Yamaha Jet Drive Operation & Service Manual Jet Drive Operation & Service Manual - Four Stroke EFI Models

Operation and Service Manual Four-Stroke JET DRIVE

Four-Stroke Jet Drive Operation and Service Manual ©2002 by Yamaha Motor Corporation, U.S.A. September 2002 All rights reserved. Any reprinting or unauthorized use without written permission of Yamaha Motor Corporation, U.S.A. is expressly prohibited. Printed in U.S.A. Specifications, features and options are subject to change without notice. 02-467

TABLE OF CONTENTS INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 FEATURES AND ADVANTAGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 LOCATION OF MAIN COMPONENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 MODEL IDENTIFICATION AND SERIAL NUMBERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 ENGINE MOUNTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 MOUNTING HEIGHT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 TEST RUNNING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 TRANSOM ELEVATORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 ANTI-CAVITATION PLATES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 OPERATING INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 SHIFTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 REMOTE CONTROL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 STEERING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 SHALLOW WATER OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 INTAKE BLOCKAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 MOORING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 THROTTLE USE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 TILT AND TRIM USE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 MAINTENANCE, LUBRICATION, AND STORAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 BEARING LUBRICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 IMPELLER CLEARANCE SETTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 LINKAGE ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 SALT WATER OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 STORAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 SHIFT CAM ASSEMBLY WITH NEUTRAL ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 NEUTRAL ADJUSTMENT OF ALL MODELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 TRIM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 IDLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 PERFORMANCE TIPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 OVERHAUL PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 F40MJH & F40EJR (F40) 4-STROKE 3-CYLINDER PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 ASSEMBLY INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 TILLER STEERING SHIFT CABLE PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 TILLER STEERING SHIFT CABLE ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 F60 4-STROKE 4-CYLINDER PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 ASSEMBLY INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 TILLER STEERING SHIFT CABLE PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 TILLER STEERING SHIFT CABLE ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 F90 4-STROKE 4-CYLINDER PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 ASSEMBLY INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

TILLER STEERING SHIFT CABLE PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 TILLER STEERING SHIFT CABLE ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 F115 4-STROKE 4-CYLINDER PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 ASSEMBLY INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 LIMITED WARRANTY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 TILLER HANDLE TEMPLATES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

1 INTRODUCTION This Four-Stroke Jet Drive Operation and Service Manual is designed to be used in conjunction with your Yamaha Outboard Motor Owner’s and Service Manuals. It contains operating instructions as well as service and maintenance information that applies specifically to Yamaha Jet Drives. Refer to your Outboard Owner’s and Service Manuals regarding general operating and service information. The related Outboard Owner’s and Service Manuals refer to horsepower rating for Yamaha’s propeller-driven models. The actual performance output of Yamaha’s Jet Drive models cannot be pos- itively rated because the output varies with type of hull, load, forward speed, and the angle of planing achieved. Generally, the industry standard for determining the performance level of a jet- driven outboard is that its output is approximately 70% of that of a propeller-driven unit with the same powerhead. This Operation and Service Manual covers several Yamaha Jet Drive models. Where there are model-year differences, references are made to applicable models. In addition, references are made throughout the manual to the model designation (which includes the engine’s prop-shaft model horsepower) or to the engine’s configuration. The following chart explains the corresponding des- ignations: 4-Stroke Read both this manual and your Outboard Motor manual before attempting to put your Yamaha Jet Drive Outboard Motor into service. You should be familiar with all the control positions, and know where each control is set during operation. Engine Horsepower Jet Drive Model Model Designation Engine Configuration Designation F40 3-cylinder 30 F60 4-cylinder 40 F90 4-cylinder 65 F115 4-cylinder 80

FEATURES AND ADVANTAGES Your Yamaha Jet Drive Outboard Motor was specifically designed to allow boating in locations where a propeller-driven craft is unable to operate, such as in ankle-deep water, white- water rapids, over sand bars, shoals, etc. Because there is no propeller housing extend- ing below the hull, your Yamaha Jet Drive allows passage over obstructions that would damage a regular outboard. Shore landings are made easier because you don’t have to tilt the motor. A “fish’s eye view” gives a further comparison of the difference between a propeller-driven boat and a jet drive. Your Yamaha Jet Drive’s simple design offers reliable operation with minimal moving parts. Water is drawn into the unit through the intake grille by an impeller, driven directly by the engine drive shaft. The water is then forced at high pressure through an outlet nozzle that is directed away from the stern of the boat. This action creates an opposite force, similar to that of a jet engine, and drives the boat forward. When the boat reaches planing speed, the jet drive discharges water freely into the air and only the intake grille touches the water. To obtain reverse, a gate is swung into position over the outlet, directing the pressure stream in the opposite direction, thus creating a reverse thrust to propel the boat backwards. Conventional controls are used for throttle, shifting, and steering. LOCATION OF MAIN COMPONENTS 2 JET DRIVE JET DRIVE CASING REVERSE GATE IMPELLER (INTERNAL) INTAKE ASSEMBLY EXHAUST TUBE GREASE NIPPLE VENT HOSE WATER INTAKE GRILLE MOTOR ADAPTER PLATE CAM GATE CONTROL CABLE OR ROD CONTROL CABLE ANCHOR BRACKET

