Yamaha 8 Cm Owners Manual
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Maintenance 36 EMU28522 Maintenance chart Frequency of maintenance operations may be adjusted according to the operating condi- tions, but the following table gives general guidelines. Refer to the sections in this chapter for explanations of each owner-specific action. NOTE: When operating in salt water, turbid or muddy water, the engine should be flushed with clean water after each use. The “” symbol indicates the check-ups which you may carry out yourself. The “” symbol indicates work to be carried out by your Yamaha dealer. Item ActionsInitial Every 10 hours (1 month)50 hours (3 months)100 hours (6 months)200 hours (1 year) Anode(s) (external)Inspection / replace- ment Anode(s) (internal)Inspection / replace- ment Cooling water pas- sagesCleaning Cowling clamp Inspection Fuel filter (disposable)Inspection / replace- ment Fuel system Inspection Fuel tank (Yamaha por- table tank)Inspection / cleaning Gear oil Change Greasing points Greasing Idling speed (carbure- tor models)Inspection Propeller and cotter pinInspection / replace- ment Shift link / shift cable Inspection / adjustment ThermostatInspection / replace- ment Throttle link / throttle cable / throttle pick-up timingInspection / adjustment Water pumpInspection / replace- ment Spark plug(s)Cleaning / adjustment / replacement
Maintenance 37 EMU28931 Greasing Yamaha marine grease (Water resistant grease) 8 EMU28952 Cleaning and adjusting spark plug WARNING EWM00560 When removing or installing a spark plug, be careful not to damage the insulator. A damaged insulator could allow external sparks, which could lead to explosion or fire. The spark plug is an important engine com- ponent and is easy to inspect. The condition of the spark plug can indicate something about the condition of the engine. For exam- ple, if the center electrode porcelain is very white, this could indicate an intake air leak or carburetion problem in that cylinder. Do not ZMU02872
Maintenance 38 attempt to diagnose any problems yourself. Instead, take the outboard motor to a Yamaha dealer. You should periodically re- move and inspect the spark plug because heat and deposits will cause the spark plug to slowly break down and erode. If electrode erosion becomes excessive, or if carbon and other deposits are excessive, you should re- place the spark plug with another of the cor- rect type. Before fitting the spark plug, measure the electrode gap with a wire thickness gauge; adjust the gap to specification if necessary. When fitting the plug, always clean the gas- ket surface and use a new gasket. Wipe off any dirt from the threads and screw in the spark plug to the correct torque. NOTE: If a torque-wrench is not available when you are fitting a spark plug, a good estimate of the correct torque is 1/4 to 1/2 a turn past fin- ger-tight. Have the spark plug adjusted to the correct torque as soon as possible with a torque-wrench. EMU28962 Checking fuel system WARNING EWM00060 Gasoline and its vapors are highly flam- mable and explosive. Keep away from sparks, cigarettes, flames, or other sources of ignition. WARNING EWM00910 Leaking fuel can result in fire or explo- sion. Check for fuel leakage regularly. If any fuel leakage is found, the fuel system must be repaired by a qualified mechanic. Improper repairs can make the outboard unsafe to operate. Check the fuel lines for leaks, crack, or mal- function. If a problem is found, your Yamaha dealer or other qualified mechanic should re- pair it immediately. Standard spark plug: BR7HS-10 1. Spark plug gap 2. Spark plug I.D. mark (NGK) Spark plug gap: 0.9–1.0 mm (0.035–0.039 in) Spark plug torque: 25.0 Nm (18.4 ft-lb) (2.55 kgf-m)
Maintenance 39 Checkpoints Fuel system parts leakage Fuel line joint leakage Fuel line cracks or other damage Fuel connector leakage EMU28990 Checking fuel filter Check the fuel filter periodically. The fuel fil- ter is a one piece, disposable type. If foreign matter is found in the filter, replace it. For re- placement of the fuel filter, consult your Yamaha dealer. EMU29041 Inspecting idling speed WARNING EWM00451 Do not touch or remove electrical parts when starting or during operation. Keep hands, hair, and clothes away from the flywheel and other rotating parts while the engine is running. CAUTION: ECM00490 This procedure must be performed while the outboard motor is in the water. A flushing attachment or test tank can be used. A diagnostic tachometer should be used for this procedure. Results may vary depending on whether testing is conducted with the flushing attachment, in a test tank, or with the outboard motor in the water. 1. Start the engine and allow it to warm up fully in neutral until it is running smooth- ly. NOTE: Correct idling speed inspection is only possi- ble if the engine is fully warmed up. If not warmed up fully, the idle speed will measure higher than normal. If you have difficulty ver- ifying the idle speed, or the idle speed re- quires adjustment, consult a Yamaha dealer or other qualified mechanic. 2. Verify whether the idle speed is set to specification. For idle speed specifica- tions, see page 31. EMU29112 Checking wiring and connectors Check that each grounding wire is properly secured. Check that each connector is engaged se- curely. ZMU04491 ZMU02874
