 90 LV 2-stroke 1997..3 106 (1 730) PB or50:1 PM CDI Electric Catb 380 (70) 124 minutes 130 4 90 LV 2-stroke 1997..3 106 (1 730) Precision Blend COl Electric Carb 380 (70) 124 minutes 140 4 90 LV 2-stroke 1997..2 106 (1730) PB or50:1 PM COl Electric Catb 380 (70) 124 minutes 105J 6 90 LV 2-stroke 1997.. 158 (2596) Precision Blend COl Micro Electric 380 (70) 124 minutes 150 6 90 LV 2-stroke 1997..3 158 (2596) PB or 50:1 PM Ž Electric Carll or EFt 380 (70) 124 minutes 175 6 90 LV 2-stroke 1997.. 158 (2596) P8 or 50:1 PM CDI Micro Electric Catb 380 (70) 124 minutes200 6 90 LV 2-stroke 1997-CJ3 158 (2596) PB or 50:1 PM COl Micro Electric Carb orEFI 380 (70) 124 minutes 225 6 90 LV 2-stroke 1997 158 (2596) P8 or 50:1 PM CDI Micro Carb 360 (1 00) 124 minutes 150HPDI 6 76 LV 2-stroke 2000..3 158 (2596) Precision Blend TCI Micro Electric 360 (100) 124 minutes •-..ˇ +..-• : •• ;. : 2ˇ94 MAINTENANCE & TUNE-UP en era tne tem ca 1ons-"fif roeo ors 2-St k M t Model No. Engine Displace Oil Injection Ignition (Hp) Type Year cu. in. (cc) System (j) System 175HPDI 6 76 LV 2-stroke 2001..3 158 (2596) Precision Blend TCI Micro 200 HPDI 6 76 LV 2-stroke 2(}()().()3 158 (2596) Precision Blend TCI Micro 200 EF/ 6 76 LV 2-stroke 191 (3130) Precision Blend COl Micro 225EFI 6 76 LV 2-stroke 1997..3 191 (3130) Precision BJend COl Micro 250 EFI 6 76 LV 2-stroke 1997..3 191 (3130) Precision Blend COl Micro 225HPDI 6 76 LV 2-stroke 2003 204 (3342) Precision Blend TCI Micro 250 HPDI 6 76 LV 2-stroke 2003 204 (3342) Precision Blend TCI Micro AH -Amp Hours CCA -Cold Cranking Amps Starting Fuel System System CCA (AH Reserve Electrlc HPDI 360 (100) 124 minutes Elecflic HPDI 360 (100) 124 minutes EJecflic EFI 512 (100) 182 minutes Electric EFI 512 (100) 182 minutes Elecflic EFI 512 (100) 182 minutes Electric HPDf 512 (100) 182 minutes Electric HPDI 512 (1 00) 182 minutes COl -Capacitor Discharge Ignition COl Micro -COl w/ Micro Computer Control VALVEMIN NOZZLE ----NEEDLE ..R.. MIN JET VALVE FLOAT ..--HINGE FLOATBOWL PIN Fig. 146 Exploded view of a typical non-fuel pump integrated carburetor used on 20ˇ48 hp 2-cylinder models 3ˇ38 FUEL SYSTEM .. Plug Screw Main Art Jet .. Pilot Air Jet Main Noz.zle Main Jet Screw (with Clip) Pilot Jet Screw Valve Seat (with 0-ring) /..Float (with needle valve) Pin Float Bowl (with O-Rin g) Drain screw (w/ 0-Ring) Fig. 147 Exploded view of a non-fuel pump integrated carburetor used on some larger 2-cylinder motors, including the 48 hp model 4. If necessary, loosen and remove the idle adjust (throttle stop) screw and spring. 5. Invert the carburetor body (with the float bowl facing upward), then loosen the float bowl retaining screws (usually 4). Remove the float bowl from the carburetor body, then remove and discard the old bowl gasket'packing (seal). 6. Push the float pin out to one side to separate the float from the carb. Lift gently upward to remove the float and needle valve from the carburetor body.• On some models there may be a molded arrow in the cover. This arrow is usually meant to show a preferred direction of movement for the pin sometimes it is the direction of installation and other times it is the for removal, so if equipped push gently in the direction of the arrow, and if the pin sticks, try the other direction, don't force it). 7. If equipped with a removable needle valve seat, loosen and remov& the seat retaining screw and clip, then remove the valve seat and 0-ring. Anytime you disassemble the carburetor it is a good idea to replace the needle valve and seat (if replaceable) to ensure proper float valve operation. 8. Remove the carburetor fuel metering components (main jet and nozzle, plug and pilot jet and, if equipped, the pilot air jet). Refer to the exploded views to help identify each component Be sure to keep them separated or tagged for installation or replacement purposes. FUEL SYSTEM 3-39 9. Clean and inspect all components as detailed in this section. Replace any damaged, worn or defective components. Discard all 0-rings or gaskets. To Assemble: 10. Install the fuel metering components (pilot air jet, the pilot jet and pilot jet plug, and then the main nozzle and main jet) to the carburetor body in the positions noted during removal. 11. If removed, install the needle valve seat and 0-ring then secure using the clip and retaining screw. 12. Connect the needle valve to the float, then lower the float and valve into position. Insert the hinge pin through the tloat and carburetor body using a pair of needle-nose pliers and gently tap into position. 13. With the carburetor still inverted and perfectly level, so the float is sitting gently on the needle valve (which is resting on the seat) measure the float height from the carburetor body-to-float bowl mating surface up to the top (actually the bottom, but it is on top now) of the float. Refer to the Carburetor Set-Up Specifications chart in this section for the allowable range. If necessary, gently bend the float hinge to achieve the proper measurement. ;f---;-, WARNING When measuring the float height DO NOT place any pressure downward on the needle valve or you could damage it (and/or you may make an incorrect adjustment). Fig. 148 The float bowl is normally secured by 4 screws and a gasket. •• Fig. 149 ..• it must be removed for access to the float assembly and most metering valves Fig. 150 The float is removed by freeing the hinge pin Fig. 151 The float needle valve and valve seat controls fuel flow from the pump Fig. 152 On some models the needle valve seat is easily replaced Fig. 153 Metering components (such as jets and nozzles) are installed into the carburetor body 3-40 FUEL SYSTEM 14. Double-check that the float and valve move smoothly without sticking or binding. 15. Install the float bow1 to the carburetor body using a NEW gaskeVpacking (seal), then secure using the retaining screws. If not already done, install the drain plug and 0-ring or gasket (as applicable). 16. 11 removed, install the idle adjust (throttle stop) screw and spring. 17. Install the pilot screw and spring. Slowly rotate the pilot screw into the carburetor body until it barely seats. From this position, back it out the appropriate number of turns (refer to the Carburetor Set-Up Specifications chart in this section). 18. If applicable (and if removed), install the carburetor top cover using a new gaskeVpacking, then secure using the retaining screws. 19. Install the carburetor and adjust for proper operation. CLEANING & INSPECTION + See Figures 90, 91, 145, 147, 154 and 155 .: :'. CAUTION Never dip rubber parts, plastic parts, diaphragms, or pump plungers in carburetor cleaner. These parts should be cleaned only in solvent, and then blown dry with compressed air. Check the float for deterioration. 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 in it. Inspect the tapered section of the float needle or pilot screw and replace any that have developed a groove. • As previously mentioned, most of the parts which should be replaced during a carburetor overhaul are included in overhaul kits available from your local marine dealer. Some of these kits will contain a matched fuel inlet needle and seat. When possible, this combination should be replaced each time the carburetor is disassembled as a precaution against leakage. Check the main jet, pilot jet, check valve and main nozzle for signs of dirt or contamination. If they cannot be cleaned, they should be replaced. Again, NEVER clean these components using a wire or any pointer instrument, you'll change the calibration. Always replace any and all worn parts. 3-Cylinder Powerheads + See Figures 156 and 157 Three carburetors are used on the 3-cylinder outboard powerheads. Complete, detailed and illustrated procedures for these carburetors follow. Removal procedures may vary slightly due to differences in linkage. The carburetorassembly used on 25/30 hp models contains an integral fuel pump on the middle carburetor. On these smaller models cold start enrichment is achieved using choke plates and linkage. The larger 28J-90 hp motors (698cc, 849cc and 1140cc models) utilize a remote mounted fuel pump assembly. On these larger motors, cold start enrichment may take the form of either choke plates/linkage or an enrichment valve. These differences will be noted whenever they make a substantial change in a procedure. When equipped with an electrothermal valve for cold start enrichment, it is mounted to the middle carburetor assembly and is used to provide additional fuel for cold start enrichment. When cold, the valve contains a piston which is retracted into the valve unblocking an additional fuel circuit in the carburetor(from the float bowl to the throttle bore). However, once the motor Place all metal parts in a screen-type tray and dip them in carburetor cleaner until they appear completely clean, then blow them dry with compressed air. Blow out all passages in the castings withcompressed air. Check all parts and passages to be sure they are not dogged or contain any deposits. Never use a piece of wire or any type of pointed instrument to clean drilled passages or calibrated holes in a carburetor. Move the throttle shaft back and forth to check for wear. If the shaft appears to betoo loose, replace the complete throttle body because individual replacement parts are not available. Inspect the main body, airhorn, and venturi cluster gasket surfaces for cracks and burrs which might cause a leak. Fig. 154 The mixing chamber of the carburetor used on most larger 2-cylinder motor must not be immersed in cleaning solution. The chamber contains plastic bushings around the throttle shaft. These bushings are pressed Into place and are not normally removed Fig. 155 Typical carburetor rebuild kit used on these motors ....., . is started the power from the stator/charge coil is applied to a heater element in the valve in order to gradually build heat in the valve. This process is timed to take about the same amount of time it should take a cold motor to warm to normal operating temperature. The temperature change causes the valve piston to extend, gradually cutting the enrichment circuit as the engine warms. Fig. 156 The three carburetors installed on the powerhead are identical (except for the fuel pump on the middle carb for 25/30 hp models) Fig. 157 Single carburetor disconnected from the series of carburetors and ready for service FUEL SYSTEM 3-41 REMOVAL & INSTALLATION 25/30 Hp (496cc) Models • See Rgures 158 thru 164 The middle carburetor on 25/30 hp motors is equipped with an integrated fuel pump assembly. The pump may be serviced, whether or not the carburetor is removed from the powerhead, by removing the bolts and carefully removing the cover, body and gasket/diaphragm assembly. The carburetors themselves are bolted to the powerhead using the air intake silencer housing/flame arrester assembly and 2 bolts per carburetor. As such, it is easier and safer to remove all 3 carburetors as an assembly, by keeping the bolts inserted through the flame arrester and the carburetor bodies, even alter each bolt is unthreaded from the powerhead itself. 1. Loosen and remove the four screws (usually 4} securing the air silencer cover to the air silencer housing/flame arrestor. Lilt the silencer coverand seal free of the flame arrestor. 2. Use a small screwdriver to carefully disconnect the powerhead choke and throttle linkage free of the carburetor linkage. You can leave the throttle and choke links connected from carburetor-to-carburetor and disconnect them only when/if you need to separate the carbs. 3. Tag and disconnect the fuel hoses from the carburetors. Most contain spring type clamps, loosen the clamps and slide them back up the hose past the raised portion of the nipple, then carefully separate the hose from the nipple. 4. Loosen, but DO NOT remove, all six bolts securing the flame arrestor/carburetor assembly to the intake manifold/reed block housing. As each bolt is freed from the powerhead, tape it into position on the flame arrester. Once the last bolt is removed from the powerhead the carburetor assembly should come free, carefully tm the flame arrester downward, keeping the carbs on top and in position on the retaining bolts. 5. Place the assembly on a suitable work bench. If it is necessary to separate the carbs, gently ease the flame arrestor from the three carburetors. Remove and discard the one piece gasket, which stretches from the top carburetor to the bottom carburetor. Remove the packing/seals !rom the powerhead side of each carburetor. 6. If necessary for further service, disconnect the throttle and choke linkage. Place each piece of linkage on the work bench in order as it is removed, as an aid during installation. Scribe a mark on the float bowl of each carburetor, 1, 2, 3 to ensure each is installed back in its original location. 7. Clean and inspect and/or overhaul the carburetor, as applicable. To Install: 8. Identify each carburetor by the mark scribed on the float bowl during removal. Check to be sure the small pieces of linkage were installed onto the correct carburetor. The throttle roller belongs on the carburetor with the fuel pump attached. Place the three carburetors In line on the work bench. Install the throttle and choke linkage. Place a new one piece gasket on the carburetor throats and align the flame arrestor to the carburetor assemblies. 9. Install a new seaVpacking to the powerhead side ol each carburetor. Align the carburetors to the flame arrester, then insert each of the mounting bolts through the flame arrestor (you can use tape to hold them from falling back out) and carburetors, then carefully lilt and position the carburetor/flame arrester assembly to the powerhead. Tighten all six bolts alternately and evenly until snug. 10. Reconnect the fuel hoses, as noted during removal. 11. Reconnect the powerhead choke/throttle linkage. 12. Install the air intake silencer cover and seal, then tighten the bolts securely. 13. Refer to the Timing and Synchronization adjustments in the Maintenance and Tune-Up section to make sure the Throttle Link and Idle Speed are properly adjusted. 3-42 FUEL SYSTEM Fig. 164 Remove the carburetors and flame arrester as an assembly Fig. 163 Carefully disconnect the powerhead linkage and fuel lines 28Jˇ90 Hp (698cc, 849cc & 1140cc) Models + See Figures 165 thru 174 On the 28J-90 hp motors (698cc, 849cc and 1140cc models), the 3 carburetors are normally secured to the powerhead by a common carburetor mounting plate. Like most of the other multi-carburetor Yamahas, bolts are inserted through a common mounting plate (usually a flame arrester on smaller models) and through the carburetors themselves to the powerhead. This makes removal a relatively simple matter that is usually performed by taking all 3 carburetors off at the same time, then separating them for service, if necessary. The one variation between the carburetors is that on some models the middle carburetor may contain an electrothermal enrichening valve for cold start operation. The balance of the motors use a choke plate/choke linkage for cold start enrichment. 1. Loosen and remove the screws (usually 4) securing the air silencer to the carburetor front plate. On Carburetors mounted on some units (usually the 28Jˇ50 hp motors) have two short upper screws and two long lower screws. However, most models have equal length screws. 2. With the bolts removed, carefully pull the air intake silencer from the carburetors. Keep track of the seals, there should be one for each carburetor. 3. Carefully disconnect the powerhead choke and/or throttle linkage from the carburetor assembly. There is no need to disconnect the links that connect the individual carburetors, as they are being removed as an assembly. 4. Squeeze the wire clamp with a pair of needle-nose pliers and gently pull off the fuel intake hose from the T fitting on the fuel manifold. If the open end of the hose shows signs of weeping fuel, plug the end of the hose with a suitable screw. Again, there is no need to disconnect the fuel manifold from the individual carburetors since they are being removed as an assembly. FUEL SYSTEM 3-43 Fig. 169 If equipped, disconnect the choke link. . . 5. If equipped with the PrecisionBiendŽ oil injection system, use a small ˇ screwdriver to carefully pry the oil injection link rod free of the plastic retainer on the bottom carburetor. 6. Loosen each of the carburetor assembly/mounting plate bolts, but do NOT remove them from the assembly (as they are the only things keeping the carburetors together once the bolts are free of the powerhead. If necessary, tape the bolts to the mounting plate to keep them from backing out. Once the last bolt is loosened and tree of the powerhead, carefully tilt the mounting plate downward and separate the entire carburetor assembly from the powerhead. 7. Remove and discard the one piece gasket used for all three carburetors. 8. If the carburetors must be separated for replacement or service, squeeze the ends of the wire clamps at the inlet fitting of each of the three carburetors and gently pull the fuel hoses from each fitting. • The T-fitting in the fuel line is located between the middle and bottom carburetors. 9. Disconnect the throttle and choke linkage. Place each piece of linkage on the work bench in order as it is removed, as an aid during installation. Scribe a mark on the float bowl of each carburetor, 1, 2, 3to ensure each is installed in its original location. 10. Clean and inspect and/or overhaul the carburetor, as applicable. To Install: 11. Identify each carburetor by the mark scribed on the fuel bowl during removal. Check to be sure the small pieces of linkage were installed on the correct carburetor. The throttle roller MUST be installed on the lower carburetor. Place all three carburetors in line on the work bench. Install the choke and throttle linkage on the port side of the carburetors. Fig. 170 .. . some models utilize a choke solenoid Fig. 168 If equipped, disconnect the oil pump link Fig. 171 loosen the 6 carburetor/front plate mounting bolts and remove the assembly ... 3ˇ44 FUEL SYSTEM Fig. 173 To separate the carburetors, Fig. 174 ... along with the choke and/or Fig.172 •••followed by the gasket disconnect the fuel manifold ••• throttle lfnkages 12. Turn the carburetors over on the workbench to rest on their port sides. Push each fuel hose onto its respective fuel inlet frtting on the starboard side. The T fitting is located between the middle and bottom carburetor. Secure each hose withthe wire clamp. 13. Place a new gasket in position over the reed block housing. The manufacturer recommends no sealant at this location. 14. Align the mounting plate with the carburetors, then insert of the botts through the mounting plate (you can use tape to hold them from falling back out) and carbs. Carefully lift and pos..ion the carburetor/mounting plate assembly to the powerhead. Tighten all six bolts aHernately and evenly until snug. 15. Reconnect the choke, oil pump and/or throttle linkage, as equipped. t6. Connect the fuel line from the fuel filter to the T fitting between the middle and bottom carburetors. 17. Install the air intake silencer and seal, then tighten the bolts securely. Some 28J.50hp motors have two short upper screws and two long lower screws, but most 3..ylinder models have screws of equal length. 18. Refer to the Timing and Synchronization adjustments in the Maintenance and Tune-Up section to make sure the Carburetor Link, Oil Pump Link and Idle Speed are all properly adjusted, as applicable. OVERHAUL + See Figures 175 thru 191 The following procedures pick up the work after the carburetors have been removed from the powerhead. The procedures for each of the three carburetors is identical, even for the 25/30 hp units with the fuel pump attached to the middle carburetor or larger units with an electrothermal valve and enrichening pump on the middle carb. However, additional steps are also provided which only apply to carbs with those components. Good shop practice dictates purchasing a carburetor repair kit and using new parts any time the carburetor is disassembled. Make an attempt to keep the work area organized and to cover parts after they have been deaned. This practice will prevent foreign matter from entering passageways or adhering to critical parts. 1. Remove the carburetor from the powerhead and drain all fuel from it using the float bowl drain screw. 2. Invert the carburetor body (with the float bowl facing upward), then loosen the float bowl retaining screws (usually 4). Remove the float bowl from the carburetor body (also known as a mixing chamber), then remove 3. With the float bowl removed you can access the float and needle valve assembly. Some models are equipped with a screw to lock the hinge pin in place, if so, loosen, but do not remove, the screw retaining the hinge pin in its groove. 4. Grasp the float and lift gently upward to remove the float and needle valve from the carburetor body. The needle valve. attached to the tang on the float will also slide out of the needle seat. 5. Pull the hinge pin from the float. Unhook the wire clip and needle valve from the tang on the float. 