Yamaha C40 Manual
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Maintenance 46 4. Once a month, check the specific gravity of the electrolyte and recharge as re- quired to prolong battery life. EMU28450 Cleaning the outboard motor After use, wash the exterior of the outboard motor with fresh water. Flush the cooling system with fresh water. NOTE: For cooling system flushing instructions, see page 43. EMU28460 Checking painted surface of motor Check the motor for scratches, nicks, or flak- ing paint. Areas with damaged paint are more likely to corrode. If necessary, clean and paint the areas. A touch-up paint is avail- able from your Yamaha dealer. EMU28486 Periodic maintenance WARNING EWM01070 Be sure to turn off the engine when you perform maintenance unless otherwise specified. If you or the owner is not famil- iar with machine servicing, this work should be done by your Yamaha dealer or other qualified mechanic. Maintenance, replacement, or repair of the emission control devices and sys-tems may be performed by any marine engine repair establishment or individual. All warranty repairs, however, including those to the emission control system, must be performed by an authorized Yamaha marine dealership. A service manual is available for purchase through your Yamaha dealer for owners who have the mechanical skills, tools, and other equipment necessary to perform mainte- nance not covered by this owner’s manual. EMU28510 Replacement parts If replacement parts are necessary, use only genuine Yamaha parts or parts of the same type and of equivalent strength and materi- als. Any part of inferior quality may malfunc- tion, and the resulting loss of control could endanger the operator and passengers. Yamaha genuine parts and accessories are available from your Yamaha dealer. ZMU03223 ✩✦✯✬✤✲✲✣ ✧✩
Maintenance 47 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 Battery Inspection / charging Cooling water pas- sagesCleaning Cowling clamp Inspection Fuel filter (can be dis- assembled)Inspection / cleaning Fuel system Inspection Fuel tank (Yamaha por- table tank)Inspection / cleaning Gear oil Change Greasing points Greasing Idling speed (carbure- tor models)Inspection Power trim and tilt unit 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✩✦✯✬✤✲✲✣ ✧✪
Maintenance 48 Water pumpInspection / replace- ment Oil pump Inspection / adjustment Oil tank water drain Inspection / cleaning Spark plug(s)Cleaning / adjustment / replacement Item ActionsInitial Every 10 hours (1 month)50 hours (3 months)100 hours (6 months)200 hours (1 year) ✩✦✯✬✤✲✲✣ ✧✫
Maintenance 49 EMU28931 Greasing Yamaha marine grease (Water resistant grease) 40, 50 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 attempt to diagnose any problems yourself. Instead, take the outboard motor to a ZMU03414 ✩✦✯✬✤✲✲✣ ✧✬
Maintenance 50 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 youare 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: 40TR B7HS-10 50TR B8HS-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 51 Checkpoints Fuel system parts leakage Fuel line joint leakage Fuel line cracks or other damage Fuel connector leakage EMU28980 Inspecting fuel filter WARNING EWM00310 Gasoline is highly flammable, and its va- pors are flammable and explosive. If you have any question about properly doing this procedure, consult your Yamaha dealer. Do not perform this procedure on a hot or running engine. Allow the engine to cool. There will be fuel in the fuel filter. Keep away from sparks, cigarettes, flames or other sources of ignition. This procedure will allow some fuel to spill. Catch fuel in a rag. Wipe up anyspilled fuel immediately. The fuel filter must be reassembled carefully with the O-ring, filter cup, and hoses in place. Improper assembly or replacement could result in a fuel leak, which could result in a fire or explosion hazard. EMU29001 Cleaning fuel filter 1. Remove the nut holding the fuel filter as- sembly if equipped. 2. Unscrew the filter cup, catching any spilled fuel in a rag. 3. Remove the filter element, and wash it in solvent. Allow it to dry. Inspect the filter element and O-ring to make sure they are in good condition. Replace them if necessary. If any water is found in the fuel, the Yamaha portable fuel tank or other fuel tanks should be checked and cleaned. ZMU03126 1. Nut ZMU03127 1 ✩✦✯✬✤✲✲✣ ✤
Maintenance 52 4. Reinstall the filter element in the cup. Make sure the O-ring is in position in the cup. Firmly screw the cup onto the filter housing. 5. Attach the filter assembly to the bracket so that the fuel hoses are attached to the filter assembly. 6. Run the engine and check the filter and lines for leaks. 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 dependingon 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 42. EMU29061 Checking water in engine oil tank A translucent water drain hose is connected from the bottom of the oil tank to the filler neck. If water or foreign matter collects in this hose, consult a Yamaha dealer. EMU29112 Checking wiring and connectors Check that each grounding wire is properly secured. Check that each connector is engaged se- 1. Filter cup 2. Filter element 3. Filter housing 4. O-ring ZMU02079 1 4 2 3 1. Drain hose 2. Filler neck side 12 ZMU04989 ✩✦✯✬✤✲✲✣ ✥
Maintenance 53 curely. 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. EMU29162 Checking power trim and tilt / power tilt system WARNING EWM00430 Never get under the lower unit while it is tilted, even when the tilt support lever is locked. Severe injury could occur if the outboard motor accidentally falls. Make sure no one is under the outboard motor before performing this test. 1. Check the power trim and tilt unit / the power tilt unit for any sign of oil leaks.2. Operate each of the power trim and tilt switches / the power tilt switches on the remote control and engine bottom cowl- ing (if equipped) to check that all switch- es work. 3. Tilt the outboard motor up and check that the trim and tilt rod / the tilt rod is pushed out completely. 4. Check that the trim and tilt rod / the tilt rod is free of corrosion or other flaws. 5. Tilt the outboard motor down. Check that the trim and tilt rod / the tilt rod oper- ates smoothly. NOTE: Consult your Yamaha dealer if any operation is abnormal. 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- ZMU03240 1. Trim and tilt rod 2. Tilt support lever 12 ZMU03417 ✩✦✯✬✤✲✲✣ ✦
Maintenance 54 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. 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). ZMU01896 ZMU01897 1. Cotter pin 2. Propeller nut 3. Washer 4. Spacer ZMU03131 1 2 3 5 64 ✩✦✯✬✤✲✲✣ ✧
Maintenance 55 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. EMU29281 Changing gear oil WARNING EWM00800 Be sure the outboard motor is securely fastened to the transom or a stable 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. NOTE: If the magnetic gear oil drain screw equipped: remove all metal particles from 5. Propeller 6. Thrust washer 1. Gear oil drain screw 2. Oil level plug ZMU03133 2 1 ✩✦✯✬✤✲✲✣