Yamaha 50 HETOL Troubleshooting
| Engine Model: Yamaha 50HETOL |
| Engine Type: 2-stroke inline 3-cylinder gasoline outboard engine |
| Total Displacement: 42.6 cu.in (698 cc) |
| Rated Engine Power: 50 Hp (36.8 kW) at 5000 rpm |
| Fuel System: Carburetor |
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| Engine will not start or hard to start |
No gasoline in tank - Fill gasoline up.
Wrong grade of gasoline - Use correct gasoline grade.
Water or air in fuel system - Remove air or water from system.
Damaged spark plug wiring connection - Check spark plug wiring connection, repair or change.
Faulty spark plug - Change spark plug.
Fuel filter is clogged - Install new filter.
Carburetor is clogged - Clean the carburetor.
Clogged fuel lines - Fuel lines need to be cleaned.
Fuel tank air vent restricted or closed - Open or service air vent.
Lack of fuel pump pressure - Replace or repair fuel pump.
Reed valve is defective or worn - Replace reed valve as required.
| Engine stalls after starting |
Spark plug is faulty - Install new spark plug.
Clogged or faulty carburetor - Clean or change carburetor.
Defective ignition coil - Ignition coil should be replaced.
Closed or restricted fuel tank air vent - Open or service air vent.
Low fuel pump pressure - Install new fuel pump or rebuild it.
Defective ignition - Check ignition and replace faulty components.
Clogged or defective fuel pump - Check fuel pump and change if required.
Carburetor is clogged - Clean the carburetor.
Fuel lines are dirty - Clean fuel system lines.
Fuel tank air vent restricted or closed - Open or service air vent.
Fuel filter is clogged - Replace or clean fuel filter.
Gaskets are defective - Replace gaskets.
Engine overloaded - Reduce engine load.
Carburetor fuel mixture is too lean - Adjust carburetor correctly.
Improper ignition timing - Ignition timing needs to be adjusted correctly.
Defective thermostat - Install new thermostat.
Water pump failure - Change water pump as required.
Propeller selection improperly - Install correct propeller.
Propeller bent or damaged - Have propeller repaired or replaced.
Outboard engine is positioned too low or too high - Mount the motor as required.
Stale fuel - Use correct gasoline.
Excessive engine load - Load reducing is recommended.
Low idle speed set incorrectly - Correct idle adjustment.
Clogged or defective fuel pump - Check fuel pump and replace if necessary.
Crankshaft or main bearings wear - Replace crankshaft or bearings.
Damaged cylinder bore or piston rings - Change faulty parts.
Clogged or incorrectly adjusted carburetor - Adjust the carburetor properly or clean it.
Fuel pump is dirty or defective - Service or replace fuel pump.
Defective ignition - Check ignition and replace faulty components.
Gaskets are damaged - Install new gaskets.
Worn powerhead components - Defective components need to be replaced.
Propeller pitch or diameter incorrect - Install correct propeller.
Propeller bent or damaged - Replace propeller.
Engine mounted at wrong transom height - Check the outboard motor mounting height.
Improper trim angle - Adjust trim angle correctly.
| Engine uses too much fuel |
Carburetor main jet adjustment is improper - Adjust it properly.
Defective or loose spark plug - Re-tighten or replace spark plug.
Sleeve, rings, or piston are damaged - Change defective components.
| Excessive engine vibration |
Damaged or bent propeller - Have propeller repaired or replaced.
Propeller shaft damaged - Propeller shaft needs to be replaced.
Weeds in the propeller - Clean the propeller.
Engine mounting bolt is not tightened - Tighten bolt.
Loose or faulty steering pivot Tighten or replace.
Low battery capacity - Low battery charging, charge as required.
Battery is draining quickly - Service charging system or change battery.
Wires are disconnected or battery terminals are corroded - Check battery wires and service or replace terminals.
Defective starter motor - Starter should be changed.
| Trim motor runs but trim system does not move up or down |
Lack of oil - Check and refill oil.
Defective pump assembly - Check pump and change if required.
Manual shut-off valve leaks - Close the valve fully or replace it.
Faulty pump driveshaft or motor - Replace defective component.
| Trim does not fully up or down |
Defective pump assembly - Change pump as required.
Tilt ram piston ball is in wrong position - Clean or repair.
Tilt ram piston O-ring damaged - Replace O-ring.
Oil level is insufficient - Fill up oil to required level.
Lower check valve not seating in port side trim ram - Secure valve properly.
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| Outboard Engines Technical Specifications |
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