6. Remove the carburetor fuel metering components (plug and pilot jet, then main jet and nozzle}. Refer to the exploded views to help identify each component. Be sure to keep them separated or tagged for installation or replacement purposes. For most carburetors these components are removed as follows: a. Pry the small plastic plug from the center turret of the mixing chamber. b. Use a suitable size screwdriver and remove the pilot jet located under the plug. c. Remove the main jet from the center turret of the mixing chamber. d. Invert the mixing chamber and shake it, keeping a hand over the center turret. The main nozzle should fall free from the turret. If the nozzle refuses to fall out, gently reach in with a pick or similar instrument to raise the nozzle. 7. 1f equipped with a removable needle valve seat, loosen and remove the seat and 0-ring. Anytime you disassemble the carburetor it is a good idea to replaoe the needle valve and seat (ifreplaceable} to ensure proper float valve operation. • On most carburetors you'll need a thin walled socket to remove the needle valve seat. 8. Remove the screws securing the top cover to the top ol the carburetor body/mixing chamber. Lift off the cover. On some models the cover is sealed using a gasket or packing, if applicable, remove and discard the old seal. 9. Some models are equipped with a number (as many as 3) flat rubber plugs, two large and one small. Refer to the aooompanying exploding views to see what plugs are used on your model. Lift off the large rubber plug closest to the throttle plate. Lift off the remaining large rubber plug and the metal plate beneath it. The first rubber plug does not and should not have a metal plate under it. Lift off the small rubber plug and plate. and discard the old bowl gasket/seal. l--Throttle Stop Screw Fuel Pump Screw Float Bowl Fig. 175 E.xploded view of the ca.rburetor assembly -25130 hp models with carb Integrated fuel pump ˇ. ˇ,ˇ Fig. 176 Exploded view of the carburetor assembly -28J-90 hp motors (698cc, 849cc and 1140cc models) wtout an electrothermal enrichment valve 11 c mr (J) -< (J) --t m 3: (,.) I.. (J1 ... : :. 3-46 FUEL SYSTEM Clc;Illj._,"C<( 3:-Q)0 ...= CJ..tn ...Q)>0 Q)>.."'Q)tn Q)i5Q)Q) 10. Remove the pilot screw and spring from the carburetor. II is not necessary to countthe number ofturns in to a lightly seated position as a guide for installation, as the number of turns isspecified inthe Carburetor SetˇUp Specifications chart in this section. 11. Ifnecessary, loosen and removethe idle adjust(throttle stop) screw and spring. 12. For the middle carb on 25130hp motors with an integral fuel pump, it necessary remove the pump cover screws and disassemble the pump for inspection or component replacement. Remove the cover, body and diaphragm gaskets. 13. For the middle carb on 28J and larger motors with an electrothermal enrichment circuit, proceed as follows: a. Remove the retaining screw(s),then carefully lift the electrothermal valve from the float bowl. b. Loosen the enrichment pump cover screw, then remove the pump components (cover, diaphragmwith gaskets and check valve assembly. If necessary, loosen the screws and remove thevalves from the valve body (noting positioning for installation purposes). '....:.;; Fig. 179Loosen theboltsand remove the c 3: ClQ) cCJ ";rnocˇ..0 Fig.178 Exploded view of the enrichmentpump assemblyˇ 28Jˇ90 hp motors (698cc, 849cc and 1140cc models) with an electrothermal enrichment valve float bowl. •. Fig. 180 •••then remove the old gasket/seal Fig. 181 Remove the hinge pin..• FUEL SYSTEM 3-47 Fig. 182 . . . to free the float and needle valve assembly ˇ . .. . Fig. 185 This main jet was installed above... Fig. 186 .••this main nozzle Fig. 187 On most carbs, the needle valve seat is replaceable 14. Clean and inspect all components as detailed in this section. Replace any damaged, worn or defective components. Discard all 0-rings or gaskets. To Assemble: 15. For the middle cart on 28J and larger motors with an electrothermal enrichment circuit, proceed as follows: a. Assemble the enrichment pump using, at a minimum, new gaskets. Install the check valve assembly, diaphragm with gaskets and the pump cover, then tighten the bolts securely. b. The electrothermal valve is normally sealed using an Oˇring, make sure it is in good condition or, better yet, replace it to ensure there are no leaks. Install the valve and secure using the retaining screws. 16. For the middle carb on 25/30 hp motors with an integral fuel pump, install the pump body, cover and diaphragm/gaskets. Secure using the cover screws. Be careful not to damage the diaphragm/gaskets during assembly. 17. 11 removed, install the idle adjust (throttle stop) screw and spring. 18. Install the pilot screw and spring. Slowly rotate the pilot screw into the carburetor body until it barely seats. From this position, back it out the appropriate number of turns (refer to the Carburetor Set-Up Specifications chart in this section). 19. Some models are equipped with a number (as many as 3) flat rubber plugs in the top of the carburetor body. Proceed as applicable: a. Place the small metal plug in position over the smallest hole on top of the carburetor. Place the smallest rubber plug over the plate. b. Place the large metal plug in position over the large hole on top of the carburetor, nearest the fuel fitting, and then place one of the large rubber plugs over the plate. Place the remaining large rubber plug over the remaining hole. This plug is installed without a metal plate beneath it. 20. If applicable, install the top cover (using a new seal, if applicable) and When measuring the float height DO NOT place any pressure secure using the retaining screws. downward on the needle valve or you could damage it (and/or you may 21.11 removed, install a new Oˇring over the shaft of the needle valve make an incorrect adjustment). seat. Install and tighten the seat snugly. 22. Install the fuel metering components (main nozzle and main jet, then the pilot jet and pilot jet plug) to the carburetor body in the positions noted during removal. For most carburetors these components are installed in the following manner: a. Insert the main nozzle into the aft hole on the center turret. Position the series of holes in the nozzle to lace port and starboard when installed. b. Install the main jet over the main nozzle. Tighten the jet until it seats snugly. c. Install the pilot jet into the forward hole on the center turret. Tighten the jet until it seats snugly. d. Install the plug over the pilot jet. Push the plug in securely. A loose plug could wedge itself between the float and the float bowl. 23. Check to be sure the wire clip is securely in position around the needle valve. Slide the clip over the tang on the float, and check to see if the needle valve can be moved freely. 24. Slide the hinge pin through the hole in the float. 25. Lower the float assembly over the center turret, guiding the needle valve into the needle seat and positioning the end of the hinge pin to the carb body (under its retaining screw, when equipped). If applicable, tighten the screw securely. 26. With the carburetor still inverted and perfectly level, so the float is sitting gently on the needle valve (which is resting on the seat) measure the float height from the carburetor body-to-float bowl mating surface up to the top (actually the bottom, but it is on top now) of the float. Refer to the Carburetor SetˇUp Specifications chart in this section for the allowable range. If necessary, gently bend the float hinge to achieve the proper measurement. >' .:. WARNING 3-48 FUEL SYSTEM Fig.191 Remove the pilot screw for inspection 27. Double-check that the float and valve move smoothly without sticking or binding. 28. Install the float bowl to the carburetor body using a NEW gaskeVseal, then secure using the retaining screws. If not already done, install the drain plugand 0-ring or gasket (as applicable}. • Onsome models the float bowl and gasket areirregularlyshaped. For these models, be sure to match the one cutaway corner with the other. 29. Install the carburetor and adjust lor proper operation. Fig.190 .. . which may be Inspected/replacedas neces.sary CLEANING & INSPECTION .ODERATE • See Figures90, 91, 175 thru178 and192 thru196 'i,or-CAUTION Never dip rubber or plastic parts, in carburetor cleaner. These parts should be cleaned only In solvent, and then blown dry with compressed air. Placeall metal parts in a screen type tray and dip them in carburetor deaner until they appear completely clean, then blow them dry with compressed air. Blow outall passages in the castings with low-pressure compressed air. Checkall parts and passages to be sure they are not clogged or contain any deposits. Never use a piece of wire or any type of pointed instrument to clean drilled passages or calibrated holes in a carburetor. Move the throttle and, if applicable, choke shafts back and forth to check forwear.II the shalt appears to be too loose, replace the complete mixing chamber because individual replacement parts are not available. Inspectthe mixing chamber, and fuel bowl gasket surfaces for cracks and burrswhich might cause a leak. Check the float for deterioration. II any part of the float is damaged, the unit must be replaced. Inspect the tapered section of the float needle and pilot screw for wear or damage, Replace either if they have developed a groove or are no longer evenly tapered. Check the main jet, pilot jet and main nozzle for signs of dirt or contamination.II they cannot be deaned, they should be replaced. Again, NEVERcleanthese components using a wire or any pointer instrument, you'll change the calibration. If equipped with an integrated fuel pump or enrichment pump, check the diaphragmfor signs of deterioration or damage and replace. Obviously, there canbenopin holes in the diaphragm if you expect it to work properly. Of course,like all diaphragms, they weaken over time so if there is any doubt, just replace it to be save. Makesure the spring has not deformed or lost its strength. As previously mentioned. most of the parts which should be replaced duringa carburetor overhaul areincluded in an overhaul kit available from your local marine dealer. One of these kits will contain a matched fuel inlet needleand seat. This combination should be replaced each time the carburetor is disassembled as a precaution against leakage. If equipped with an electrothermal enrichment valve, check it as follows: FUEL SYSTEM 3-49 Fig. 192 Some of the parts included In the repair kit for most 3-cyllnder powerhead carburetors Fig. 193 A wire clip secures the needle valve to the float. If this wire should break or slip free of the float, the fuel supply will be cut off Fig. 194 Inspect the taper on the end ofthe pilot screw for ridges or signs of roughness. Good shop practice dictates a new pilot screw be installed each time the carburetor is overhauled Fig. 195 1f equipped with an electrothermal valve check resistance using a DVOM•.. Fig. 196 •..and check the valve height before and after connecting a 12 volt battery " Using an ohmmeter check the valve element resistance. Connect the ohmmeter across thetwo valve leads, it should read about 2.3-3.5 ohms resistance at an ambient temperature ol about 68°F (20"C). • Check the distance that the piston is protruding from the valve. Apply a 12 von power source to the 2 valve leads and leave it connected forseveral minutes, then recheck the valve piston height. If the valve is working properly the piston height should have changed (extended) as the internal valve element gradually heated. V4 & V6 Powerheads Yamaha V4 powerheads use two double-barreled carburetors and V6 powerheads use three double-barreled carburetors. Complete, detailed, illustrated, procedures to remove, service, and install the carburetors follow. Removal procedures may vary slightly due to differences in linkage. REMOVAL & INSTALLATION + See Figures 197 thru 208 • On V4 models, the enrichment valve Is normally mounted to the back side of the air intake silencer, so before pulling the silencer forward for access to the breather hose(s), it Is best to remove the Q.ring and disconnect the enrichment solenoid pull wire from the linkage. 1. Your first step isto gain access to the carburetors which are mostly obscured by the air intake silencer. Loosen and remove the silencer retaining bolts (usually 8 forV4 models and 12 for V4 models) then pull the silencer carefully away from the carbsjust enough to disconnect the breather hoses (intake manifold vent hose and, if equipped, oil tank airvent hose). • Pre-mix V4 models utilize a 2-piece air intake silencer cover and housing assembly. For these motors, remove the 8 bolts and cover (along with gasket), then remove the 8 bolts securing the housing and pull the housing forward for access to the Intake manifold vent hose. 2. On V4 models, if not donealready,remove the 0-ring and disconnect the pull wire from the carb linkage. Disconnect the solenoid valve wiring. II necessary, unbolt and remove the valve from the air intake silencer. 3. Wrth the hoses {and enrichment valve wiring for V4 motors) disconnected, remove the air intake silencer completely from the powerhead. Keep track of the silencer gasket (normally rubber). 4. Carefully disconnect the choke and/or throttle valve linkages on the port sideof the carburetor assembly. Disconnect the throttle link rod which attaches to the carburetorthrottle valves. 5. Carefullysnip the 2 (V4) or 3 (V6) plasticwire ties, then gently pull off the fuel supply hoses fromthe carburetors. 6. On the starboard side of the bottom carburetor, carefully pry the oil injection link from the linkage. 7. On V6 models, if not done already, pry off the little 0-ring which serves as a retainer for the choke solenoid pull wire. Take care not to lose this small part. Slip off the end of the pull wire from the carburetor linkage. The choke solenoid need not be removed on these models. 8.Identify each carburetor by inscribing or painting a 1, 2 and 3 {if applicable) on the mixing chamber cover to ensure each carburetor will be installed back into the same position from which it was removed. 9. Remove the mounting nuts, four on each carburetor, and then remove the carburetors as an assembly. Each carburetor has a separate gasket which may either come away with the carburetor, or remain on the intake manifold. Remove and discard these gaskets. Place the carburetor assembly on the workbench and remove each piece of linkage one at a time. Arrange the linkage on the workbench as it was installed on the carburetors, as an assist during assembling. To Install: 10. Identify each carburetor by the mark scribed on the mixing chamber during removal. Check to be sure the small pieces of linkage were installedonto the correct carburetor. On V4 models, the throttle roller is used on the lower carburetor. On V6 models, the throttle roller is used on thecenter carburetor. The choke and oil injection link retainers are located on the bottom carburetor. Place the carburetors in line on the work bench. Install the throttle and choke linkage. Place a new gasket onto the studs of the intake manifold. The manufacturer recommends NO sealant at this location. 3-50 FUEL SYSTEM Fuel Enrichment Valve cnnn••r.tt\r Cover vent hose Fig. 197 Exploded view of the carburetor mounting -pre-mix SOJ-140 Hp (1730cc) V4 Model Fuel Enrichment Valve Throttle Link Intake Intake Manifold Vent Hose Fig. 198 Exploded view of the carburetor mounting -oil-injected SOJ-140 Hp {1730cc) V4 Models Plastic Locking Oil Pump Link Rod ˇ:::ˇ ˇ::.:ˇ ˇ-.: . :. :ˇ' . Fuel Enrichment Valve Rod Intake Silencer Intake Manifold Air Vent Hose FUEL SYSTEM 3-51 Carburetor #1 Fig. 199 Exploded view of the carburetor mounting -105J-225 Hp (2596cc) V6 Models 11. Install each carburetor, then tighten the four mounting nuts for each ca.rburetor to atorque value of 5.8 ft. lbs. (8 Nm). 12. On V6 models, hook the choke solenoid pull wire loop into the linkage between the two choke rods. Slide the little D-ring over the linkage ball to retain the wire loop. The choke plunger adjustment is performed later. 13. On the starboard side of the bottom carburetor, snap the oil injection link rod into the linkage. If the length of this rod was accidentally changed adjust the length to specifications. 14. Slide the hoses over the inlet fittings and secure them using new plastic wire ties. 15. On the port side of the bottom carburetor, snap the choke link onto the carburetor choke arm. Check the action of thechoke linkage on the side of the carburetors by moving the choke lever in and out. 16. On V4 models, if the enrichment valve was removed from the back of the air intake silencer, install it now and secure using the retaining bolts. 17. Bring the inner silencer up to the installed carburetors. Reconnect the breather hose{s). On V4 motors, reconnect the enrichment valve wiring. Make sure the gasket(s) are in position, then seat the air intake silencer on the carburetors. Reconnect the enrichment solenoid valve pull wire and secure using the 0-ring. 18. Install and tighten the 8 or 12 bolts securing the air intake silencer to the carburetors. 19. On PreˇMix V4 models, install the air intake silencer cover and gasket, then secure using the 8 retaining bolts. 20. Referto the Timing and Synchronization adjustments in the Maintenance and Tune-Up section to makesure the carburetors and control linkage are properly adjusted. Fig.200 loosen the air intake silencer retaining bolts ..• Fig. 201 •.•then pull the housing forward to disconnect the breather hose(s) Fig. 202 Disconnect the choke andfor throttle linkage ••• 3-52 FUEL SYSTEM Fig. 206 V6 engines also use an enrichment Fig. 207 Mark each of the carburetors for Fig. 208 .•.then remove the nuts and (choke) pull wire identification . .. remove the carburetors OVERHAUL • See Figures 209 thru 219 The following procedures pick up the work after the carburetors have been removed from the powerhead, as outlined in the previous steps. The procedures for each of the two or three carburetors is identicaL Good shop practice dictates purchasing a carburetor repair kit and using new parts any time the carburetor is disassembled. Make an attempt to keep the work area organized and to cover parts after they have been cleaned. This practice will prevent foreign matter from entering passageways or adhering to critical parts. 1. Remove the carburetor unit from the powerhead, as detailed earlier in this section. 2. If not already done, remove the drain plugs and gaskets from the bottom sides of the float bowl and drain the fuelfrom the carburetor. 3. Use a small screwdriver to remove the pilot air jets. 4. Remove the Phillips screw securing the jet access cover to the carburetor. Remove the access cover. 5. Remove the 2 bypass screw plugs from the top of the carburetor mixing chamber. Remove and discard the two gaskets. 6. Remove both pilot screws and springs. It is not necessary to count the number of turns in to a lightly seated position, as a guide lor installation. The number of turns in is listed in the Carburetor SetˇUp Specifications chart in this section. 7. Invert the carburetor assembly, then remove the 4 securing screws and lift off the float bowl. Do not attempt to remove the gasket at this time. 8. Remove the two main jets, pilot jet plugs and pilot jets from the underneath and side of the float bowl. Remove and discard the gaskets and Oˇrings. 9. Slide the hinge pin outward to release the float. 10. Gently lift up the float. The needle valve, attached to the tang on the float, will also slide out of the needle seat. Unhook the wire loop and needle valve from the tang on the float. Remove the other float in a similar manner. 1t. Remove and discard the float bowl gasket from the mixing chamber. 12. On some models the needle seat is replaceable. For these, obtain the correct size thin walled socket and remove the needle seat. 13. Clean and inspect all components as detailed in this section. Replace any damaged, worn or defective components. Discard all (}rings or gaskets. To Assemble: 14. 11 applicable, install and tighten the needle seat snugly, using a thin walled socket. 15. Check to be sure the wire loop is securely in position around the needle valve. Slide the loop over the tang on the float, and then check to ensure the needle valve can be moved freely. Lower the float assembly into the mixing chamber guiding the needle valve into the needle seat. Install the other float in the same manner. 16. Slide the hinge pin through the mounting posts and float hinge, until the pin ends are flush with the mounting posts. 17. Hold the mixing chamber in the inverted position, (as it has been held during the past few steps). Measure the distance between the top of the float FUEL SYSTEM 3-53 Idle Adjust (throttle stop) screw and spring f Float Bowl 6 Nm (0.6 m • kgf, 4.3 ft • lb)..Gasket Bypass Screw Plug Carburetor Body (mixing chamber) 5 x 16 mm Pilot}Jet 5 Nm (0.5 m • kgf, 3.6 ft • lb) Pilot Jet Plug 3 Nm (0.3 m • kgf, 2.2 ft • lb) Fig. 209 Exploded view of the carburetor assembly -BOJ-140 Hp (1730cc) V4and 1 OSJ-225 Hp (2596cc) V6 Models Fig. 21 0 Remove the pilot air jets from the front of the carb Fig. 211 Remove the jet access cover and inspect the passages Fig. 212 Remove the bypass screw plugs and gaskets/oˇrings .