Maintenance 40 EMU29120 Exhaust leakage Start the engine and check that no exhaust leaks from the joints between the exhaust cover, cylinder head, and body cylinder. EMU29130 Water leakage Start the engine and check that no water leaks from the joints between the exhaust cover, cylinder head, and body cylinder. EMU29171 Checking propeller WARNING EWM00321 You could be seriously injured if the en- gine accidentally starts when you are near the propeller. Before inspecting, removing, or install- ing the propeller, remove the spark plug caps from the spark plugs. Also, place the shift control in neutral, turn the main switch to “” (off) and re- move the key, and remove the lanyard from the engine stop switch. Turn off the battery cut-off switch if your boat has one. Do not use your hand to hold the pro- peller when loosening or tightening the propeller nut. Put a wood block be- tween the anti-cavitation plate and the propeller to prevent the propeller from turning. Checkpoints Check each of the propeller blades for wear, erosion from cavitation or ventila- tion, or other damage. Check the propeller shaft for damage. Check the splines / shear pin for wear or damage. Check for fish line tangled around the pro- peller shaft. ZMU02875 ZMU02876 ZMU01897
Maintenance 41 Check the propeller shaft oil seal for dam- age. NOTE: If the shear pin equipped: it is designed to break if the propeller hits a hard underwater obstacle to help protect the propeller and drive mechanism. The propeller will then spin freely on the shaft. If this happens, the shear pin must be replaced. EMU30660 Removing the propeller EMU29194 Spline models 1. Straighten the cotter pin and pull it out using a pair of pliers. 2. Remove the propeller nut, washer, and spacer (if equipped). 3. Remove the propeller and thrust wash- er. EMU30670 Installing the Propeller EMU29231 Spline models CAUTION: ECM00340 Be sure to install the thrust washer be-fore installing the propeller, otherwise the lower case and propeller boss could be damaged. Be sure to use a new cotter pin and bend the ends over securely. Otherwise the propeller could come off during op- eration and be lost. 1. Apply Yamaha marine grease or a cor- rosion resistant grease to the propeller shaft. 2. Install the spacer (if equipped), thrust washer, and propeller on the propeller shaft. 3. Install the spacer (if equipped) and the washer. Tighten the propeller nut to the specified torque. 4. Align the propeller nut with the propeller shaft hole. Insert a new cotter pin in the hole and bend the cotter pin ends. NOTE: If the propeller nut does not align with the propeller shaft hole after tightening to the specified torque, tighten the nut further to align it with the hole. EMU29282 Changing gear oil WARNING EWM00800 Be sure the outboard motor is securely fastened to the transom or a stable 1. Cotter pin 2. Propeller nut 3. Washer 4. Propeller 5. Thrust washer ZMU02877 2 3 4 51 ZMU02063
Maintenance 42 stand. You could be severely injured if the outboard motor falls on you. Never get under the lower unit while it is tilted, even when the tilt support lever or knob is locked. Severe injury could occur if the outboard motor accidental- ly falls. 1. Tilt the outboard motor so that the gear oil drain screw is at the lowest point pos- sible. 2. Place a suitable container under the gear case. 3. Remove the gear oil drain screw and gasket. NOTE: If a magnetic gear oil drain screw is equipped, remove all metal particles from the screw before installing it. Always use new gaskets. Do not reuse the removed gaskets. 4. Remove the oil level plug and gasket to allow the oil to drain completely. CAUTION: ECM00710 Inspect the used oil after it has been drained. If the oil is milky, water is getting into the gear case which can cause geardamage. Consult a Yamaha dealer for re- pair of the lower unit seals. NOTE: For disposal of used oil, consult your Yamaha dealer. 5. With the outboard motor in a vertical po- sition, and using a flexible or pressur- ized filling device, inject the gear oil into the gear oil drain screw hole. 6. Put a new gasket on the oil level plug. When the oil begins to flow out of the oil level plug hole, insert and tighten the oil level plug. 7. Put a new gasket on the gear oil drain screw. Insert and tighten the gear oil drain screw. EMU29302 Cleaning fuel tank WARNING EWM00920 Gasoline is highly flammable, and its va- pors are flammable and explosive. If you have any question about properly doing this procedure, consult your 1. Gear oil drain screw 2. Oil level plug ZMU0287912 Recommended gear oil: Hypoid gear oil SAE#90 Gear oil quantity: 160.0 cm 3 (5.41 US oz) (5.64 Imp.oz) ZMU02880
