Yamaha F50FET Troubleshooting
| Engine Model: Yamaha F50FET |
| Engine Type: 4-stroke inline 4-cylinder SOHC 8-valve gasoline outboard engine |
| Total Displacement: 60.8 cu.in (996 cc) |
| Rated Engine Power: 50 Hp (36.8 kW) at 5500 rpm |
| Fuel System: Electronic Fuel Injection (EFI) |
____________________________________________________________________________________
| Engine will not start or difficult to start |
No gasoline in tank - Add fuel.
Low-quality gasoline - Use quality gasoline.
Air in the fuel system - Air bleeding.
Damaged spark plug wiring connection - Inspect spark plug wiring connection, change or repair.
Damaged spark plug - Replace spark plug.
Fuel filter is plugged - Change fuel filter.
Vapor separator needle valve is worn or defective - Replace needle valve.
Dirt in the fuel lines - Clean fuel system lines.
Fuel tank air vent closed or restricted - Fuel tank air vent need to be opened or cleaned.
Faulty fuel feed pump - Repair or change fuel feed pump.
Throttle cable is adjusted improperly or worn - Adjust properly or replace the cable.
Valve clearance is improper - Need to adjust valve clearance.
Improper valve timing - Set the valve timing properly.
Low fuel pressure - Inspect fuel system for leaks or inspect low pressure fuel pump.
Fuel injector is dirty or worn - Clean or replace as required.
Fuel regulator malfunction - Change fuel regulator.
ECM is faulty - Change electronic control modul.
| Engine starts and stops immediately |
Spark plug is faulty - Replace spark plug.
Vapor separator needle valve is worn or defective - Replace needle valve.
Ignition coil is damaged - Ignition coil must be replaced.
Closed or restricted fuel tank air vent - Fuel tank air vent need to be opened or cleaned.
Fuel pump defective - Install new fuel pump or rebuild it.
Choke system malfunction - Change choke system components as required.
Valve clearance is not correct - Adjustment procedure required.
Valve timing is improper - Adjust valve timing as required.
Bad or broken valve springs - Valve springs need to be changed.
Valves sticking - Valves need to be cleaned.
Poor compression - Check and repair damaged parts.
Dirty fuel filter - Replace or clean fuel filter.
Fuel injector is clogged or malfunction - Replace or clean as required.
Engine oil insufficient - Fill up the oil to required level.
Oil pump is defective - Change oil pump as required.
Clogged water intake - Wash or clean as required.
Thermostat is faulty - Thermostat need to be replaced.
Water pump malfunction - Change water pump.
Defective ignition - Test ignition and replace failed parts.
Clogged or defective fuel pump - Clean or change fuel pump.
Worn or defective vapor separator needle valve - Replace needle valve.
Dirty fuel lines - Clean fuel system lines.
Fuel tank air vent restricted or closed - Open or clean air vent.
Fuel filter is plugged - Install new filter.
Intake manifold is air leaking - Replace intake manifold gasket.
Dirty water intake screen - Wash or clean as required.
Throttle link and throttle valve are wear or damaged - Change faulty parts.
Fuel injector is clogged or malfunction - Replace or clean as required.
Engine is under excessive load - Load reducing is recommended.
Fuel injector or fuel pump is clogged - Replace or clean as required.
Wrong ignition timing - Ignition timing needs to be adjusted correctly.
Defective thermostat - Thermostat need to be replaced.
Defective water pump - Install new water pump.
Improper propeller diameter or pitch - Check the propeller size.
Propeller bent or damaged - Replace propeller.
Outboard motor is positioned too low or too high - Position the engine correctly.
Engine oil insufficient - Need to add engine oil.
Oil pump malfunction - Change oil pump as required.
Water intake screen is dirty - Wash or clean as required.
Improper valve setting - Valves needs to be adjusted properly.
Low octane gasoline - Use correct gasoline.
Engine is overloaded - Load reducing is recommended.
Improperly adjusted low idle speed - Adjust as required.
Fuel pump is clogged or faulty - Test fuel pump and replace if necessary.
Crankshaft or main bearings are worn out - Have bearings or crankshaft replaced.
Worn piston rings or cylinder bore - Change faulty components.
Fuel lines are dirty - Service fuel lines.
Fuel injector is fault - Check fuel injector and replace if necessary.
Fuel pump is clogged or faulty - Check fuel pump and replace if necessary.
Ignition system problems - Check ignition system and replace faulty parts.
Blown cylinder head gasket - Replace the gasket as required.
Powerhead parts are damaged - Replace defective parts.
Burned or stuck valves - Replace or service valves.
Improper propeller diameter or pitch - Install correct propeller.
Damaged or bent propeller - Have propeller repaired or replaced.
Incorrect outboard motor mounting height - Adjust the engine to correct transom height.
Improper trim angle - Make the correct trim angle adjustment.
| Engine using too much gasoline |
Clogged or worn fuel injector - Replace or clean as required.
Defective or loose spark plug - Re-tighten or change the spark plug.
Worn piston, rings, or sleeve - Change defective components.
ECU failure - Install new ECU.
| Engine vibrates excessively |
Damaged or bent propeller - Replace propeller.
Propeller shaft malfunction - Propeller shaft needs to be replaced.
Weeds in the propeller - Remove and clean propeller.
Motor mounting bolt is loose - Tighten the bolt as required.
Loose or faulty steering pivot Tighten or replace.
Low battery capacity - Battery needs to be recharged.
Battery does not hold charge - Service charging system or replace battery.
Terminals are faulty or battery cables are disconnected - Check wiring and clean or replace terminals.
Starter motor is damaged - Repair or replace starter.
| Trim motor runs but trim system does not move up or down |
Insufficient oil - Fill up oil to required level.
Pump assembly is damaged - Check pump and change if required.
Leakage of manual release valve - Close the valve or change it.
Pump driveshaft or motor damaged - Change defective component.
| Trim does not fully up or down |
Pump assembly faulty - Replace pump.
Tilt ram piston ball is not positioned correctly - Clean or repair.
Worn tilt ram piston O-ring - Change O-ring.
Oil level is insufficient - Fill up oil.
Lower check valve is not properly secured in port side trim ram - Secure valve properly.
____________________________________________________________________________________
| Outboard Engines Technical Specifications |
| Small Engines Technical Specifications |
| Car Engines Technical Specifications |
| Industrial Engines Technical Specifications |