•. 3-54 FUEL SYSTEM Fig. 216. . . then remove the float and needle valve Fig. 214 Loosen the bolts and remove the float bowl Fig. 217 Remove and discard the old float bowl gasket and the gasket. This distance should be in the float drop setting range of 0.61ˇ0.65 in. (15.5ˇ16.5mm) as indicated in the Carburetor Set-Up Specifications chart, found in this section. ..* WARNING . When measuring the float height DO NOT place any pressure downward on the needle valve or you could damage it (and/or you may make an incorrect adjustment). 18. If the distance is not as specified, remove the float and needle valve. Gently bend the tab on the float using a small screwdriver to correct the float level measurement. Repeat the float level measurement for the other float. 19. Double-check that the float and valve move smoothly without sticking or binding. 20. Install the main jets, float bowl drain screws wrth gaskets, pilots jets and pilot jet plugs with new gaskets. Install the jets into the float bowl and tighten them securely. Install new gaskets around the drain screws or plugs. Install into the float bowl and tighten them securely. 21. Place a new float bowl gasket in position over the mixing chamber. 22. Lower the float bowl over the floats. Take care not to disturb the float level adjustment. Install and tighten the attaching hardware. 23. Slide new springs over the pilot screws. Install the pilot screws into the carburetor. Tighten each screw until it JUST barely seats. From this position, back out the screw the number of turns specified in the float in the Carburetor Set-Up Specifications chart, found in this section. Fig. 215 Remove the hinge pin to free the float. .• • Take notice, as each model and sometimes year of manufacture could have a different pilot screw setting. Furthermore, on certain models, the port screw has a different setting from the starboard screw. Fig. 219 Measuring float height 24. Install new 0-rings/gaskets around the two bypass screw plugs, and then install them into the mixing chamber. 25. Install the pilot air jets and install the jet access cover (secure using the Philips screw). 26. Install the carburetors and adjust for proper operation. CLEANING & INSPECTION + See Figures 90, 91, 209 and 220 71"?;c CAUTION Never dip rubber or plastic parts in carburetor cleaner. These parts should be cleaned only in solvent, and then blown dry with compressed air. Actually, rubber and plastic parts should, whenever possible, be replaced. Place all metal. parts in a screen type tray and dip them in carburetor cleaner until they appear completely clean, then blow them dry with compressed air. Blow out all passages in the castings with low-pressure compressed air. Check all parts and passages (especially the jets and bleed valves) to be sure they are not clogged or contain any deposits. Never use a piece of wire or any type of pointed instrument to clean drilled passages or calibrated holes in a carburetor. Move the throttle and choke shafts back and forth to check for wear. If the shaft appears to be too loose, replace the complete mixing chamber because individual replacement parts are not available. Inspect the mixing chamber, and fuel bowl gasket surfaces for cracks and burrs which might cause a leak. ELECTRONIC FUEL INJECTION SYSTEMS Beginning wijh the 1997 model year Saltwater Series V76 some Yamaha engines are equipped with one of 3 types of electronic fuel injection. Although the original system was introduced in 1997 it continued even after the introduction of the 2 additional systems in 2000. The largest of the Yamahas may be equipped with eijher this manifold-injected EFI (OX66) system or a High Pressure Direct Injection (HPDI) system. In all cases, these systems improves low speed smoothness, reduce maintenance. improve durability, and increase fuel efficiency while lowering harmful engine emissions. In all cases an engine control computer known as the Engine or Electronic Control Module (ECM) is capable of adjusting fuel delivery and ignition timing over a wide range to match engine operation. Unlike carburetor-equipped engines, fuelˇinjected engines can automatically adjust for changes in altitude, air temperature, and barometric pressure. This precise control over engine operation results in crisp throttle response and maximum efficiency over a broad range of conditions. • For some reason the ECM is called the COl unit on EFI OX66 motors, however, since this unit does more than just control ignition, we think that is a little misleading and will refer to it as the ECM (the more commonly used term for fuel and ignition control units/models) throughout this repair However, knowing what Yamaha calls it might be handy when with a parts counterperson. Fuel Injection Basics. + See Figures 221, 222 and 223 Fuel injection is not a new invention. Even as early as the 1950s, various automobile manufacturers experimented with mechanical-type injection systems. There was even a vacuum tube equipped control unit offered for one system! This might have been the first "electronic fuel injection system." Early problems with fuel injection revolved around the control components. The electronics were not very smart or reliable. These systems have steadily improved since. Today's fuel injection technology, responding to the need for better economy and emission control, has become amazingly reliable and efficient. Computerized engine management, the brain of fuel injection, continues to get more reliable and more precise. Components needed for a basic computer-controlled system are as follows: FUEL SYSTEM 3ˇ55 Check the floats for deterioration. Check to be sure the needle valve loop has not been stretched. If any part of the float is damaged, the float must be replaced. Check the needle valve tip contacting surface and replace the needle valve if this surface has a groove worn in it. Inspect the tapered section of the pilot screws and replace a screw if it has developed a groove. Most of the parts which should be replaced during a carburetor overhaul are included in an overhaul kit available from your local marine dealer. Usually, one of these kits will contain a matched fuel inlet needle and seat. It is usually a good idea to replace this combination each time the carburetor is disassembled as a precaution against leakage. Pilot Air Pilot Air Jet Fig. 220 Check all jets, bleed valves and passages for signs of clogs or deposit • A computer-controlled engine manager, which is the Electronic Control Module (ECM), with a set of internal maps to follow (you know, if this, then do that type of information for the fuel and ignition systems). • A set of input devices to inform the ECM of engine performance parameters.• A set of output devices. Each device is controlled by the ECM. These devices modify fuel delivery and timing. Changes to fuel injection and timing are based on input information matched to the map programs. This list gets a little more complicated when you start to look at specific components. Some fuel injection systems may have twenty or more input devices. On many systems, output control can extend beyond fuel and timing. The Yamaha Fuel Injection System provides more than just the basic functions, but is still straight forward in its layout. There are somewhere between eight and twelve input devices and generally between six and ten output controls (depending upon the system, year and model). The accompanying diagrams show the typical input and output devices of the various Yamaha fuel injection systems. There are several fuel injection delivery technologies in wide use around the world and Yamaha has chosen to basically 2 forms of them for these motors. A br(ef discussion of the various types (even those not used by Yamaha) would be helpful in understanding the Yamaha systems. Throttle body injection is relatively inexpensive and was used widely in early automotive systems. This is usually a low pressure system running at 15 PSI or less. Often an engine with a single carburetor was selected for throttle body injection. The carburetor was recast to hold a single injector and the original manifold was retained. Throttle body injection is not as precise or efficient as port injection. Multi-port fuel injection is defined as an engine that uses one or more electrically activated solenoid injectors (or physically actuated injectors in the case of General Motors Central Multi-Port Injection used in some 1990's era vehicles) for each cylinder. Multi-port injection generally operates at higher pressures than throttle body systems. The Yamaha EFI systems operate with a system pressure of somewhere in the 30ˇ40 psi (207ˇ278 kPa) range depending upon the year and model. The Yamaha EFI system uses a type of port injection where the fueVoil mixture is injected into the air intake track behind the throttle bodies and before the reed valves. Another type of Multi-port fuel injection used predominantly on 2-stroke marine engines (but also found on automotive and marine diesels) is Direct 3-56 FUEL SYSTEM Injection, which is called so because fuel is introduced from the injector DIRECTLY into the combustion chamber. The Yamaha HPDI motors are an example of this type of fuel injection system. Whereas for many years mo..t diesel engines achieved this using fuel line pressure wh1ch over..omes spnng pressure in the injector, more and more modern systems ..re us1n.. electronically actuated injectors. This type of system reqUires a higher pressure fuel charge to operate properly, and Yamaha HPDI systems operate on fuel pressures up to 1000 psi (6895 kPa) on some d1rect 1n!ect10n motors. No matter whether the fuel is injected to the manifolds, beh1nd or directly into the combustion chamber, the real advantage of a system is the precise cont..ol ..!forded the ..CM b.. ..he use of h1gh response electronic components. Th1s g1ves electromc fuel inJectors are great advantage over mechanical injectors when it comes to emissions and operating efficiency. Port injectors can be triggered two ways. One system uses simultaneous injection. All injectors are triggered at once. The fuel "hangs around" until the pressure drop in the cylinder pulls the fuel into the combustion chamber. This type of system looses some of the advantage that is possible with an electronic fuel injector. The secon.. type is mor.. prease and follows the firing order or SEQUENCE of the engme. Each cylinder g..ts a squirt of fuel precisely when needed. If you haven't guesse... th_1s second type of fuel injection is known as Sequential Fuel InJection. ELECTRIC FUEL PUMP IGNmON CONTROL KNOCK SENSOR THROTTLE SENSOR PRESSURE REGULATOR VAPOR SEPARATOR TANK OIL PUMP Yamaha EFI OX66 Injection + See Figures 221 and 222 The Yamaha EFI OX66 system is a tuned port, seque..tial method of fuel injection. The injectors are located between the throttle a1r valves and the reed valves. The ECM controls fuel and ignition timing in two stages. In stage one, the ECM (remember, Yamaha calls it the CDI unit on _these models) controls ignition timing and fuel injection volume accord1nQ_to information gathered about engine speed from the Cran..haft Pos111on Sensor (CPS) and throttle opening from the T..rottle Pos1t1o.. Sen..or In stage two, the ECM fine tunes the fuel m1xture accord1n9 to from several other sensors, especially the Oxygen sensor. Th1s second stage is sometimes referred to as closed-loop mode and is very similar to the method of fuel injection management found in neary all modern automobiles. Closed-loop mode means that the oxygen sensor information is used to control enrichment. In an open loop condition, one or more sensors (the oxygen sensor is usually the c..ical inpu!) is missing or out of range. Openˇ loop operation controls the eng1ne by a f1xed ..ap or pre-programmed information in the ECM. In closed-loop operation, the ECM uses Oxygen sensor feedback to continuously monitor how good a job the ECM is doing in FUEL CONTROL RPM SENSOR (PULSER) FUEL ALTER BAlTERY 02SENSOR .. FUEL FUEL TANK OIL TANK Fig. 221 Yamaha Electronic Fuel Injection (EFI OX66) operational schematic (note the 02 sensor which makes this system unique) managing combustion, then uses the information to better ..anage air/fuel mixtures and ignition timing. The amount of Oxygen found 1n exhaust gases therefore becomes the piece of the puzzle that closes the "loop• of fuel_ .management, the results of engine management are use.. to make dec1s1ons on future engine management which produces results whiCh are used for feedback and you have a circular pattern. . .An additional feature of the Yamaha system is return-to-port capability or limp mode. If there is a major sensor failure that prevents the ECM from processing, the engine is ..n on a minimum pe..ormance map. The only input that will shut the eng1ne down completely IS battery voltage. If the battery is disconnected or the battery voltage falls below 9 volts, the fuel pump quits pumping so the engine stops. Major components of this system include the ECM and Sensors along with the low-and high-pressure fuel delivery circuits. The electronic control sensors include: • Throttle Pos..ion Sensor (TPS) • Intake Air Temperature (IAT) Sensor • Atmospheric Pressure Sensor (APS) • Knock Sensor (3.1L engine only) • Oxygen Sensor • Water Temperature Sensor (WTS) • Crankshaft Position Sensor (CPS) • Pulsar Coil The low-pressure fuel circuit is almost identical to the fuel delivery circuit found on carbureted motors. A fuel line with primer bulb is used to connect the boat mounted or portable fuel tank to one or more pov.:erhead mounted diaphragm-displacement fuel pump(s). The low-pressure e.rcu1t IS used to deliver fuel from the fuel tank to a powerhead mounted vapor separator tank FUEL SYSTEM 3ˇ57 which contains a submerged high-pressure electric fuel pump. The vapor tank also receives 2-stroke engine oil from and oil pump. The _ high-press..re pump then draws fuel and oil from the vapor tank ..nd forces it through h1ghˇ pressure fuel lines to the fuel injectors for each cylinder. Yamaha High Pressure Direct Injection (HPDI) • See Figure 223 The Yamaha HPDI system is, as the name suggests, a direct to the combustion chamber injection system which operates under extreme pressure. Because the fueVoil mixture is s..rayed directly into the chambers timing is critical, meaning_there IS no re..l way to.. a dJrect system to be anything BUT sequential. Fuel mapp1ng deas1ons are based upon a combination of factors including . . •engine speed from the Crankshaft Pos111o.. Senso.. (CPS), throttle from the Throttle Position Sensor (TPS) and 1ntake a..r from the Intake Temperature (IAT) sensor and Atmospheric Pre..sure S..nsor (AP..). In this way the ECM keeps track of just how much a1r IS entenng the eng1ne (between the TPS and the temperature/pressure of the air) and can adjust air/fuel mixture ratios to suit operating conditions. A lack of Oxygen ..ensor makes this form of injection open-loop only (meamng the ECM rece1ves no feedback on the combustion process). .Like most fuel injection systems, the Yama..a HPDI system Incorporates a return-to-port capability or limp mode. If there IS a_ maJOr sensor ..a1lu..e that prevents the ECM from processing on.. or more s1gnals, the. eng me _1s run on a minimum performance map. In most mstances the ECM w1ll ..ubstitute a fixed value for the missing sensor signal. The only 1nput that will shut the -f AIR INDUCTION SYSTEM ELECTRONIC FUEL INJECTION FUEL SYSTEM ELECTRONIC CONTROL SYSTEM Spa•k pl"g SYSTEM • AIR INDUCTION SYSTEM 1. TH1l01TLE POSITION SENSOR 2. AIU TEMPERATURE SENSOR 3. Alit PRESSURE SllNSOR 4. OXYGEN SENSOR 5. KNOCK SENSOR 6. WATER TEMrERATURESENSOR 7. CRANK POSITION SENSOR 8. PULSER COIL Remote oil tank Fig. 222 Yamaha Electronic Fuel Injection (EFI OX66) components (note the 02 sensor which makes this system unique) FUEL SYSTEM ... Gasoline 3-58 FUEL SYSTEM Trailer switch @ High-pressure fuel pump @ High-pressure fuel pump resistor -pressure fuel pump Q) Thrott!4 position sensor @ High-pressure fuel pump connectors @ Higt>-pressure fuel pump resistor couplers (2Pl Fig. 281 2.6L EFI OX66 • Port side of motor (j) Oil level sensor (!) Fuel injector coupler (6Pl (j) Throttle position sensor coupler (3P) Ž Oil level sensor coupler (6P) Ž Purser coil coupler (6Pl Ž Trailer switch coupler (3P) Rectifier/regulator Fig.293 3.1l EFI OX66 ˇ Junction box assembly [ID@ Complete assembly liD Sub-assembly.. To power trim and tilt motor [Q] To wire harness 00 To battery 1!1 To starter motor (Q] To fuel injector unit IEl To COl unit ffi To lighting coil 11! To oxygen density sensor (j) Ignition coils Ž Ignition coil connectors Ž Thermo switch connectors CRANKCASE PRESSURE Fig. 303 A fuel pump is a basic mechanical device that pulls fuel from the tank. It utilizes crankcase positive and negative pressures to pump fuel FUEL SYSTEM 3-101 the pump and NOT with fuel tank, lines or filter. A plugged tank vent could create vacuum in the tank that will overpower the pump's ability to create vacuum and draw fuel through the lines. An obstructed line or fuel filter could also keep fuel from reaching the pump. Any of these conditions could partially restrict fuel flow, allowing the pump to deliver fuel, but at a lower pressure/rate. A pump delivery or pressure test under these circumstances would give a low reading that might be mistaken for a faulty pump. Before testing the fuel pump, refer to the testing procedures found under Fuel Unes and FtHing to ensure there are no problems with the tank, lines or filter. Aquick check of fuel pump operation is to gently squeeze the primer bulb with the motor running. If a seemingly rough or lean running condition (especially at speed) goes away when the bulb is squeezed, the fuel pump is suspect. If inadequate fuel delivery is suspected and no problems are found with the tank, lines or filters, a conduct a quick-check to see how the pump affects performance. Use the primer bulb to supplement fuel pump. This is done by operating the motor under load and otherwise under normal operating conditions to recreate the problem. Once the motor begins to hesitate, stumble or stall, pump the primer bulb quickly and repeatedly while listening tor motor response. Pumping the bulb by hand like this will force fuel through the lines to the vapor separator tank, regardless of the fuel pump's ability to draw and deliver fuel. If the engine performance problem goes away while pumping the bulb, and retums when you stop, there is a good chance you've isolated the low pressure fuel pump as the culprit. Depending upon the model you may be able to perform a pressure or vacuum check (Yamaha tends to recommend the later) or you'll have to disassemble the pump to physically inspect the check valves and diaphragms (your only option on carburetor integrated pumps, but it's not that difficult and can be done on ALL pumps). .r<-;!. WARNING Never run a motor without cooling water. Use a test tank, a flushJtest device or launch the craft. Also, never run a motor at speed without load, so for tests running over idle speed, make sure the motor is either in a test tank with a test wheel or on a launched craft with the normal propeller installed. Vacuum Checking the Delivery System + See Figure 304 Fuel system vacuum testing is an excellent way to pinpoint air leaks, restricted fuel lines and fittings or other fuel supply related performance problems. When a fuel starvation problem is suspected such as engine hesitation or engine stopping, perform the following fuel system test to see if you should check the fuel tank, filter(s} and lines or check the pump itself: 1. Connect the piece of clear fuel hose to a side barb of a "T" fiHing. 2. Connect one end of a long piece of fuel hose to the vacuum gauge and the other end to the center barb of the "T" fiHing. Fig. 304 Connecting a vacuum gauge inline in preparation for isolating fuel system problems • Use a long enough piece of fuel hose so the vacuum gauge may be read at the helm. 3. Remove the existing fuel hose from the fuel tank side of the fuel pump (that usually means between the fuel filter and the fuel pump), and connect the remaining barb of the "T"fitting to the fuel hose. 4. Connect the short piece of clear fuel hose to the fuel check valve leading from the fuel filter. If a check valve does not exist, connect the clear fuel hose directly to the fuel filter. 5. Check the vacuum gauge reading after running the engine long enough to stabilize at full power. • The vacuum is to not exceed 4.5 in. Hg (15.2 kPa) for up to 200 hp engines. The vacuum is to not exceed 6.0 in. Hg (20.3 kPa) for engines greater than 200 hp. On the bright side, if the vacuum DOES exceed this figures, the problem is more than likely NOT the pump! 6. An anti-siphon valve (required if the fuel system drops below the top of the fuel tank) will cause a 1.5 to 2.5 in. Hg (8.4 kPa) increase in vacuum. 7. 11 high vacuum is noted, move the T-fiHing to the fuel filter inlet and retest. 8. Continue to the fuel filter inlet and along the remaining fuel system until a large drop/change in vacuum locates the problem. 