Maintenance 43 Yamaha dealer. Keep away from sparks, cigarettes, flames, or other sources of ignition when cleaning the fuel tank. Remove the fuel tank from the boat be- fore cleaning it. Work only outdoors in an area with good ventilation. Wipe up any spilled fuel immediately. Reassemble the fuel tank carefully. Im- proper assembly can result in a fuel leak, which could result in a fire or ex- plosion hazard. Dispose of old gasoline according to lo- cal regulations. 1. Empty the fuel tank into an approved container. 2. Pour a small amount of suitable solvent into the tank. Install the cap and shake the tank. Drain the solvent completely. 3. Remove the screws holding the fuel joint assembly. Pull the assembly out of the tank. 4. Clean the filter (located on the end of the suction pipe) in a suitable cleaning sol- vent. Allow the filter to dry. 5. Replace the gasket with a new one. Re- install the fuel joint assembly and tighten the screws firmly. EMU29312 Inspecting and replacing anode(s) Yamaha outboard motors are protected fromcorrosion by sacrificial anodes. Inspect the external anodes periodically. Remove scales from the surfaces of the anodes. Consult a Yamaha dealer for replacement of external anodes. CAUTION: ECM00720 Do not paint anodes, as this would render them ineffective. NOTE: Inspect ground leads attached to external anodes on equipped models. Consult a Yamaha dealer for inspection and replace- ment of internal anodes attached to the pow- er unit. EMU29390 Checking top cowling Check the fitting of the top cowling by push- ing it with both hands. If it is loose have it re- paired by your Yamaha dealer. ZMU02881 ZMU02882
Maintenance 44 EMU29400 Coating the boat bottom A clean hull improves boat performance. The boat bottom should be kept as clean of ma- rine growth as possible. If necessary, the boat bottom can be coated with an anti-foul- ing paint approved for your area to inhibit marine growth. Do not use anti-fouling paint which includes copper or graphite. These paints can cause more rapid engine corrosion. ZMU01943
45 Trouble Recovery EMU29424 Troubleshooting A problem in the fuel, compression, or igni- tion systems can cause poor starting, loss of power, or other problems. This section de- scribes basic checks and possible remedies, and covers all Yamaha outboard motors. Therefore some items may not apply to your model. If your outboard motor requires repair, bring it to your Yamaha dealer. If the engine trouble warning indicator is flashing, consult your Yamaha dealer. Starter will not operate. Q. Is battery capacity weak or low? A. Check battery condition. Use battery of recommended capacity. Q. Are battery connections loose or corrod- ed? A. Tighten battery cables and clean battery terminals. Q. Is fuse for electric start relay or electric cir- cuit blown? A. Check for cause of electric overload and repair. Replace fuse with one of correct am- perage. Q. Are starter components faulty? A. Have serviced by a Yamaha dealer. Q. Is shift lever in gear? A. Shift to neutral. Engine will not start (starter operates). Q. Is fuel tank empty? A. Fill tank with clean, fresh fuel. Q. Is fuel contaminated or stale?A. Fill tank with clean, fresh fuel. Q. Is fuel filter clogged? A. Clean or replace filter. Q. Is starting procedure incorrect? A. See page 21. Q. Has fuel pump malfunctioned? A. Have serviced by a Yamaha dealer. Q. Are spark plug(s) fouled or of incorrect type? A. Inspect spark plug(s). Clean or replace with recommended type. Q. Are spark plug cap(s) fitted incorrectly? A. Check and re-fit cap(s). Q. Is ignition wiring damaged or poorly con- nected? A. Check wires for wear or breaks. Tighten all loose connections. Replace worn or bro- ken wires. Q. Are ignition parts faulty? A. Have serviced by a Yamaha dealer. Q. Is engine stop switch lanyard not at- tached? A. Attach lanyard. Q. Are engine inner parts damaged? A. Have serviced by a Yamaha dealer. Engine idles irregularly or stalls. Q. Are spark plug(s) fouled or of incorrect type? A. Inspect spark plug(s). Clean or replace with recommended type.