3 MODEL IDENTIFICATION AND SERIAL NUMBERS OUTBOARD IDENTIFICATION See your Yamaha Outboard Motor Owner’s Manual for outboard and motor identification number locations. JET DRIVE IDENTIFICATION The Jet Drive Model Letter is stamped on the rear, port-side casing. The Jet Drive Serial Number is stamped on the starboard side of the casing. NOTE: The outboard motor and jet-drive unit model and serial numbers are important when you need to have service performed or place an order for parts. For easy reference, please record these numbers on the inside front cover of this manual, and also on the inside front cover of your Yamaha Outboard Motor Owner’s Manual. APPLICATION AND SIZING HULL SELECTION Best performance is obtained by selecting a light, shallow-draft hull, with a relatively flat (5° angle, or less), wide bottom. Vee or Multi-Vee hulls are not recommended (additional drag would be placed on the Jet Drive’s water intake housing) because of their greater tendency to produce cavitation. Aluminum boats are pre- ferred because of their light weight and dura- bility. These boats typically have optimum hull shapes, too. As a rule, the bottom width for your jet drive should be at least 48”, and the centerline length at least 13’. NOTE: Transom height is especially critical for jet-driven outboards, which are usually mounted 6” to 7” higher than propeller-driven outboards; therefore, it is advisable to use a full transom with your Jet Drive. MOTOR SELECTION MOTOR SIZING A boat operating at slow speed requires con- siderably more depth than one that is planing on the surface of the water. It is important, therefore, to use sufficient horsepower, and to not overload your boat beyond its ability to plane. The accompanying graph is based on experi- ence obtained with sled-type boats, using an outboard-style jet. Gross weights shown include the motor, hull, fuel, passengers, and all gear. For a given horsepower, loading beyond the listed limits will obviously give reduced performance. Conversely, slight overpowering, based upon anticipated load, will result in quicker planing, reduced throttle settings for a given speed, and, subsequently, increased efficiency of operation. NOTE: The performance output levels of jet- driven outboards do not reflect true performance compared to propeller-driven outboards of the same powerhead horsepower. The Jet- Driven model is usually figured to have an output level equal to 70% of the propeller-driven model. Keep in mind that boat loading, weight, and hull configuration can significantly affect the performance of your Jet Drive outboard.

4 ENGINE MOUNTING MOUNTING HEIGHT Your Yamaha Jet Drive must be mounted 6” to 7” higher on the transom than propeller-driven outboards. Therefore, optimum mounting for 15” shafts is on a 20” transom; and for 20” shafts, a 25” transom. The positioning of motor height is important and must be done carefully. One-quarter inch above the optimum location will allow air to enter the pump and will result in cavitation and power loss. Too low a setting will result in unnecessary drag, water spray, and reduction in speed. The initial height setting is accomplished by placing a yardstick or other straightedge against the boat bottom (not the keel). The top of the leading edge of the water intake is adjusted to line up with the top edge of the straightedge. TEST RUNNING When starting your motor for the first time, make sure water comes out the small hole at the rear, starboard side of the motor, just below the powerhead. If no water exits with- in a short period of time, shut off the motor and consult your dealer. After making the initial motor-height setting, it is time to test-run the boat. If cavitation occurs (air enters the pump, which causes loss of thrust and motor overrevving), then you must lower the engine 1/4” at a time until smooth operation is obtained. If smooth operation is obtained with the initial setting, you should raise the motor in 1/4” steps until cavitation does occur. Then lower the motor 1/4”, and mark and lock that location. This height setting will never need to be changed, regardless of the load being carried. Slight cavitation on sharp turns or in rough water is acceptable, but excessive cavitation is harmful to both motor and pump, and should be avoided. The motor tilt pin should be set so the engine is in a vertical position when the boat is planing. If the boat rides bow-high, or tends to be stern heavy, tilt the motor down one step. This will point the jet stream lower, giving added lift to the stern. NOTE: If the tilt angle is changed, then the motor height must be rechecked. TRANSOM ELEVATORS In some applications, an elevated transom may be required for proper motor height. When using a bolted-on bracket, set the intake height 1/2” below the bottom of the boat in order to obtain the widest range of adjustability, as shown. 1. Glue two pieces of 3/4” exterior plywood together, using waterproof glue. Clamp or nail. 2. Bolt to transom at height shown. Use zinc- plated hardware, with flat washers on both sides. CAUTION: CAUTION: F40 & F50 MODELS F80 & F115 MODELS