9. Agood clean water separator fuel filter will increase vacuum about 0.5 in. Hg (1.7 kPa). 10. Small internal passages inside a fuel selector valve, fuel tank pickup, or fuel line fiHings may cause excessive fuel restriction and high vacuum. 11. Unstable and slowly rising vacuum readings, especially with a full tank of fuel. usually indicates a restricted vent line. • Bubbles in the clear fuel line section indicate an air leak, making for an inaccurate vacuum test. Check all fittings for tightened clamps and a tight fuel filter. • Vacuum gauges are not calibrated and some may read as much asˇ2 in. Hg (6.8 kPa) lower than the actual vacuum. It is recommended to perform a fuel system test while no problems exist to determine vacuum gauge accuracy. Checking Pump Pressure A basic low-pressure fuel pump pressure check is included n the Fuel System Checks found under the Maintenance and Tune-Up section of this guide. Unfortunately, Yamaha does not publish pump pressure specifications for their 2-stroke motors, so the information should be used to decide whether or not further diagnosis seems necessary on those motors. You can check fuel pump delivery by measuring the amount of fuel that Is expelled from a disconnected fuel pump outlet hose while the motor runs at speed for one minute. ln order to safely conduct this test the motor must either be in a test tank or on a launched craft as engine speed should be maintained toward the high end of mid-range (about 3000 rpm, but check the Engine Specifications charts for exact requirements). Before starting the test you'll need to run the engine and make sure the carburetor float bowl(s) are full (since they won't continue to receive fuel once the test is started). Carefully disconnect the fuel pump outlet line from the carburetor(s) and direct it into an approved container. Start and run the engine for one minute, then shut down the powerhead and measure the amount of fuel collected using a graduated cylinder or beaker. Fuel Pump Diaphragm and Check Valve Testing • See Figures 305 and 306 For non-carburetor integrated fuel pumps you can use a simple handˇheld vacuum/pressure pump and gauge to perform basic tests of the fuel pump diaphragm and check valve conditions. Sometimes we have a hard time geHing a grip on why a manufacturer chooses to do some of the things they do. When it comes to Yamaha service information, the format of what is or what is not available for a motor 3-102 FUEL SYSTEM sometimes make no sense. In this case we bring this up because sometimes it might just be who at Yamaha wrote the given service publication or update, because they specifically give this vacuum/pressure check for all V6 and V6, but only a few of the inline motors (such as the 46 hp twin), even when there appear to be no differences in the designs of the pumps themselves. For this reason, we feel that this test is applicable to all Yamaha, noncarburetor integrated diaphragm-displacement fuel pumps. However, if the motor on which you are working is not listed, we recommend that you DO NOT condemn it based on these test results until after you've also disassembled it (the only way that Yamaha recommends testing it in that case). However, conversely, if the pump DOES pass this test, we feel it is VERY likely that the pump is not your problem. Attach a hand-held vacuum/pressure pump (like the Mity VacŽ) to the fuel pump inlet fitting (the fitting to which the filter/tank line connects). Using the pump apply 7 psi (50kPa) of pressure while manually restricting the outlet fitting (or fittings, there are 2 on some pumps) using your finger. If the diaphragm is in good condition it will hold the pressure for at least 1 0 seconds. Next, switch to the vacuum fitting on the pump and draw 4.3 psi (30 kPa) of negative pressure (vacuum) on the fuel pump inlet fitting. This checks if the one-way check valve in the pump remains closed. It should hold vacuum for at least 1 0 seconds. ressure Vacuum Fig. 305 Vacuum/pressure checking a typical Yamaha fuel pump Fig. 306 Some pumps are equipped with 2 outlets Now, move the pressure pump to the fuel pump outlet fitting. This time cover the inlet fitting (and other outlet fitting, if applicable) with your finger and apply the same amount of pressure. Again, the pressure must hold for at least 10 seconds. • If pressure does not hold, verify that it is not leaking past your finger (on the opposite or fittings) when applicable or from a pump/hose test connection. leakage Is occurring in the diaphragm, the fuel pump should be overhauled. Visually Inspecting the Pump Components + See Figures 307, 308 and 309 The only way that Yamaha recommends to inspect MOST of their diaphragm-displacement fuel pumps (including all carburetor-integrated pumps) is through disassembly and visual inspection. Remove and/or disassemble the pump according to the procedures found either in this section (for non-integrated pumps) or under Carburetor Service (specifically Overhaul, for carburetor-integrated models). Wash all metal parts thoroughly in solvent, and then blow them dry with compressed air. Use care when using compressed air on the check valves. Do not hold the nozzle too close because the check valve can be damaged from an excessive blast of air. Inspect each part for wear and damage. Visually check the pump body/cover assembly for signs of cracks or other damage. Verify that the valve seats provide a flat contact area for the valve. Tighten all check valve connections firmly as they are replaced. Check the diaphragms for pin holes by holding it up to the light. If pin holes are detected or if the diaphragm is not pliable, it MUST be replaced. • If you've come this far and are uncertain about pump condition, replace the diaphragms and check valves, you've already got to replace any gaskets or Oˇrings which were removed. Once the pump is rebuilt, you can remove it from your list of potential worries for quite some time. REMOVAL & INSTALLATION + See Figure 310 • Disassembly and assembly should be perfonned on a clean work surface. Make every effort to prevent foreign material from entering the fuel pump or adhering to the diaphragms. These procedures cover removal, installation and overhaul of the powerhead mounted diaphragm-displacement fuel pump found on most Yamaha motors. For models with carburetor integrated pumps, please refer to the appropriate carburetor overhaul procedure found earlier in the Carburetor Service section. 1. For safety, disconnect the negative battery cable, if equipped, and/or remove and ground the spark plug lead(s). Also for safety, on motors with portable tanks, disengage the quick-connect fitting from the motor. • These actions will help prevent the possibility of sparks that could potentially ignite fuel vapors, help prevent accidental starting of the motor while you are working on it, and lastly, help prevent raw fuel from spraying through an open fitting (should someone squeeze or step on the primer bulb). 2. Tag and disconnect the fuel lines from the pump itself. On most motors there is a spring-type clamp securing the fuel inlet and outlet lines, but some use plastic wires which must be carefully cut for removal ijust make sure you don't nick and damage the fuel line itself). The inlet and outlet line fittings on the pump are normally labeled to show proper fuel flow connection. • These clamps are easily disconnected by squeezing the clamp ears and slid upward along the fuel hose, until they are past the raised portion of the raised portion on the pump connection. FUEL SYSTEM 3ˇ103 Fig. 307 Typical carburetor-integrated fuel pump Fig. 310 Fuel pump removal or installation on a typical powerhead Fig. 308 Typical crankcase mounted fuel pump 3. Remove the bolts (normally 2) securing the pump itself to the crankcase. Don't confuse these bolts (normally found on either side of the fuel inlet fitting end of the pump) with the cover screws (there are usually 3 pump cover screws which are used to disassemble the pump itseiQ. 4. Carefully remove the pump assembly from the powerhead, then remove and discard the crankcase gasket. 5. Installation is essentially the reverse of this removal. However, make sure the crankcase passage is clean and free of dirt or debris. Also, be sure to use a new gasket. Always be sure to properly pressurize the fuel system and check for leaks before attempting to start and run the motor. It is also a good idea to run the motor with the cover removed and observe the fuel lines and fittings which were disconnected, JUST TO MAKE SURE there are no leaks the first time the outboard is started after a fuel pump/system repair. OVERHUAL + See Figures 311, 312 and 313 1. Remove the pump and move it to a suitable clean work surface. 2. Remove the pump cover screws (these are usually 3 Philips head screws) that secure the pump cover and body together. Take care not to let the spring fly out or to lose the cup. 3. Separate the back cover from the pump body. If the gasket and diaphragm are to be used again, take great care in peeling them away from the surface of the cover. Remove the spring and cup. Separate the parts and keep them in order as an assist in assembling. 4. Remove the front cover from the pump body. If the diaphragm and gasket are to be used again, take great care in peeling them away from the .surface of the cover. Separate the parts and keep them in order as an assist in assembling. 5. Remove the check valves and take time to note how each valve faces, because it MUST be installed in exactly the same manner, or the pump will not function. To Assemble: • Proper operation of the fuel pump is essential for maximum powerhead performance. Therefore, always use new gaskets. : ˇˇ WARNING Never use any type of sealer on fuel pump gaskets. 3-104 FUEL SYSTEM 6. Place the check valves on the appropriate sides of the pump body (in the positions noted during removal) with the fold in the valve facing up. Take care not to damage the very fragile and flat surface of the valve. Secure each check valve in place with a Phillips head screw. Tighten the screw securely. 7. Place the spring, the cup (on top of the spring), the diaphragm, the gasket, and finally the inner cover on the pump body. Hold these parts together and turn the pump over. 8. Install the gasket and then the diaphragm onto the pump body. Install the front cover. 9. Check to be sure the holes for the screws are all aligned through the cover, diaphragms, and gaskets. If the diaphragms are not properly aligned, a tear would surely develop when the screws are installed. Install the three Phillips head screws through the various parts and tighten the screws securely. 10. Properly install the pump to the powerhead and pressurize the system to make sure there are no fuel leaks. Fig. 311 Three screws usually secure the Fig. 312 Carefully pull back the pump covers Fig. 313 Note the check valve positioning pump components to expose the diaphragms before removal REED VALVES ˇ Reed Valve Block + See Figure 314 On 2-stroke motors the combustible air/fuel oil mixture is drawn into the crankcase from the carburetors through reed valves. It is the job of the reed valve to open in response crankcase vacuum (allowing the air/fuel mixture to be drawn from the carburetor, through the intake manifold and into the motor) and then to close again during crankcase pressure (allowing that same mixture to be forced through the ports into the combustion chamber). The reed valves essentially take the place of the more complicated valve train used on 4-stroke motors (which is necessitated by the basic differences in engine operation). 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 was installed incorrectly or the stop has become distorted. If the reed is broken, the loose piece must be located and removed, before the powerhead 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. An excellent check for a broken reed on an operating powerhead 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 onto the card. A broken reed will cause the powerhead to operate roughly and pop back through the carburetor. 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 break in a very short time. The reed block is located on the engine crankcase, under the carburetors and intake manifold. Removal and installation of the block is part of Powerhead overhaul and is covered in the Powerhead section. Obviously, a complete disassembly of the powerhead itself is not necessary simply to access the reed valves, so if that is the only required service, just follow the appropriate steps of the overhaul procedure. Fig. 314 The reed block on most powerheads (including the V4 or V6) may be serviced without disassembling the powerhead FUEL SYSTEM 3-105 Carburetor Set-Up Specifications -2-Stroke Motors SPECIFICATIONS Pilot Screw Float Valve Seat Model No. Engine Displace Initial Low Height/Drop Setting Size (Hp) ofCyl Type Year cu. in. (cc) Speed Setting ln. (mm) ln. (mm) 2 1 IL 2-stroke 1997-02 2.6 {43) -0.66-0.70 {16.8-17.8) 0.055 (1.4) IL 2-stroke 1997-02 3.0 (50) -0.66-0.70 (16.8-17.8) 0.055 (1.4) 3 1 IL 2-stroke 1997-02 4.3 (70) 1-1112 0.47-0.63 (12-16) 0.055 (1.4) 4 1 1997-99 5.0 (83) 1112-2 0.85-0.89 (21.05-22.05) 0.05 (1.2) 4 1 CL 1997-02 6.3 (103) 1114-1314 0.85-0.89 (21.05-22.05) 0.05 (1.2) 5 1 CL 1997-02 6.3 (103) 1114-1314 0.85-0.89 (21.05-22.05) 0.05 (1.2) 6 2 CL 1997-00 10 (165) 718-12/8 0.47-0.63 (12-16) 0.05 (1.2) 8 2 CL 1997-03 10 (165) 718-12/8 0.47-0.63 (12-16) 0.05 (1.2) 9.9 2 IL 2-stroke 15 (246) 1 1/4 -1 3/4 0.49-0.61 (12.5-15.5) 0.05 {1.2) 15 2 IL 2-stroke 1997-03 15 (246) 1 1/4 -1 3/4 0.49-0.61 (12.5-15.5) 0.05 (1.2) 20 2 IL 2-stroke 1997 24 (395) 1 3/4 -2 1/4 0.55-0.59 (14-15) - 25 2 IL 2-stroke 1997-03 24 (395) 1 1/4-2 3/4 0.55-0.59 (14-15) - 20 2 IL 2-stroke 1997-98 26 (430) 1 1/8-1 5/8 0.69-0.73 (17.5-18.5) 0.055 (1.4) 25 2 IL 2-stroke 1997-98 26 (430) 1 1/4-1 3/4 0.69-0.73 (17.5-18.5) 0.055 (1.4) 25 2 IL 2-stroke 1997 30 (496) 1 -1 1/2 0.571 (14.5) 0.05 (1.2) 30 2 IL 2-stroke 1997 30 (496) 1 -1 3/4 0.571 (14.5) 0.05 (1.2) 40 2 IL 2-stroke 1997 36 (592) 1 1/2 -2 0.65-0.89 (16.5-22.5) 0.055 (1.4) 2 IL 2-stroke 1997-00 46 (760) 1 1/8 -1 5/8 0.71-0.79 (18.0-20.0) 0.06 (1 .6) 25 3 IL 2-stroke 1997-02 30 (496) 1/2-1 0.61-0.65 (15.5-16.5) 0.04 (1.1) 30 3 IL 2-stroke 1997-02 30 (496) G) 0.57-0.61 (14.5-15.5) 0.04 (1.1) 28J 3 IL 2-stroke 1997-01 43 (698) 1 1/4 -1 3/4 0.55-0.63 (14-16) 0.05 (1.2) 35J 3 IL 2-stroke 1997-01 43 (698) 1 3/8 -1 7/8 0.55-0.63 (14-16) 0.05 (1.2) 40 3 IL 2-stroke 1997-03 43 (698) 1 1/4 -1 3/4 0.55-0.63 (14-16) 0.05 (1.2) 3 IL 2-stroke 1997-03 43 (698) 1 3/8 -1 7/8 0.55-0.63 (14-16) 0.05 (1.2) 3 IL 2-stroke 1997-03 52 (849) 1 1/8 -1 5/8 0.55-0.63 (14-16) 0.05 {1.2) 60 3 IL 2-stroke @ 52 (849) 1 1/4 -1 3/4 0.51-0.59 (13-15) 0.063 (1.6) 3 IL 2-stroke Ž 52 (849) 1 1/8-1 5/8 0.47-0.63 (12-16) 0.055 (1.4) 70 3 IL 2-stroke 52 (849) 1 -1 1/2 0.51-0.59 (13-15) 0.055 (1 .4) 65J 3 IL 2-stroke 1997-01 70(1 140) 1 -1 1/2 0.65-0.89 (1 9.2-19.8) 0.06 (1.6) 75 3 IL 2-stroke Ž 70 (1 140) 1 1/8 -1 5/8 0.51-0.59 (13-15) (j) 0.06 (1.6) 3 IL 2-stroke Ž 70 (1140) 1 -1 1/2 Ž 0.65-0.89 (16.5-22.5) 0.06 (1.6) 80 3 IL 2-stroke 1997-00 70 (1140) 1 1/8 -1 5/8 0.51 -0.59 (13-15) Ž 0.06 (1.6) 85 3 IL 2-stroke 1997-00 70 (1 140) 718-1 3/8 0.65-0.89 (1 6.5-22.5) 0.06 (1.6) 3 IL 2-stroke 1997-03 70 (1 140) 1 -1 1/2 0.51-0.59 (13-15) 0.06 {1 .6) 80J 4 90 LV 2-st 1997-98 106 {1730) 3/8 -718 0.61-0.65 (1 5.5-16.5) 0.05 (1.2) 4 90 LV 2-st 1999-01 106 (1730) 1 -1 1/2 0.61-0.65 (1 5.5-16.5) 0.05 (1.2) 100 4 90 LV 2-st 1997-02 106 {1730) 1 -1 1/2 0.61-0.65 (15.5-16.5) 0.05 (1.2) 115 4 90 LV 2-st 1997-98 106 {1 730) 3/8 -7/8 0.61-0.65 (15.5-16.5) 0.05 {1 .2) 4 90 LV 2-st 1999-03 106 (1 730) 1 -1 1/2 0.61-0.65 (15.5-16.5) 0.05 (1.2) 130 4 90 LV 2-st 1997-03 106 (1 730) 5/8 -1 1/8 0.61-0.65 (15.5-16.5) 0.05 (1.2) 140 4 90 LV 2-st 1997-02 106 (1 730) 5/8 -1 1/8 0.61-0.65 (15.5-16.5) 0.05 (1.2) 105J 6 90 LV 2-st 1997-00 158 (2596) 3/4 -1 1/4 0.61-0.65 (15.5-16.5) 0.05 (1.2) 3-106 FUEL SYSTEM Carburetor Set-Up Specifications -2-Stroke Motors Pilot Screw Float Model No. Engine Displace Initial low Height/Drop Setting (Hp) ofCyl cu. ln. (cc) Setting ln. (mm) 6 90 LV 2-st 1997-03 158 (2596) 3/4 1 1/4 I!) 0.61-0.65 (1 5.5-16.5) 175 6 90 LV 2-st 1997-00 158 (2596) 13/16 -1 15/16 0.61-0.65 (15.5-16.5) 200 6 90 LV 2-st 1997-03 158 (2596} 7/8 -1 3/8 @ 0.61-0.65 (1 5.5-16.5) 225 6 90 LV 2-st 1997 158 (2596) 1/2 -1 (P), 11 1/2 (S) 0.61-0.65 (15.5-16.5) Initial low speed setting turn(s): back (counterclockwise) from a lightly seated position CD Specifications vary by carb position, top carb 1/2 -1, middle carb 1 1/2 -2, bottom carb 3/4 -1 1/4 Ž Specifications are for M model, the specification for W models is 1 1/8 -1 5/8 Valve Seat Size ln. (mm) 0.05 (1.2) 0.05 (1.2) 0.05 (1.2) 0.05 (1.2) Q) These specifications are for most 1997-03 models, Including those with the carburetor stamp mark 6H20A @) These specifications are for 1999 C60 Models, or 60FE/60FET, C60ER/C60TR models with the carburetor stamp mark 6H210 Ž Specifications vary more by model than by year, use these specs for C and P models (carburetor stamp marks 6H007 or 6H015) Ž Specifications vary more by model than by year, use these specs for A and E models ). Resistance in a circuit varies depending on the amount and type of components used in the circuit. The main factors that determine resistance are: • Material ˇ some materials have more resistance than others. Those with high resistance are said to be insulators. Rubber materials (or rubberlike plastics) are some of the most common insulators used, as they have a very high resistance to electricity. Very low resistance materials are said to be conductors. Copper wire is among the best conductors. Silver is actually a superior conductor to copper and is used in some relay contacts, but its high cost prohibits its use as common wiring. Most marine wiring is made of copper. • Size • the larger the wire size being used, the less resistance the wire will have ijust as a large diameter pipe will allow small amounts of water to just trickle through). This is why components that use large amounts of electricity usually have large wires supplying current to them. • Length ˇ for a given thickness of wire, the longer the wire, the greater the resistance. The shorter the wire, the less the resistance. When determining the proper wire for a circuit, both size and length must be considered to design a circuit that can handle the current needs of the component.