Yamaha F50TLR Troubleshooting
| Engine Model: Yamaha F50TLR |
| Engine Type: 4-stroke inline 4-cylinder OHC 8-valve gasoline outboard engine |
| Total Displacement: 57.1 cu.in (935 cc) |
| Rated Engine Power: 50 Hp (36.8 kW) at 5500 rpm |
| Fuel System: Carburetors |
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| Engine starts hard or will not start |
Fuel tank is empty - Fill it up.
Wrong grade of gasoline - Change fuel.
Fuel system clogged - Repair or replace.
Spark plug wiring connection is defective - Inspect spark plug wiring connection, change or repair.
Defective spark plug - Spark plug need to be replaced.
Clogged fuel filter - Replace fuel filter.
Carburetor components worn out - Repair or replace parts.
Clogged fuel lines - Service fuel lines.
Fuel tank air vent restricted or closed - Open or clean air vent.
Fuel pump defective - Replace or rebuild fuel pump.
Worn or improperly adjusted choke cable - Replace cable or adjust properly.
Valve clearance is wrong - Adjustment procedure required.
Valve timing is wrong - Set the valve timing correctly.
| Engine stops after starting |
Defective spark plug - Change spark plug.
Clogged or faulty carburetor - Repair or clean carburetor.
Faulty ignition coil - Ignition coil should be replaced.
Fuel tank air vent restricted or closed - Open or clean air vent.
Fuel pump malfunction - Change or rebuild fuel pump.
Damaged choke system - Change choke system components as required.
Valve clearance is not correct - Adjust valve clearance.
Valve timing is improper - Adjust valve timing as required.
Weak or damaged valve springs - Install new valve springs.
Stuck valves - Valves must be cleaned.
Ignition system problems - Test ignition and replace failed parts.
Fuel pump is dirty or defective - Clean or replace fuel pump.
Carburetor malfunction - Check and repair as required.
Fuel lines clogging - Fuel lines must be clean.
Fuel tank air vent closed or restricted - Fuel tank air vent need to be opened or cleaned.
Fuel filter is dirty - Fuel filter needs changing.
Gaskets are worn - Install new gaskets.
Clogged water intake - Need to wash or clean.
Faulty choke system - Change choke system components as required.
Engine overloaded - Reduce the load.
Carburetor fuel mixture is too lean - Use proper settings.
Incorrect ignition timing - Set the ignition timing correctly.
Thermostat is defective - Thermostat need to be replaced.
Damaged water pump - Change water pump as required.
Propeller selection improperly - Replace propeller.
Propeller bent or damaged - Replace propeller.
Outboard engine is mounted too high or too low - Position the engine correctly.
Insufficient engine oil - Add oil to the engine crankcase.
Defective oil pump - Change oil pump.
Water intake is clogged - Need to wash or clean.
Improper valve setting - Set the valves properly.
| Abnormal engine noise or knocking |
Stale or low octane fuel - Use proper gasoline.
Engine overload - Load reducing is recommended.
Wrong adjustment of low idle speed - Test and adjust.
Clogged or defective fuel pump - Check fuel pump and change if required.
Worn crankshaft or main bearings - Install new parts as as required.
Worn cylinder bore or piston rings - Change faulty components.
Carburetor is improperly adjusted or clogged - Carburetor needs to be adjusted correctly or cleaned.
Fuel pump is faulty or clogged - Test fuel pump and change if necessary.
Ignition system is defective - Inspect ignition system and change faulty parts.
Cylinder head gasket is damaged - Replace cylinder head gasket.
Worn powerhead components - Replace defective parts as required.
Valves are burned or stuck - Replace or clean valves.
Incorrect propeller selection - Check the propeller size.
Propeller bent or damaged - Replace propeller.
Incorrect outboard motor mounting height - Have motor adjusted to proper transom height.
Incorrect trim angle - Adjust trim angle correctly.
| Engine uses too much fuel |
Incorrect carburetor main jet adjustment - Adjust it correctly.
Defective or loose spark plug - Replace or tighten spark plug.
Sleeve, rings, or piston are damaged - Replace defective parts as required.
| Excessive motor vibration |
Damaged or bent propeller - Replace propeller.
Propeller shaft damaged - Have propeller shaft replaced.
Weeds clogs the propeller - Remove weeds from propeller.
Motor mounting bolt is loose - Tighten bolt.
Steering pivot is faulty or loose Tighten or replace.
Low battery voltage - Low battery charging, charge as required.
Battery discharges quickly - Service battery or change it.
Terminals are faulty or battery cables are disconnected - Connect wiring properly or install new terminals.
Starter motor is faulty - Change or repair starter.
| Trim motor runs but trim system does not move up or down |
Insufficient oil - Need to add the oil.
Pump assembly is damaged - Check pump and replace if necessary.
Leakage of manual drain valve - Valve need to be closed or changed.
Pump driveshaft or motor damaged - Replace defective component.
| Trim cannot be fully up or down |
Pump assembly is defective - Change pump as required.
Tilt ram piston ball is in wrong position - Service or repair.
Tilt ram piston O-ring is worn - Install new O-ring.
Low oil level - Fill up oil.
Lower check valve is not properly secured in port side trim ram - Install valve correctly.
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| Outboard Engines Technical Specifications |
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