5 3. Make two diagonal braces from 1/2” elec- trical conduit. Flatten each end in a vise, and drill 1/4” holes in them. Determine the position and angle of the forward bend. Attach the braces to the boat in a solid location, such as to the seats or gunwales. Avoid attachment to flexible aluminum pan- els. ANTI-CAVITATION PLATES To reduce spray, or to further reduce cavitation in rough water, a 1/32”-thick metal plate can be installed to block the entrance of air into the water in front of the jet pump’s intake scoop. Installation of this plate will also allow a slight- ly higher motor-mounting point (which, of course, will reduce drag). The position for proper mounting is shown in the first part of the accompanying illustration. An alternate mounting position for the plate (with the plate attached to a keel or wedge), for use in “white water,” is shown in the second and third parts of the illustration. The third part shows the width of the plate, as well as the width of the drop-bottom wedge that positions the intake in more solid water. This installation, however, reduces shallow-water capabilities and should be used only when necessary. After one of these procedures is undertak- en, the motor height and tilt settings should be checked, and reset as necessary, to avoid excessive cavitation that could lead to impeller damage. NOTE: Either of the above modifications should utilize only marine-grade woods; sili- con-base, waterproofing sealing compounds (between components and around screws); and marine-grade paints. Remember, once you adopt one of these modifications, if removed or changed, damage may result to your hull if precautions are not taken to fill and/or waterproof any holes. CAUTION:

6 OPERATING INSTRUCTIONS SHIFTING The impeller is always engaged and pro- duces a certain amount of thrust while the motor is running. “Neutral” is achieved when the reverse gate is in a middle position that balances forward and reverse thrust. Since the Neutral position on the shift control may not precisely balance the thrust, be sure to secure the boat to the dock or beach the bow of the boat during cold starts to avoid the possibility of being thrown off balance as the motor starts. Except for low-speed maneuvering, do not use the reverse gate to slow or stop the boat; this will cause the motor to kick up and out of the water, similar to hitting a submerged object in a propeller-driven craft. REMOTE CONTROL When using a remote control with a fast-idle feature, the throttle can be advanced with the transmission in Neutral for cold engine starts. When using this fast-idle starting feature, the shift cam may not immediately engage when the throttle is returned to the Neutral position due to water pressure action on the reverse gate. After the motor has warmed up for 30 seconds or so, stop the motor, move the throttle lever through the shifting mode until the cam has engaged, place it in Neutral, and restart the motor. Subsequent warm starts in Neutral will not require this operation. STEERING Experiment with steering your boat in an open area before attempting downstream river running. Remember when running downstream, your speed relative to the shore is the boat’s speed added to the speed of the river. You may find quick response to the helm, but due to its relatively flat-bottomed hull and lack of skeg, your boat will tend to skid in turns. You must start your turns early and use sufficient power to maintain steering control. If you attempt too tight a turn, at too high a speed, your boat could spin out, or even roll over. Running upstream is easier, as the river speed is subtracted from the boat’s speed, and the shore doesn’t go by as fast. You can throttle back and maneuver your way through tight areas with good control. At narrow and poten- tially rough or dangerous passages, you should stop and study the layout. Look downstream so you will recognize it on the return trip. Once through a bad spot, you may wish to run down and travel back up the same stretch to memorize the course you find to be the best. If you are not sure of a tight area on a downstream run, it is better to drift through on the oars with the motor tipped up, or work the boat through on a rope. SHALLOW WATER OPERATION The life of both impeller and water intake housing can be greatly increased by avoiding the intake of sand and gravel. Intake suction, act- ing on the bottom, will cause your jet drive to work like a dredge when the intake comes with- in 2 or 3 inches of the bottom. It is best to shut off the motor and drift up to the shore when landing, and to shove off with an oar when leaving. You can idle through areas less than 1- foot deep, but there should be more than 1 foot of water under the boat when opening the throttle for cruising or planing. Once planing, boat speed will prevent sucking in gravel. While great suction exists at the water intake, your boat passes over the bottom so quickly that before rocks, sand, and debris have time to lift, the boat is past the disturbed area. While boating in particularly shallow areas, remember that running on a full plane will make the boat ride higher in the water. This can allow you to travel through areas that might be impossible to traverse at slow speeds. Be sure you know the type of river bottom before attempting this, however, in case the boat hits bottom or runs aground. You should attempt planing only in areas where the bottom is sand or gravel. If you hit bottom where there are large underwater obstacles or sharp rocks, you may damage the boat and motor. If you do run aground, shut the motor off immediately and drag the boat to deeper water. Occasionally, when running aground, a small rock may lodge between the impeller and WARNING  WARNING 

Yamaha Jet Drive Operation & Service Manual Jet Drive Operation & Service Manual - Four Stroke EFI Models

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