• Temperature ˇwith many materials, the higher the temperature, the greater the resistance (positive temperature coefficient). Some materials exhibit the opposite trait of lower resistance with higher temperatures (these are said to have a negative temperature coefficient). These principles are used in many engine control sensors (especially those found on microcomputer controlled ignition and fuel injection systems). OHM'S LAW There is a direct relationship between current, voltage and resistance. The relationship between current, voltage and resistance can be summed up by a statement known as Ohm's law. Voltage (E) is equal to amperage (I) times resistance (R): E=l x R Other forms of the formula are R=EII and I=EIR In each of these formulas, E is the voltage in volts, I is the current in amps and R is the resistance in ohms. The basic point to remember is that if the voltage of a circuit remains the same, as the resistance of that circuit goes up, the amount of current that flows in the circuit will go down. The amount of work that electricity can perform is expressed as power. The unit of power is the watt (w). The relationship between power, voltage and current is expressed as: Power (W) is equal to amperage (I) times voltage (E): W=l x E This is only true for direct current (DC) circuits; the alternating current formula is a tad different, but since the electrical circuits in most vessels are DC type, we need not get into AC circuit theory. Electrical Components POWER SOURCE + See Figure 2 Typically, power is supplied to a vessel by two devices: The battery and the stator (or battery charge coil). The stator supplies electrical current anytime the engine is running in order to recharge the battery and in order to operate electrical devices of the vessel. The battery supplies electrical power during starting or during periods when the current demand of the vessel's electrical system exceeds stator output capacity (which includes times when the motor is shut off and stator output is zero}. IGNITION AND ELECTRICAL SYSTEMS 4-3 The Battery In most modern vessels, the battery is a lead/acid electrochemical device consisting of six 2-volt subsections (cells) connected in series, so that the unit is capable of producing approximately 12 volts of electrical pressure. Each subsection consists of a series of positive and negativeplates held a shortdistance apart in a solution of sulfuric acid and water. The two types of plates in each battery cell are of dissimilar metals. This sets up a chemical reaction, and it is this reaction which produces current flow from the battery when its positive and negative terminals are connected to an electrical load. Power removed from the battery in use is replaced by current from the stator and restores the battery to its original chemical state. The Stator Alternators and generators are devices that consist of coils of wires wound together making big electromagnets. The coil is normally referred to as a stator or battery charge coil. Ei.ther, one group of coils spins within another set (or a set of permanently charged magnets, usually attached to the flywheel, are spun around a set of coils) and the interaction of the magnetic fields generates an electrical current. This current is then drawn off the coils and fed into the vessel's electrical system. • Some vessels utilize a generator instead of an alternator. Although the terms are often misused and interchanged, the main difference is that an alternator supplies alternating current that Is changed to direct current for use on the vessel, while a generator produces direct current. Alternators tend to be more efficient and that is why they are used on almost all modern engines. GROUND Two types of grounds are used in marine electric circuits. Direct ground components are grounded to the electrically conductive metal through their mounting points. All other components use some sort of ground wire that STATOR OR RECTIFIEROR.. REGULATOR/ RECTIFIER BATTERYCHARGECOIL Fig. 2 Functional diagram of a typical charging circuit showing the relationship between the stator (battery charge coil), rectifier (or regulator/rectifier) and battery leads back to the battery. The electrical current runs through the ground wire and returns to the battery through the ground or negative (-) cable; if you look, you'll see that the battery ground cable connects between the battery and a heavy gauge ground wire. • A large percentage of electrical problems can be traced to bad grounds. If you refer back to the basic explanation of a circuit, you'll see that the ground portion of the circuit is just as important as the power feed. The wires delivering power to a component can have perfectly good, clean connections, but the circuit would fail to operate if there was a damaged ground connection. Since many components ground through their mounting or through wires that are connected to an engine surface, contamination from dirt or corrosion can raise resistance in a circuit to a point where it cannot operate. PROTECTIVE DEVICES Problems can occur in the electrical system that will cause large surges of current to pass through the electrical system of your vessel. These problems can be the fault of the charging circuit, but more likely would be a problem with the operating electrical components that causes an excessively high load. An unusually high load can occur in a circuit from problems such as a seized electric motor {like a damaged starter) or the excessive resistance caused by a bad ground (from loose or damaged wires or connections). A short to ground that bypasses the load and allows the battery to quickly discharge through a wire can also cause current surges. If this surge of current were to reach the load in the circuit, the surge could burn it out or severely damage it. It can also overload the wiring, causing the harness to get hot and melt the insulation. To prevent this, fuses, circuit breakers and/or fusible links are connected into the supply wires of the electrical system. These items are nothing more than a built-in weak spot in the system. When an abnormal amount of current flows through the system, these protective devices work as follows to protect the circuit: • Fuse ˇ when an excessive electrical current passes through a fuse. the fuse blows (the conductor melts) and opens the circuit, preventing current flow. • Circuit Breaker ˇ a circuit breaker is basically a selfˇrepairing fuse. It will open the circuit in the same fashion as a fuse, but when the surge subsides, the circuit breaker can be reset and does not need replacement. Most circuit breakers on marine engine applications are self-resetting, but some that operate accessories (such as on larger vessels with a circuit breaker panel) must be reset manually (just like the circuit breaker panels in most homes). • Fusible Link • a fusible link (fuse link or main link) is a short length of special, high temperature insulated wire that acts as a fuse. When an excessive electrical current passes through a fusible link, the thin gauge wire inside the link melts, creating an intentional open to protect the circuit. To repair the circuit, the link must be replaced. Some newer type fusible links are housed in plug-in modules, which are simply replaced like a fuse, while older type fusible links must be cut and spliced if they melt. Since this link is very early in the electrical path, it's the first place to look if nothing on the vessel works, yet the battery seems to be charged and is otherwise properly connected. ;c:... CAUTION Always replace fuses, circuit breakers and fusible links with identically rated components. Under no circumstances should a component of higher or lower amperage rating be substituted. A lower rated component will disable the circuit sooner than necessary (possibly during normal operation), while a higher rated component can allow dangerous amounts of current that could damage the circuit or component (or even melt insulation causing sparks or a fire). SWITCHES & RELAYS + See Figure 3 Switches are used in electrical circuits to control the passage of current. The most common use is to open and close circuits between the battery and the various electric devices in the system. Switches are rated according to the amount of amperage they can handle. If a sufficient amperage rated switch is not used in a circuit, the switch could overload and cause damage. 4ˇ4 IGNITION AND ELECTRICAL SYSTEMS Some electrical components that require a large amount of current to operate use a special switch called a relay. Since these circuits carry a large amount of current, the thickness of the wire in the circuit is also greater. If this large wire were connected from the load to the control switch, the switch would have to carry the high amperage load and the space needed for wiring in the vessel would be twice as big to accommodate the increased size of the wiring harness. A relay is used to prevent these problems. Think of relays as essentially ˇremote controlled switches." They allow a smaller current to throw the switch that operates higher amperages devices. Relays are composed of a coil and a set of contacts. When current is passed through the coil, a magnetic field is formed that causes the contacts to move together, closing the circuit. Most relays are normally open, preventing current from passing through the main circuit until power is applied to the coil. But, relays can take various electrical forms depending on the job for which they are intended. Some common circuits that may use relays are horns, lights. starters, electric fuel pumps and other potentially high draw circuits. LOAD Every electrical circuit must include a load (something to use the electricity coming from the source). Without this load, the battery would attempt to deliver its entire power supply from one pole to another. This is called a short circuit. All this electricity would take a short cut to ground and cause a great amount of damage to other components in the circuit (including the battery) by developing a tremendous amount of heat. This condition could develop sufficient heat to me.. the insulation on all the surrounding wires and reduce a multiple wire cable to a lump of plastic and copper. A short can allow sparks that could ignite fuel vapors or other combustible materials in the vessel, causing an extremely hazardous condition. WIRING & HARNESSES The average vessel contains miles of wiring, with hundreds of individual connections. To protect the many wires from damage and to keep them from becoming a confusing tangle, they are organized into bundles, enclosed in plastic or taped together and called wiring harnesses. Different harnesses serve different parts of the vessel. Individual wires are color coded to help trace them through a harness where sections are hidden from view. Marine wiring or circuit conductors can be either single strand wire, multistrand wire or printed circuitry. Single strand wire has a solid metal core and is usually used inside such components as stator coil windings, motors, relays and other devices. Multi-strand wire has a core made of many small strands of wire twisted together into a single conductor. Most of the wiring in a marine electrical system Is made up of multi-strand wire, either as a single conductor or grouped together in a harness. All wiring is color coded on the insulator, either as a solid color or as a colored wire with an identification stripe. A printed circuit is a thin film of copper or other conductor that is printed on an insulator backing. Occasionally, a printed circuit is sandwiched between two sheets of plastic for more protection and flexibility. A complete printed circuit, consisting of conductors, insulating material and connectors is called a printed circuit board. Printed circuitry is used in place of individual wires or harnesses in places where space is limited, such as behind 1-piece instrument clusters. Since marine electrical systems are very sensitive to changes in resistance, the selection of properly sized wires is critical when systems are repaired. A loose or corroded connection or a replacement wire that is too small for the circuit will add extra resistance and an additional voltage drop to the circuit. The wire gauge number is an expression of the cross-section area of the conductor. Vessels from countries that use the metric system will typically describe the wire size as ijs cross-sectional area in square millimeters. In this method, the larger the wire. the greater the number. Another common system for expressing wire size is the American Wire Gauge (AWG) system. As gauge number increases. area decreases and the wire becomes smaller. Using the AWG system, an 18 gauge wire is smaller than a 4 gauge wire. A wire with a higher gauge number will carry less current than a wire with a lower gauge number. Gauge wire size refers to the size of the strands of the conductor, not the size of the complete wire with insulator. It is possible, therefore, to have two wires of the same gauge with different diameters because one may have thicker insulation than the other. SWITCH B+r--!t-----.1------.., I 85 JO I I BaAY I I ICOILI1 as e1 1L--1----J------J GROUND CONPONENT RELAY SWITCH Fig. 3 Relays are composed of a coil and a switch. These two components are linked together so that when one is operated it actuates the other. The large wires in the circuit are connected from the battery to one side of the relay switch (B+) and from the opposite side of the relay switch to the load (component). Smaller wires are connected from the relay coil to the control switch for the circuit and from the opposite side of the relay coil to ground It is essential to understand how a circuit works before trying to figure out why it doesn't. An electrical schematic shows the electrical current paths when a circuit is operating properly. Schematics break the entire electrical system down into individual circuits. In most schematics no attempt is made to represent wiring and components as they physically appear on the vessel; switches and other components are shown as simply as possible. But, this is not always the case on Yamaha schematics and some of the wiring diagrams provided here. So, when using a Yamaha schematic if the component in question is represented by something more than a small square or rectangle with a label, it is likely a intended to be a representation of the actual componenrs shape. On most schematics, the face views of harness connectors show the cavity or terminal locations in all multi-pin connectors to help locate test points. Test Equipment Pinpointing the exact cause of trouble in an electrical circuit is usually accomplished by the use of special test equipment, but the equipment does not always have to be expensive. The following sections describe different types of commonly used test equipment and briefly explains how to use them in diagnosis. In addition to the information covered below, be sure to read and understand the tool manufacturer's instruction manual (provided with most tools) before attempting any test procedures. JUMPER WIRES + See Figure 4 7r' ;ˇ CAUTION Never use jumper wires made from a thinner gauge wire than the circuit being tested. If the jumper wire is of too small a gauge, it may overheat and possibly melt. Never use jumpers to bypass high resistance loads In a circuit. Bypassing resistances, in effect, creates a short circuit. This may, in turn, cause damage and fire. Jumper wires should only be used to bypass lengths of wire or to simulate switches. Jumper wires are simple, yet extremely valuable, pieces of test equipment. They are basically test wires that are used to bypass sections of a circuit. Although jumper wires can be purchased, they are usually fabricated from lengths of standard marine wire and whatever type of connector (alligator clip, spade connector or pin connector) that is required for the particular application being tested. In cramped, hard-to-reach areas, it is advisable to have insulated boots over the jumper wire terminals in order to prevent accidental grounding. It is also advisable to include a standard marine fuse in any jumper wire. This is commonly referred to as a fused jumper. By inserting an in-line fuse holder between a set of test leads, a fused jumper wire is created for bypassing open circuits. Use a 5-amp fuse to provide protection against voltage spikes. ˇ.ˇˇˇˇ .. . ˇ. ; . IGNITION AND ELECTRICAL SYSTEMS 4-5 Jumper wires are used pri marily to locate open electrical circuits, on either the ground (ˇ) side of the circuit or on the power (+) side. If an electrical component fails to operate, connect the jumper wire between the component and a good ground. If the component operates only with the jumper installed, the ground circuit is open. If the ground circuit is good, but the component does not operate, the circuit between the power feed and component may be open. By moving the jumper wire successively back from the component toward the power source, you can isolate the area of the circuit where the open is located. When the component stops functioning, or the power is cut off, the open is in the segment of wire between the jumper and the point previously tested. You can sometimes connect the jumper wire directly from the battery to the hot terminal of the component, but first make sure the component uses a full 12 volts in operation. Some electrical components, such as sensors, are designed to operate on smaller voltages like 4 or 5 volts, and running 12 volts directly to these components can damage or destroy them. TEST LIGHTS + See Figure 5 The test light is used to check circuits and components while electrical current is flowing through them. It is used for voltage and ground tests. To use a 12-volt test light, connect the ground clip to a good ground and probe connectors the pick where you are wondering if voltage is present. The test light will illuminate when voltage is detected. This does not necessarily mean that 12 volts (or any particular amount of voltage) is present; it only means that some voltage is present. It is advisable before using the test light to touch its ground clip and probe across the battery posts or terminals to make sure the light is operating properly and to note how brightly the light glows when 12 volts is present. ".* WARNING Do not use a test light to probe electronic ignition, spark plug or coil wires, as the circuit is much, much higher than 12 volts. Also, never use a pick-type test light to probe wiring on electronically controlled systems unless specifically instructed to do so. Whenever possible, avoid piercing insulation with the test light pick, as you are inviting shorts or corrosion and excessive resistance. But, any wire insulation that is pierced by necessity, must be sealed with silicone and taped after testing. Like the jumper wire, the 12-volt test light is used to isolate opens in circuits. But, whereas the jumper wire is used to bypass the open to operate the load, the 12-volt test light is used to locate the presence or lack of voltage in a circuit. If the test light illuminates, there is power up to that point in the circuit; if the test light does not illuminate, there is an open circuit (no power). Move the test light in successive steps back toward the power source until the light in the handle illuminates. The open is between the probe and the point that was previously probed. The self-powered test light is similar in design to the 12-volt test light, but contains a 1.5 volt penlight battery in the handle. It is most often used in place of a multi-meter to check for open or short circuits when power is isolated from the circuit (thereby performing a continuity test) . The battery in a self-powered test light does not provide much current. A weak battery may not provide enough power to illuminate the test light even when a complete circuit is made (especially if there is high resistance in the circuit). Always make sure that the test battery is strong. To check the battery, briefly touch the ground clip to the probe: if the light glows brightly, the battery is strong enough for testing. • A self-powered test light should not be used on any electronically c ˇ ontrolled system or component. Even the small amount of electricity transmitted by the test light is enough to damage many electronic components. MULTI-METERS + See Figure 6 Multi-meters are extremely useful for troubleshooting electrical problems. They can be purchased in both analog or digital form and have a price range to suit nearly any budget. A multi-meter is a voltmeter, ammeter and ohmmeter (along with other features) combined into one instrument. It is often used when testing solid state circuits because of its high input impedance (usually 10 mega ohms or more). A highˇquality digital multiˇ meter or Digital Volt Ohm Meter (DVOM) helps to ensure the most accurate test results and. although not absolutely necessary for electronic components such as computer controlled ignition systems and charging systems, is highly recommended. A brief description of the main test functions of a multi-meter follows: • Voltmeter -the voltmeter is used to measure voltage at any point in a circuit or to measure the voltage drop across any part of a circuit. Voltmeters usually have various scales and a selector switch to allow metering and display of different voltage ranges. The voltmeter has a positive and a negative lead. To avoid damage to the meter, connect the negative lead to the negative (-) side of the circuit (to ground or nearest the ground side of the circuit) and connect the positive lead to the positive ( +) side of the circuit (to the power source or the nearest power source). This is mostly a concern on analog meters, as DVOMs are not normally adversely affected (as they are usually designed to take readings even with reverse polarity and display accordingly). Note that the negative voltmeter lead will always be black and that the positive voltmeter will always be some color other than black (usually red). • Ohmmeter -the ohmmeter is designed to read resistance (measured in ohms) in a circuit or component. Most ohmmeters will have a selector switch which permits the measurement of different ranges of resistance (usually the selector switch allows the multiplication of the meter reading by 10, 100, 1,000 and 10,000). Most modern ohmmeters (especially DVOMs) are autoranging which means the meter itself will determine which scale to use. Since ohmmeters are powered by an internal battery, the ohmmeter can be used like a self-powered test light. When the ohmmeter is connected, current from the ohmmeter flows through the circuit or component being tested. Since the ohmmeter's internal resistance and voltage are known values, the amount of current flow through the meter depends on the resistance of the circuit or component being tested. The ohmmeter can also be used to perform a continuity test for suspected open circuits. When using the meter for continuity checks. do not be concerned with the actual resistance readings. Zero resistance, or any ohm reading; indicates continuity in the Fig. 4 Jumper wires are simple, but valuable pieces of test equipment Fig. 5 A 12-volt test light is used to detect the presence of voltage in a circuit Fig. 6 Multi-meters are probably the most versatile and handy tools for diagnosing faulty electrical components or circuits . :::ˇˇ.. 4ˇ6_ IGNITION AND ELECTRICAL SYSTEMS circuit. Infinite resistance indicates an opening in the circuit. A high resistance reading where there should be none indicates a problem in the circuit. Checks for short circuits are made in the same manner as checks for open circuits, except that the circuit must be isolated from both power and normal ground. Infinite resistance indicates no continuity, while zero resistance indicates a dead short. :.-;k WARNING Never use an ohmmeter to check the resistance of a component or wire while there is voltage applied to the circuit. Voltage in the circuit can damage or destroy the meter. • Ammeter -an ammeter measures the amount of current flowing through a circuit in units called amperes or amps. At normal operating voltage, most circuits have a characteristic amount of amperes, called current draw that can be measured using an ammeter. By referring to a specified current draw rating, and then measuring the amperes and comparing the two values, you can determine what is happening within the circuit to aid in diagnosis. An open circuit, for example, will not allow any current to flow, so the ammeter reading will be zero. A damaged component or circuit will have an increased current draw, so the reading will be high. The ammeter is always connected in series with the tested circuit. All of the current that normally flows through the circuit must also flow through the ammeter; if there is any other path for the current to follow, the ammeter reading will not be accurate. The ammeter itself has very little resistance to current flow and, therefore, will not affect the circuit, but it will measure current draw only when the circuit is closed and electricity is flowing. Excessive current draw can blow fuses and drain the battery, while a reduced current draw can cause motors to run slowly, lights to dim and other components to not operate properly. Troubleshooting Electrical Systems When diagnosing a specific problem, organized troubleshooting is a must. The complexity of a modern marine vessel demands that you approach any problem in a logical, organized manner. There are certain troubleshooting techniques, however, which are standard: • Establish when the problem occurs. Does the problem appear only under certain conditions? Were there any noises, odors or other unusual symptoms? Isolate the problem area. To do this, make some simple tests and observations, and then eliminate the systems that are working properly. Check for obvious problems, such as broken wires and loose or dirty connections. Always check the obvious before assuming something complicated is the cause. • Test for problems systematically to determine the cause once the problem area is isolated. Are all the components functioning properly? Is there power going to electrical switches and motors? Performing careful, systematic checks will often turn up most causes on the first inspection, without wasting time checking components that have little or no relationship to the problem. • Test all repairs after the work is done to make sure that the problem is fixed. Some causes can be traced to more than one component, so a careful verification of repair work is important in order to pick up additional malfunctions that may cause a problem to reappear or a different problem to arise. A blown fuse, for example, is a simple problem that may require more than another fuse to repair. If you don't look for a problem that caused a fuse to blow, a shorted wire (for example) may go undetected and cause the new fuse to blow right away (if the short is still present) or during subsequent operation (as soon as the short returns if it is intermittent). Experience shows that most problems tend to be the result of a fairly simple and obvious cause, such as loose or corroded connectors, bad grounds or damaged wire insulation that causes a short. This makes careful visual inspection of components during testing essential to quick and accurate troubleshooting. Electrical Testing VOLTAGE + See Figure 7 This test determines the voltage available from the battery and should be the first step in any electrical troubleshooting procedure after visual inspection. Many electrical problems, especially on electronically controlled systems, can be caused by a low state of charge in the battery. Many circuits cannot function correctly if the battery voltage drops below normal operating levels. Loose or corroded battery cable terminals can cause poor contact that will prevent proper charging and full battery current flow. 1. Set the voltmeter selector switch to the 20V position. 2. Connect the meter negative lead to the battery's negative (-) post or terminal and the positive lead to the battery's positive (+) post or terminal. 3. Turn the ignition switch ON to provide a small load. 4. A well charged battery should register over 12 volts. If the meter reads below 11.5 volts, the battery power may be insufficient to operate the electrical system properly. Check and charge or replace the battery as detailed under Engine Maintenance before further tests are conducted on the electrical system. VOLTAGE DROP + See Figure 8 When current flows through a load, the voltage beyond the load drops. This voltage drop is due to the resistance created by the load and also by small resistances created by corrosion at the connectors (or by damaged insulation on the wires). Since all voltage drops are cumulative, the maximum allowable voltage drop under load is critical, especially if there is more than one load in the circuit. 1. Set the voltmeter selector switch to the 20 volts position. 2. Connect the multi-meter negative lead to a good ground. 3. Operate the circuit and check the voltage prior to the first component (load). 4. There should be little or no voltage drop in the circuit prior to the first component. If a voltage drop exists, the wire or connectors in the circuit are suspect. 5. While operating the first component in the circuit, probe the ground side of the component with the positive meter lead and observe the voltage readings. A small voltage drop should be noticed. This voltage drop is caused by the resistance of the component. 6. Repeat the test for each component (load) down the circuit. 7. If an excessively large voltage drop is noticed, the preceding component, wire or connector is suspect. RESISTANCE + See Figure 9 ˇ:, :l WARNING Never use an ohmmeter with power applied to the circuit. The ohmmeter is designed to operate on its own power supply. The normal 12ˇvolt electrical system voltage will damage or destroy many meters! 1. Isolate the circuit from the vessel's power source. 2. Ensure that the ignition key is OFF when disconnecting any components or the battery. 3. Where necessary, also isolate at least one side of the circuit to be checked, in order to avoid reading parallel resistances. Parallel circuit resistances will always give a lower reading than the actual resistance of either of the branches. 4. Connect the meter leads to both sides of the circuit (wire or component) and read the actual measured ohms on the meter scale. Make sure the selector switch is set to the proper ohm scale for the circuit being tested, to avoid misreading the ohmmeter test value . IGNITION AND ELECTRICAL SYSTEMS 4-7 1'11.A..TfHETER HULTIHETER MULTIH T R + -OSITI I: LEAD GATIVE LEAD BATTERY OHMS NEPOSITIVE LEAD GATIVE LEAD Fig. 7 A voltage check determines the amount of battery voltage available and, as such, should be the first step in any troubleshooting procedure Fig. 8 Voltage drops are due to resistance in the circuit, from the load or from problems with the wiring Fig. 9 Resistance tests must be conducted on portions of the circuit, isolated from battery power • The resistance reading of most electrical components will vary with temperature. Unless otherwise noted, specifications given are for testing under ambient conditions of sa•F (2o•c). If the component is tested at higher or lower temperatures, expect the readings to vary slightly. When testing engine control sensors or coil windings with smaller resistance (less than 1000 ohms) It is best to use a high quality be especially careful of your test results. Whenever possible, double-check your results against a known good part before purchasing the replacement. If theoldpartto the marine parts dealer and have them compare to prevent possibly replacing a good component. OPEN CIRCUITS + See Figure 10 This test already assumes the existence of an open in the circuit and it is used to help locate position of the open. 5. Isolate the circuit from power and ground. 6. Connect the self-powered test light or ohmmeter ground clip to the ground side of the circuit and probe sections of the circuit sequentially. 7. If the light is out or there is infinite resistance, the open is between the probe and the circuit ground. 8. If the light is on or the meter shows continuity, the open is between the probe and the end of the circuit toward the power source. SHORT CIRCUITS + See Figure 11 • Never use a self-powered test light to perform checks for opens or shorts when power is applied to the circuit under test. The test light can be damaged by outs1de power. 1. Isolate the circuit from power and ground. 2. Connect the self-powered test light or ohmmeter ground clip to a good ground and probe any easy-to-reach point inthe circuit. 3. If the light comes on or there is continuity, there is a short somewhere in the circuit. 4. To isolate the short, probe a test point at either end of the isolated circuit (the light should be on or the meter should indicate continuity). 5. Leave the test light probe engaged and sequentially open connectors or switches, remove parts, etc. until the light goes out or continuity is broken. 6. When the light goes out, the short is between the last two circuit components that were opened. Wire And Connector Repair Almost anyone can replace damaged wires, as long as the proper tools and parts are available. Wire and terminals are available to fit almost any need. Even the specialized weatherproof, molded and hard shell connectors used by many marine manufacturers. Be sure the ends of all the wires are fitted with the proper terminal hardware and connectors. Wrapping a wire around a stud is not a permanent solution and will only cause trouble later. Replace wires one at a time to avoid confusion. Always route wires in the same manner of the manufacturer. When replacing connections, make absolutely certain that the connectors are certified for marine use. Automotive wire connectors may not meet United States Coast Guard (USCG) specifications. • If connector repair is necessary, only attempt it if you have the proper tools. Weatherproof and hard shell connectors may require special tools to release the pins inside the connector. Attempting to repair these connectors with conventional hand tools will damage them. Electrical System Precautions • Wear safety glasses when working on or near the battery. • Don't wear a watch with a metal band when servicing the battery or starter. Serious burns can result if the band completes the circuit between the positive battery terminal (or a hot wire) and ground. • Be absolutely sure of the polarity of a booster battery before making connections. Remember that even momentary connection of a booster battery with the polarity reversed will damage charging system diodes. Connect the cables positive-to-positive, and negative (of the good battery)to- a good ground on the engine (away from the battery to prevent the possibility of an explosion if hydrogen vapors are present from the electrolyte in the discharged battery). Connect positive cables first (starting with the discharged battery), and then make the last connection to ground on the body of the booster vessel so that arcing cannot ignite hydrogen gas that may have accumulated near the battery. • Disconnect both vessel battery cables before attempting to charge a battery. • Never ground the alternator or generator output or battery terminal. Be cautious when using metal tools around a battery to avoid creating a short circuit between the terminals. • When installing a battery, make sure that the positive and negative cables are not reversed. • Always disconnect the battery (negative cable first) when charging. • Never smoke or expose an open flame around the battery. Hydrogen gas is released from battery electrolyte during use and accumulates near the battery. Hydrogen gas is highly explosive. 4-8 IGNITION AND ELECTRICAL SYSTEMS POSITIVE LEAD MULTIMETER OHMS NEGATIVE LEAD SWITCH SOlENOID Fig. 10 The easiest way to illustrate an open circuit is to picture a circuit in which the switch is turned OFF (creating an opening in the circuit) that prevents power from reaching the load IGNITION SYSTEMS + See Figure 12 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 operated every 3 to 4 weeks throughout the year. The carburetion and ignition principles of 2-stroke engine operation must be understood in order to perform a proper tuneˇup on an outboard motor. If you have any doubts concerning your understanding of engine operation, it would be best to study the operation theory before tackling any work on the ignition system. CDI/TCI Systems DESCRIPTION & OPERATION + See Figures 13 and 14 All Yamaha motors since 1995 are equipped with some form of the Yamaha Capacitor Discharge Ignition (CD I) or Transistor Controlled Ignition (TCI) electronic ignition systems. Some models are equipped with a microˇ computer controlled version of the system which means the CDI!TCI unit or ECM (as the unit is known on most fuel injected motors) utilizes additional input (sensor input such as a crank position sensor, knock sensor, temperature sensor or even oil level sensor on some 2-strokes) to help make spark timing decisions, however, the basic function of the various Yamaha ignition systems are all similar. The first thing these ignitions have in common is that a flywheel/magneto assembly is used to generate power/signals over pulser and/or charge (or stator) coils. In all cases, the power and signals are fed to a control unit which is used to trigger the ignition coils and spark plugs. Although the basic function of the components is the same across most systems, their actual jobs may be performed by different physical components on some motors or their functions may be combined into a single unit on some motors. Generally speaking, charge coils are used to generate system power, however, their function may be performed by the stator coil in some cases ftOSIT1VE LEADHULTIKETER OHMS .. .. LIGHT(ON) .. Fig. 11 In this illustration a load (the light) is powered when it should not be (since the switch should be creating an open condition), but a short to power (battery) is powering the circuit. Shorts like this can be caused by chaffed wires with worn or broken insulation Fig. 12 The ignition system must be properly adjusted and synchronized for optimum powerhead performance (either through dedicated charge coil windings in the stator coil or possibly even by the lighting coil windings when separate charge coil windings are not provided). Similarly, pulser coils are normally used to generate signals triggering the CDI/TCI unit to fire the ignition coils, however on some single cylinder models no pulser coil is needed, as the plugs are fired each time the charge coil generates power. The CDI/TCI unit takes in power from the charge coil (or stator) and signals from the pulser coil(s) and then uses the power and signals to control function of the ignition coils. While fuel injected motors may combine the function of the CDI!TCI unit with the Electronic Control Module (ECM) which also controls the fuel injection system. .ˇ . .. COIL CHARGE CO IL HIGH SPEED IGNITION AND ELECTRICAL SYSTEMS 4-9 DIODE CAPAC ITOR Fig. 13 Functional diagram of a typical Yamaha CDI ignition system PULSAR LOW SPEED CHARGE COIL Fig. 14 Functional diagram of a Yamaha CDI ignition system with separate lowˇ and high-speed charge coils ˇ V4 and V6 carbureted powerheads To understand any one Yamaha motor's ignition system, refer to the system descriptions below. If you have any doubt as to the components utilized by a given motor, please referto the Wiring Diagrams and the Ignition System Component testing charts in this section as well. • Throughout this section we'll refer to the CD! unit when talking about the CD! unit, TCI unit or ECM, whichever Is responsible for the Ignition cont.rol module. Don't be confused If you're researching a TCI motor and we're calling it CDI, that's justto keep from having to constantly write (and for you to constantly read "CDI/TCI unit or ECM"). 1-Cylinder Ignition The CDI and TCI systems found on single-cylinder Yamaha motors are among the simplest forms of an ignition system and are composed of the following elements: • Magneto • Pulser coil • Charge, or source coil • Igniter (CDI!fCI) box • Ignition coil • Spark plug Other components such as main switches, stop switches, or computer systems may be included, though, these items are not necessary for basic CDI operation. To understand basic CD! operation, it is important to understand the basic theory of induction. Induction theory states that if we move a magnet (magnetic field) past a coil of wire (or the coil by the magnet), AC current will be generated in the coil. The amount of current produced depends on several factors: • How fast the magnet moves past the coil • The size of the magnet (strength) • How close the magnet is to the coil • Number of turns of wire and the size of the windings The current produced in the charge coil goes to the CDI box. On the way in, it is converted to DC current by a diode. This DC current is stored in the capacitor located inside the box. As the charge coil produces current, the capacitor stores it. At a specific time in the magneto's revolution, the magnets go past the pulser coil (which is usually just a smaller version of the charge coil, so it has less current output). The current from the pulser also goes into the CDI box. This current signals the CDI box when to fire the capacitor (the pulser may be called a trigger coil for obvious reasons). The current from the capacitor flows out to the ignition coil and spark plug. The pulser acts much like the points in older ignitions systems. When the pulser signal reaches the CDI box, all the electricity stored in the capacitor is released at once. This current flows through the ignition coil's primary windings. The ignition coil is a step-up transformer. It turns the relatively low voltage entering the primary windings into high voltage at the secondary windings. This occurs due to a phenomena known as induction. The high voltage generated in the secondary windings leaves the ignition coil and goes to the spark plug. The spark in turn ignites the air-fuel charge in the combustion chamber. Once the complete cycle has occurred, the spinning magneto immediately starts the process over again. Main switches, engine stop switches, and the like are usually connected on the wire in between the CDI box and the ignition coil. When the main switch or stop switch is turned to the OFF position. the switch is closed. This closed switch short-circuits the charge coil current to ground rather than sending it through the CDI box. With no charge coil current through the CD! box, there is no spark and the engine stops or, if the engine is not running, no spark is produced. The ignition systems on Yamaha single-cylinder motors vary as follows: • 2 hp motors: utilize a single charge coil (no pulser coil as the CDI unit fires each time a voltage is generated). • 3ˇ5 hp motors: utilize a lowˇ and high-speed pulser coils in addition to the balance of the standard CDI ignition components. 2-Cylinder Ignition Yamaha produces 2-cylinder outboards ranging from smaller 6 hp units, all the way up to larger 48 hp motors. These outboards are usually, though not always, equipped with one, dual-lead ignition coil. In addition to the dual-lead ignition coil, the system typically uses one pulser coil (though there are a few motors that use dual pulser coils}, one charge coil and a CD! box. • Normally, the 20/25 hp (395cc} and 25/30 hp (496cc} motors are equipped with dual pulser coils. When equipped with only one pulser coil, both spark plugs are fired at the same time. Although both cylinders spark at the same time, only one cylinder is actually producing power. The crankshaft is a t 80 degree type which means that as piston number one is at top dead center. piston number two is at bottom dead center. The piston at TDC is compressing a fuel charge that the spark then ignites. At the same moment, the piston at BDC isn't compressing a fuel charge. Actually, there are still exhaust gases going out. The spark in this cylinder has no effect on power production. This combination of engine and ignition design is called waste spark system (which is something as a misnomer, because no efficiency is actually lost by the spark in the non-compressed cylinder). After the crankshaft has rotated another 180 degrees, the two pistons have reversed position. The spark fires again to ignite the fuel charge compressed in cylinder number two and sparks to no effect in cylinder one. Twin coil CDI operation up to the ignition coil is exactly like the basic CDI. The difference simply comes in the utilization of the dual-lead ignition coil On a traditional ignition coil, the current leaves the coil, goes to the spark plug, then through the cylinder head to ground. On a dual-lead coil, the current leaves the coil, goes through one of the spark plugs, travels through the cylinder head to the second spark plug, and returns to the coil itself. This way one coil can fire two cylinders. 4-10 IGNITION AND ELECTRICAL SYSTEMS This type of system requires about 30% more voltage than a standard system to fire the second spark plug. This is because more energy is required for the spark to jump from the bridge of the spark plug to the center electrode. • If this system has weak spark, the first sign is the second spark plug will not having a hot enough spark. This plug will foul even thoughthe other plug is working fine. A quick check to tell if the plug fouling on one cylinder is due to weak ignition is to switch the ignition coil leads. If the plug fouling goes to the other cylinder, weak ignition components are the problem. 3ˇCylinder Ignition Three-cylinder models can be divided into three groups: • Units with 3 pulsar coils • Units with 2 pulsar coils (without Microcomputer control) • Units with 1 pulsar coil (with Microcomputer control) Models equipped with three pulsar coils use one pulsar for each cylinder. The pulsars are spaced 120 apart. As each pulsar produces its own signal, the COl box fires the ignition coil for thatcylinder. The largest of the 3-cylinder engine families (the 65J-90 hpf1140cc motors) have two items that make them unique to other Yamaha 3-cylinder engines. One, they have 2 charge coils, one called a low-speed charge coil and the other called the high-speed charge coil. And rather than having separate large coils, these motors normally have both charge coils and the lighting coil combined into a single unit called a stator. • Thefailure of anyof these coils will result in the replacement of the whole stator ratherthan a single coil. The second unique feature to the 65J-90 hp (1140cc} motor family is that it sometimes uses 2 pulsar coils rather than three. Some 3-cylinder motors use 1 pulsar per cylinder, but in this case, 1 pulsar actually controls 2 cylinders, however, these 2 cylinders are not firing at the same time like the earlier twin models. In order to allow 2 cylinders to fire off 1 pulsar atdifferent times, the pulsar must tell the COl box when to ignite the appropriate cylinder. This is accomplished by taking advantage of a characteristic of the induction process. As a magnet goes by the pulsar, electricity is generated. This current flows to the igniter (COl) box. The direction the current flows is determined by which end (north or south) of the magnet travels past the coil first. When the north end goes by the coil, current flows in one direction. When the south end of the magnet goes by, the current flows in the opposite direction. This is sometimes referred to as phase or polarity. The COl box can differentiate the direction of current flow and direct the signal to the appropriate capacitor. The COl box, in effect, knows which cylinder to fire by the signature of the signal. On models with microcomputer control there is 1 pulsar coil, but there is also a Crankshaft Position Sensor (CPS). In some cases the pulsar fires the 1 & 3 cylinders while the computer calculates positioning of the #2 cylinder for firing purposes. In these cases a failure of the microcomputer circuitry may extinguish the #2 spark. In all cases, the CPS provides data to the COl unit which is used to control spark timing curves. Carbureted V4 & V6 Ignition The V4 ignition system works like a basic COl system with two major differences. First, 1 pulsar fires 2 cylinders independently of each other. Second, there are 2 charge coils, a low-speed winding and a high-speed coil winding, both of which are incorporated into the stator assembly. The pulsar coils are installed on their own sensor plate, underneath the stator. In the most basic COl systems, 1 pulsar coil sends the signal to fire one ignition coil. In the V4 system 2 pulsar coils fire for separate ignition coils. This means that one two-wire pulsar coil fires two separate cylinders at different times in the firing order. In order to fire two cylinders off 1 pulsar at different times, the pulsar must tell the COl box when to fire a particular cylinder. This is accomplished by inducing distinctly different electrical signals foreach pulsar. When a magnet passes a pulsar, electricity is generated. This current flows tothe COl box. The direction of current flow (sometimes referred to as phase) is determined by which end of the magnet, north orsouth, travels past the coil first. When the north end goes by the pulsar coil first, current flows in one direction. When the south end of the magnet goes by first, the current flows in the opposite direction. The CDI box senses which direction the pulsar current is flowing. The direction of flow determines which of the two cylinders controlled by that pulsar will fire. By operating this way, two pulsars can control the operation of four cylinders. In a basic COl system, a single charge coil is used to supply the electrical power needed for the ignition. On larger Yamaha outboards, 2 charge coils are used to supply the electrical needs of the ignition system. On these COl systems, the low speed, high-speed, and lighting coils are all combined into one unit called a stator. If any of the stator components are bad, the whole assembly is replaced. The V6 ignition is very similar to the V4 system. The V6 systems have the same low-and high-speed charge coils for better electrical output at all speeds. The first major difference is that the V6 uses either 2 pulsar coils to fire 6 cylinders (injected models and 2250ET pre-mix motors) or 3 pulsar coils to fire 6 cylinders (pre-mix motors, except the 225DET). These pulsars operate on the same principle as the V4 pulsars. The second major difference is that the V6 is normally equipped with a microcomputer controlled ignition. This system utilizes additional input from a thermo-switch, an oil level sensor (oil injection models) and, a crankshaft position sensor. Additionally, this ignition contains a self-diagnosis system capable of displaying trouble-codes in the case of a microcomputer ignition circuit fault. For more information on the microcomputer control portion of this system, please refer to the Yamaha Microcomputer Ignition System later in this section. EFifHPDIV4 & V6 Ignition EFI OX66 motors are equipped with 6 individual pulsar coils (one per cylinder) mounted to a pulsar coil plate, located below the stator. Power for the ignition comes from low-and high-speed charge coil windings which are incorporated into a stator assembly along with the lighting coil windings. Microcomputer control happens at an ECMfCDI unit and includes input from a CPS, WTS, TPS, thermo-switches, oil level sensor and knock sensor (on 3.1 L engines). HPDI motors are similar totheir EFI OX66 counterparts (also using 6 individual pulsar coils). However, power for the system on these units comes from the stator coil lighting coil windings and not dedicated charge coil windings. Microcomputer control takes into consideration virtually all sensors of the HPDI system including the IAT, WTS, APS, FPS, TPS, water detection switch, oil level sensor and thermo-switch (no knock sensor is used on these motors). Charge Circuit POWER FOR THE IGN/170N + See Figures 15, 16 and 17 Two basic circuits are used with the CDI/TCI system; the first of these is the charge circuit. The charge circuit typically consists of the flywheel magnet, a charge coil (or lighting coil on some models), a diode (usually contained within the CDI unit), and a capacitor (also within the CDI unit). As the flywheel magnet passes by the charge coil, a voltage is induced in the coil windings. As the flywheel continues to rotate and the coil is no longer influenced by the magnet, the magnetic field collapses. Therefore, an alternating current is produced at the charge coil. This AC current is changed to DC by a diode inside the CDI unit. • A diode is a solid state unit which permits current to flow inone direction but prevents flow in the opposite direction. A diode may also be known as a rectifier. The current then passes to a capacitor, also located inside the COl unit, where it is stored. Most V4 and V6 models have two charge coils (low-speed and highspeed coils). A voltage is induced in the windings of each coil. It is not clear whether the coils actually function at different speeds or just function differently, at different speeds. The magnitude of the voltage depends upon the number of windings (turns) in each coil and the engine rpm. The voltages generated by these two charge coils are limited by a voltage regulator and stored separately in two condensers. The condensers are charged in stages, each time a magnet passes a charge coil. IGNITION AND ELECTRICAL SYSTEMS 4-11 Fig. 15 Example of a Yamaha stator platewith 1 pulser, 1 charge and 1 lighting coil. The stator plate is rotated through the joint link to advance the timing Fig. 16 Stator plate from a typical multiˇ cylinder motor (this onewith 3 pulser coils, 1 charge and one lighting coil) Fig. 17 The COl unit utilizes output from the charge coil to power the ignition coils POWER FOR ACCESSORIES + See Figure 18 The batte y charging system consists of the flywheel magnets, a lighting coil (the outboard equivalent of an alternator), a rectifier, voltage regulator (on some motors), and the battery. .The lighting coil, so named because it may be used to power the hghts on the boat when used together with a rectifier (or regulator/rectifier), allows the powerhead to generate additional electrical current to charge the battery. As the flywheel magnets rotate. voltage is induced in the li..hting coil (either a separate coil located next to t..e pul.ser co1ls, or the hghtmg coil windings may be found in the stator coil). Th1s alternating current through a series of diodes ..nd e..erges as. DC current. .may be stored in the battery. A lighting coil may be Identified by clean lam1..ated copper windings (all other coils are normally wrapped 1n tape and theJr . windings are not visible) or by the wire colors. On Yamaha motors the light coil wiring is normally Green/White and/or Gr..en on these m..tors. For details on a specific motor, refer to the Charg1ng System Testmg charts and/or the Wiring Diagrams found in this section. The rectifier converts the Alternating Current (AC) voltage into DC voltage, which may then be stored in the battery. "!'he re..tifier is .. sealed unit and generally contains four diodes. If one of the d1odes IS defecnve, the entire unit must be replaced. When equipped, the voltage regulator stabilizes the power of the coils and extends the life of the light bulbs and battery by powersurges or overcharging. Fig. 18 The charge and lighting coil (stator) removed from a V6 powerhead for bench testing Pulser Circuit + See Figure 19 The second circuit used in CDI!TCI systems is the pulser circuit. The pulser circuit usually has its own flywheel magnet (or magnets). one or more pulser coils, a diode, and a thyristor. Those la. st 2 components (thynstor ..nd diode) are internal components to. the umt. ln .case you were.wondenng, a thyristor is a solid state electromc dev1ce wh1ch perm1ts vonage to flow only after it is triggered by another voltage sour... At the point in time when the ignition timing marks ahgn, an current is induced in the pulser coil, in the same manner as prev1ously .described for the charge coil. This current is then passed to a second d1ode located in the CDI unit where it becomes DC current and flows on to the thyristor. This voltage triggers the thyristor to permit the voltage stored in the capacitor to be discharged. The volta .ge...asse.. through the thyristor and on to the primary of the 1gm!Jon co1l. In this manner, a spark at the plug may be accurately timed by the tim.ingmarks on the flywheel relative to the magnets in the flywheel and to prov1de as many as 100 sparks per second for a powerhead ope....ting at 6000 rpm. Different ignition strategies on Yamaha motors may ut11ize as .many as 6 pulser coils (up to one per cylinder) on V6 motors or 2 pul. ser coils o.. a . .single cylinder motor (on which the compos1te wave form ..s use? for Jg..111on control). Differences are spelled out as clearly as we can m eart1er on Ignition by motor type (and in the Ignition System Component testing charts and Wiring Diagrams, in this section). Fig. 19 A typical Yamaha 3-pulser coil assembly 4-12 IGNITION AND ELECTRICAL SYSTEMS Ignition Coils • See Figure 20 Yamaha ignition coils, usually one per cylinder or one per pair of cylinders, boost the DC voltage instantly to over 20,000 volts (and potentially as much as 50,000 volts) for spark. This completes the primary side of the ignition circuit. Once the vottage is discharged from the ignition coil, the secondary circuit begins and only stretches from the ignition coil to the spark plugs via extremely large high tension leads. At the spark plug end, the voltage arcs in the form of a spark, across from the center electrode to the outer electrode, and then to ground via the spark plug threads. This completes the ignition circuit. Ignition Timing At the point in time when the ignition timing marks align, an alternating current is induced in the pulser coil, in the same manner as previously described for the charge coil. This current is then passed to a second diode located in the CDI unit where it becomes DC current and flows on to the thyristor. This voltage triggers the thyristor to permit the voltage stored in the capacitor to be discharged. The capacitor voltage passes through the thyristor and on to the primary windings of the ignition coil. In this manner, a spark at the plug may be accurately timed by the timing marks on the flywheel relative to the magnets in the flywheel and to provide as many as 1 00 sparks per second for a powerhead operating at 6000 rpm. Units equipped with an automatic advance type CDI/TCI system have no moving or sliding parts. Ignition advance is accomplished electronically -by the electric waves emitted by the pulser coils. These coils increase their wave output proportionately to engine speed increase, thus advancing the timing. Units equipped with a mechanical advance type CDI system use a link rod between the carburetor and the ignition base plate assembly. At the time the throttle is opened, the ignition base plate assembly is rotated by means of the link rod, thus advancing the timing. Ignition and Charging System Troubleshooting Accurate troubleshooting of an ignition system is viewed by many as mission impossible. But this really does not have to be the case. Having a systematic approach to troubleshooting is the key. Your first priority is to understand how the system works. Fig. 20 Most Yamaha motors utilize one ignition coil for each cylinder Get yourself mentally prepared for ignition troubleshooting before you touch the motor. Make notes about how the motor behaves. Is it totally dead? Misfiring? If it is dead, what were the circumstances that led to its demise? Did it run poorly before it died? If it is running, but not well, is this a permanent condition? Only when cold? Only when warm? Under load? Ask yourself a lot of questions. The more information you can gather the faster the repair can be made. It is easy to forget to ask yourself if the root cause of the failure is truly ignition? Could it be something else? look at the plug and check the spark. Once you have done the basics, the hands-on troubleshooting begins. The key to successful troubleshooting is a systematic approach. Do not skip around. On new or unfamiliar equipment try writing up a check list on a 3 x 5 note card. This makes a handy reference for future troubleshooting. Use a spark tester to observe spark quality. Does it jump the gap? Is it Blue? Orange spark usually means trouble in the ignition system. Do not forget to check the ignition controlling components such as the main or stop switches. These can be disconnected from the system. These switches can cause failures that checks of the individual ignition components may not reveal. Motors with microcomputer controlled ignition systems utilize other sensor inputs to help determine spark timing. A thermo-switch or oil level sensor giving an incorrect reading may prevent spark timing advance. Don't forget these and other ignition control sensors. Always attempt to proceed with the troubleshooting in an orderly manner. The shot in the dark approach will only result in wasted time, incorrect diagnosis, replacement of unnecessary parts, and frustration. COMPONENT TESTING Resistance Testing Precautions When performing an electrical resistance test on a CDI/TCI unit, rectifier unit, or any device where the resistance varies with electrical polarity or applied voltage the following points should be noted: • There are no standard specifications for the design of either analog or digital test meters. • When performing resistance testing, some test meter manufacturers will apply positive battery power to the Red test lead, while others apply the positive voltage to the Black lead. • Some meters (especially digital meters) will apply a very low voltage to the test leads that may not properly activate some devices (e.g., CDI units). • Be aware there are ohmmeters that have reverse polarity. If your test results all differ from the chart, swap + and -leads and retest. • Digital meter resistance values are not reliable when testing COl units, rectifier units, or any device containing semiconductors, transistors, and diodes. • Although resistance test specifications can be helpful, they are also very misleading in ignition circuits/components. A component may test within specification during a static resistance check, yet still fail during normal operating conditions. Also, remember that readings will vary both with temperature and by meter. Spark Plugs • See Figures 21, 22 and 23 1. Check the plug wires to be sure they are properly connected. Check the entire length of the wires from the plugs to the magneto under the stator plate. If the wires are 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 by hand. This is a rough test to determine if the plug is tightened properly. The attempt to loosen the plug by hand should fail. The plug should be tight and require the proper socket size tool. Remove the spark plug and evaluate its condition. Reinstall the spark plug and tighten with a torque wrench to the proper specffication. 3. Use a spark tester and check for spark. If a spark tester is not available (and for Pete's sake they're cheap and can be found in almost all auto parts stores) hold the plug wire about 1/4 in. (6.4mm) from the engine (leave the plug in the port for safety). Carefully operate the 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 IGNITION AND ELECTRICAL SYSTEMS 4-13 Fig. 21 Disconnect the spark plug wire ... Fig. 22 •••and check spark using a tester Fig. 23 Remove and inspect the spark plug order to ignite the air-fuel mixture in the cylinder. This means rt is possible to think a strong spark is present. 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. Compression + See Figure 24 Before spending too much time and money attempting to trace a problem to the ignition system, a compression check of the cylinder should be made. If the cylinder does not have adequate compression, troubleshooting and attempted service of the ignition or fuel system will fail to give the desired results of satisfactory engine performance. For details, please refer to Compression Testing in the Maintenance and TuneˇUp section. Polarity Check + See Figure 25 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, or on most CDI/TCI systems, there will be no spark. Under such demanding conditions, in a very short time the coil would be unable to supply enough voltage to fire the The polarity of the coil can be checked using an ordinary analog D.C. voltmeter set on the maximum scale. Connect the positive lead to a good ground. With the engine running, momentarily touch the negative lead to a spark plug tenninal. The needle should swing upscale. If the needle swings downscale, the polarity is reversed. 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 in. (6.35mm) from the spark plug tenninal. 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. The firing end of a used spark plug can give a clue to coil polarity. If the ground electrode is dished, it may mean polarity is reversed. Pulser Coils + See Figures 26 thru 30 There are basically 2overall methods used in testing pulser coils. a static resistance check and a dynamic cranking or running output voltage check. Specifications vary by year and model so significantly that it precludes trying to list them in this procedure. In addition, the method of conducting the static check will vary wrth the specifications that are provided. Generally speaking cranking or running tests are more accurate and more likely to show intermittent problems. Dynamic checks are done under different circumstances, with load (circuit complete) and without load (circuit incomplete). again, depending upon the specifications provided by the determine coil polarity. specification charts in this section for details. Fig. 24 Preparing to check powerhead cranking compression. Note the jumper leads used to ground the cylinders Fig. 25 Checking ignition coil polarity with an analog voltmeter Fig. 26 Example of Lowˇ and high-speedpulser coils mounted on 3ˇ5 hp powerheads plugs. Any one of the following three methods may be used to quickly manufacturer. Please refer to the Ignition System Component Testing ˇ.-.ˇ.-ˇˇ ..._ .. _ 4-14 IGNITION AND ELECTRICAL SYSTEMS Fig. 30 Coil testing may include cranking or running voltage andfor resistance tests (this shows a typical resistance test) • If you're in doubt about any test connections verify them using the information in the Ignition Component Testing specifications charts AND the Wiring Diagrams, found in this section. The basic test for a pulsar coil is continuity. This measures the actual . resistance from one end of the pulsar coil to the other. When available, the correct specilication for each coil can be found in the Ignition Testing Specifications charts. 4. Adjust the meter to read resistance (ohms). 5. Connect the tester across the pulser leads (as noted in the testing charts andfor the wiring diagrams) and note the reading. 6. Compare the coil reading to the specifications. 7. If the reading is well above or below the correct value it should be checked dynamically (if output specifications are available) andfor be replaced. • Remember that temperature has an affect on resistance. Most resistance specifications are given assuming a temperature of sa•F (2oˇq. Fig. 29 Testing a pulser coil -most 2- cylinder powerheads There are two types of pulser coils. The first type has one coil lead connected directly to ground through a Black wire or a grounded bolt hole. The other end of the coil has a color-coded wire. These type coils have one lead listed as Black and the other typically a White wire with a colored tracer. The other type of pulser coil is not grounded at the powerhead. Instead, both leads go to the COl box. Both coil leads are often White with a colored tracer. When checking either type pulser coil for continuity, connect the ohmmeter to the color wires listed in the Ignition Testing Specifications chart. A second check must be made on pulsar coils ihat are not grounded on one end. This second check is called a short-to-ground check. Make sure that this type of coil not only has correct resistance (continuity) but also is not shorted to ground (and leaking current to ground). 8. Connect one tester lead to a coil lead. 9. Touch the other tester lead to the engine ground orthe mounting point of the pulser. 10. If the pulsar is good, the reading on the ohmmeter should be infinity. 11. Any ohm reading other than infinity (O.L on some digital meters) indicates a bad coil. Repair or replace the coil. • This second check is just as critical as the standard continuity check. The final. and most important check, is a dynamic cranking or running output voltage check. If specifications are provided, proceed as follows: 12. Set the meter to read volts in the proper scale (as determined by the specification range in the chart). 13. Connect the meter to the pulser coillead(s) under the appropriate conditions. For with load specifications the circuit must be complete meaning you'll have to either back-probe the wiring harness or (if this cannot be done without damaging the connectors) use jumper wires between the disconnected ends of the harness. For without load specifications you can just disconnect the harness and probe the coil sides. 14. If the coil fails to produce sufficient voltage for specifications, doublecheck all connections and wire colors. Once you are certain the coil isout of spec it must be replaced. Charge Coils + See Figures 31, 32 and 33 The charge coil checks are essentially the same as those for the pulser coil. There are normally 2 methods used in testing charge coils, a static resistance check and a dynamic cranking or running output voltage check. Specifications vary by year and model so significantly that it precludes trying to list them in this procedure. In addition, the method of conducting the static check will vary with the specifications that are provided. Generally speaking cranking or running tests are more accurate and more likely to show intermittent problems. Dynamic checks are done under different IGNITION AND ELECTRICAL SYSTEMS 4-15 Fig. 31 Locate the charge coil leads..• Fig. 32 .•.then conduct static (ohm) . . . Fig. 33 .•.and/or dynamic (voltage) tests circumstances, with load (circuit complete) and without load (circuit incomplete), again, depending upon the specifications provided by the manufacturer. Please refer to the Ignition System Component Testing specification charts in this section for details. There are two types of charge coils. One type has a charge coil lead connected to a powerhead ground. The other type charge coil has both leads go directly to the COl box. Both charge coil types allow for a continuity test. This checks the coil's internal resistance. On charge coils that do not have a grounded lead, the short-to-ground test must also be done • If you're in doubt about any test connections verify them using the information in the Ignition Component Testing specifications charts AND the Wiring Diagrams, found in this section. The basic test for a charge coil is continuity. This measures the actual resistance from one end of the charge coil to the other. The correct specification for each coil can be found in the Ignition System Component Testing specifications chart. 1. Adjust the meter to read resistance (ohms). 2. Connect the tester across the charge coil leads and note the reading. 3. Compare the coil reading to the specifications. If the reading is well above or below the correct value it should be checked dynamically (if output specifications are available) and/or be replaced. • Remember that temperature has an affect on resistance. Most resistance specifications are given assuming a temperature of 68•F (20°C). There are two types of charge coils. One type has one coil lead connected directly to a powerhead ground through a Black wire or a grounded bolt hole. The other end of the coil has a color-coded wire. These type coils have one lead listed as Black and the other is often a White wire with a colored tracer. The other type of charge coil is not grounded. Instead, both leads go to the COl box. Both coil leads are often White with a colored tracer. When checking either type charge coil for continuity, connect the ohmmeter to the color wires listed in the specffications. A second check must be made on charge coils that are not grounded on one end. This second check is called a short-to-ground check. Make sure that this type of coil not only has correct resistance (continuity) but also is not shorted to ground (and leaking current to ground). 4. Connect one tester lead to a coil lead. 5. Touch the other tester lead to the engine ground or the mounting point of the coil. 6. If the coil is good, the reading on the ohmmeter should be infinity. Any ohm reading other than infinity (O.L on some digital meters) indicates a bad coil. 7. Repair or replace the coil. • This second check is just as crit ical as the standard continuity check. The final, and most important check, is a dynamic cranking or running output voltage check. If specifications are provided, proceed as follows: 8. Set the meter to read volts in the proper scale (as determined by the specification range in the chart}. 9. Connect the meter to the charge coil lead(s) under the appropriate conditions. For with load specifications the circuit must be complete meaning you'll have to either back-probe the wiring harness or (if this cannot be done without damaging the connectors) use jumper wires between the disconnected ends of the harness. For without load specifications you can just disconnect the harness and probe the coil sides. 10. If the coil fails to produce sufficient voltage for specifications, doubleˇ check all connections and wire colors. Once you are certain the coil is out of spec it must be replaced. Lighting Coil + See Figures 34 and 35 The lighting coil windings really aren't usually part of the ignition system (at least they aren't when separate charge coil windings are provided to power the ignition), however it operates in the same fashion as the charge and pulser coils, and it is replaced in the same fashion, so it makes sense to cover it here. On many newer Yamaha motors the charge coil winding are incorporated into the stator (along with the lighting coil), and on a few there are no distinct charge coil windings. On these late-model motors, the entire stator assembly must be replaced if a problem is isolated to the ignition charge circuit. The lighting coil checks are the same as those for the pulser and charge coils. There are normally 2 methods used in testing lighting coils, a static resistance check and a dynamic cranking or running output voltage check. Specifications vary by year and model so significantly that it precludes trying to list them in this procedure. In addition, the method of conducting the static check will vary with the specifications that are provided. Generally speaking cranking or running tests are more accurate and more likely to show intermittent problems. Dynamic checks are done under different circumstances, with load (circuit complete) and without load (circuit incomplete), again, depending upon the specifications provided by the manufacturer. • If you're in doubt about any test connections verify them using the information in the Charging System Testing specifications charts AND the Wiring Diagrams, found in this section. The basic test for a lighting coil is continuity. This measures the actual resistance from one end of the lighting coil to the other. The correct specification for each coil can be found in the Charging System Testing specifications chart. 1. Disconnect the two wires (often, but not always, Green) between the stator and the rectifier at the rectifier. Connect the ohmmeter leads to the wires and measure the resistance. 4-16 IGNITION AND ELECTRICAL SYSTEMS 2. Compare the coil reading to the specifications. If the reading is well above or below the correct value it should be checked dynamically {if output specifications are available) and/or be replaced. • Remember that temperature has an affect on resistance. Most resistance specifications are given assuming a temperature of 68•F (2o•c). 3. If the resistance is not within specification, the battery will not hold a charge and the boat accessories which depend on this coil for power may not function properly. • Unless specifically directed by the test charts, never attempt to verify the charging circuit by operating the powerhead with the battery disconnected. In most cases, such action would force current (normally directed to charge the battery), back through the rectifier and damage the diodes in the rectifier. The final, and most important check, is a dynamic cranking or running output voltage check. If specifications are provided, proceed as follows: 4. Setthe meter to read volts in the proper scale (as determined by the specification range in the chart). 5. Connect the meter to the charge coil lead(s) under the appropriate conditions. Unless otherwise directed, protect the rectifier by taking test readings with the circuit complete. You'll have to either back-probe the wiring harness or (if this cannot be done without damaging the connectors) use jumper wires between the disconnected ends of the harness. 6. If the coil fails to produce sufficient voltage for specifications, doublecheck all connections and wire colors. Once you are certain the coil is out of spec it must be replaced. Ignition Coils + See Figures 36, 37, 38 and 39 Although the best test for an ignition coil is on a dynamic ignition coil tester, resistance checks can also be performed to help determine condition. As with other coils, remember that a static test within specification cannot absolutely rule out a problem with the ignition coil under load in dynamic conditions. There are two circuits in an ignition coil, the primary winding circuit and the secondary winding circuit. Whenever possible, both need to be checked. The tester connection procedure for a continuity check will depend on how the coil is constructed. Generally, the primary circuit is the small gauge wire or wires, while the secondary circuit contains the high tension or plug lead. When there are two primary wires running to the ignition coil, the primary circuit test is performed across both of those wire terminals (for the ignition coil). When there is only one primary wire, the circuit is checked between that wire and ground. When an ignition coil is designed to fire only one spark plug, the secondary circuit is normally either through the spark plug lead (without the resistor cap, when equipped) and ground or ground wire terminal (depending upon the primary circuit wiring). If, however, the ignition coil contains 2 spark plug leads, the secondary circuit is checked across both leads (again, without the resistor caps, if equipped). Some ignition coils have the primary and/or secondary circuits grounded on one end. On these type coils, only the continuity check is done. On ignition coils that are not grounded on one end (which have 2 wires going backto the COl unit) a short-to-ground test must also be done (a check from Fig. 38 Check the secondary circuit across Fig. 39 •..or across the 2 spark plug leads Fig. 37 •.. or across the single small lead the single spark plug lead and primary (as applicable) circuit ground (wire or grounding point) .•. and ground (as applicable) ... ..ˇ IGNITION AND ELECTRICAL SYSTEMS 4-17 the primary side of the circuit to ground in order to make sure there is no continu..y}. Regardless of the coil type, compare the resistance with the Ignition System Component Testing specification charts found in this section. • When checking the secondary side, remove the spark plug caps to make the measurement (some models, like most but not only V4 and V6 motors utilize resistor caps). When equipped with resistor caps, in some cases the cap is bad, not the coil. Bad resistor caps can be the cause of high-speed misfire. Unscrew the cap and check the resistance (usually about 5 killiˇohms, give or take a killi-ohm). Leaving the cap on during measurement could condemn an otherwise in spec ignition coil. The other method used to test ignition coils is with a Dynamic Ignition Coil Tester. Since the output side of the ignition coil has very high voltage, a regular voltmeter can not be used. While resistance reading can be valuab'le, the best tool for checking dynamic coil performance is a dynamic ignition coil tester. 1. Connectthe coil to the tester according to the manufacturer's instructions. 2. Set the spark gap according to the specifications. 3. Operate the coil tor about 5 minutes. 4. It the spark jumps the gap with the correct spark color, the coil is probably good. • If you're in doubt about any test connections verify them using the information in the Ignition Component Testing specifications charts AND the Wiring Diagrams, found in this section. R -REDG -GREEN 8 -BLACKW -WHITE 0 -ORANGEBr -BROWNW/R -WHITE/RED CIWIGŖ COIL COl Unit • See Figures 40, 41 and 42 There are potentially 3 methods of testing the CDI!TCI unit. There first method is available only on a handful of Yamahas. On a few motors, there are resistance specifications charts which allow a technician to bench test the internalcircuitry of the COl unit itself. However, these tests havefallen out of favor with Yamaha and are not included in most newer service publications, so any model that was released after 1997 or 1998 (or which underwent a significant ignition system change in thattimeframe or later) does not have a unit resistance chart. TE Probably the most common and one of the most accurate methods of testing the unit is to check the output vonage. For most motors specifications are available for CDI/TCI unit output tests. This dynamic check is the preferred method of COl unit testing, as it is more likely that faults will appear under load conditions. The test connections and specifications are provided in the Ignition System Component Testing specifications charts in this section. • One reason the resistance tests have likely fallen out of favor with Yamaha is their inability to show intermittent faults which only occur under load. The output tests are FAR more reliable for this reason and are the preferred method of CDI/TCI unit testing. Fig. 40 Visually check all ignition wiring connections prior to installing the cowling 4-18 IGNITION AND ELECTRICAL SYSTEMS Fig. 41 On some motors, the CDI cover must be removed prior to testing the COl unit The 3rd and final method of CDiffCI unit testing is probably the most important. It is a process of elimination where the remaining ignition system components are first tested and proven good. II there are no problems found anywhere else in the system components or wiring, you are usually safe replacing the CDI/TCI unit. Just be certain that you haven't overlooked another possible component or wire when condemning the unit. The accompanying charts outline the resistance testing procedures for those few motors on which they are available. The unit may remain installed on the powerhead, or it may be removed for testing. In either case, the testing procedures are identical. • No resistance testing s ecifications are available for ANY Yamahas introduced {or revised) after 1997 or 1998 {ish). Select the appropriate scale on the ohmmeter.Make contact with the Red meter lead to the leads called out in the horizontal heading. Make contact with the Black meter lead to the leads called out in the vertical list of leads. Proceed slowly and carefully in the order given. The asterisk (') denotes the meter needle should swing toward continuity {zero ohms), and then return to stay at the specified value. • As usual, remember that temperature has an affect on resistance. Most resistance are given assuming a temperature of 68°F {20°C). Also, in mind that although resistance tests may show a component to be faulty {if it tests out of specification) some problems only occur under load in dynamic conditions and a unit that tests good, may still be faulty. Fig. 42 Disconnect the leads as illustrated. The leads can be moved away from the unit but are still retained by a small block CDI Unit Test Charts + See Figures 43 thru 49 2 HP COl Unit Test Chart w -22--9.5 22--9.5 2--9 7..1J oo No continuity • Needle swings once and returns to home position Fig. 43 CDI Unit Testing Chart • 2 Hp Motors W: White B: Black Br: Brown 0: OrangeUnit: k.O • • IGNITION AND ELECTRICAL SYSTEMS 4-19 3 HP CDI Unit Test Chart Stop Charge Pul5er Ground 0 R/W G/W Br W B 0 OrangeR/W: Red/White G/W: Green/White Br Brown w WhiteB Black w wˇsr 0 G/W 23R/W 20B 40 00 co : No continuity Br 0 23 204 00 G/W R/W B 00 00 00 00 00 25 00 12 00 12 00 00 * : Needle swings once and returns to home position Fig. 44 COl Unit Testing Chart -3 Hp Motors 4-5 HP CDI Unit Test Chart :-/..ˇˇˇ . 8; 0•i / \..0 ; ˇ ) '-:'' ,, IW 'ˇ ! I • )ˇ ' I l I 8 IWtR 'etW BfW: Black/White WIG: While/GrMnW/R: While/Red 8 : Bl8ck Sr :Brown w :While Stop w Stop w Charge B< 0 WIG 18A • 27.6(LowwoOcn W1R 16 ..24(H..speed' 3.2 ..4.8 !Qnilion BtW - cnarge 0 --18,4ˇZ7.6 16 ..24 -3.2 ..4.8 -.. - WIR -- 9.6 .. -* : Needle swings once and returns to home' position Fig. 45 COl Unit Testing Chart -4-5 Hp Motors 6-8 HP CDI UNIT TESTING (2ˇStroke) /; inspection. Use analogue tester. ,A....ˇ-. • Digital tester can not be . used for this f 0 i I 0 • C.D.I. resistance values will vary from-.. ? meter to meter, especially with electronic ._'-'-digital meters. Fpr some testers, polarity Unitkll Ea11h Ignition B BtW --* --7.2 ˇ 10.8 -9.6 ..14.4 -* - Unit: kn Ignition 0 oo*oo*00oo* of leads is reversed. Unit: Kn . ..V..&..ij.. B Br G0 w W(R .: Black :Brown :Green :Orange :White :White/Red Fig. 46 COl Unit Testing Chart -6/8 Hp Motors e w 8 Br W/R w 00 00 8 00 7.5 -11 .3' 00 Br 00 63.2 -94.8 W!R 8.8 -13.2 14.4 -21.6 30.4 -45.6 0 00 00 I! 00 00 • : Needle swings once and returns to home position. "" : Discontinuity 0 00 . St'op Earth Charge Pulser Whitt Black ˇ Brown Whitt!red Stop White eo eo eo Earth Stack 9-19 1-6 eo Charge Brown ao-1eo 70-150 eo P.Jiser White/red 33-63 7--17 15-35 IQnition Orange eo eo eo eo Ignition Oflng8 eo eo * * 4-20 IGNITION AND ELECTRICAL SYSTEMS 20-30 HP (430cc & 496cc) COl Unit Test Chart w :White W!R :White/Red B : Blad' W/B :White/Black B/0 : Black/Orange Br :Brown B/W : Black/White L :Blue Stop Grour>d lgn;t;on Putser Charge W 8 BiO Btw W!R W/8 Br Stop W -40--2.0-"2.0 -3.0- Groond B S.O S.O 10..30 • 100 B!O Ignition Btw Pulser -W/B Charge Fig. 47 COl Unit Testing Chart ˇ 20/25 Hp (430cc And 496cc) Motors 40 HP (2 Cyl) COl Unit Test Chart Fig. 48 COl Unit Testing Chart • 40 Hp (2 Cyl) Motors : * ˇˇ'ˇˇ Needle swings once and ret..ms to home position. oc ..... No continuity Unit : kO The test indicated by "•" should be made with the condenser completely discharged, and therefore, the needle will not deflect again. If any charge remains in the condenser, the needle will not swing at all. IGNITION AND ELECTRICAL SYSTEMS 4-21 48/55 HP (2-Cyl) CB : Black Br : Brown 0 : Orange W :White W/R : White/Red Fig. 49 CD! Unit Testing Chart • 48/55 Hp Motors Ol Unit Test Chart Unit: k.Q CD