Yamaha 20DWO Troubleshooting
| Engine Model: Yamaha 20DWO |
| Engine Type: 2-stroke 2-cylinder gasoline outboard engine |
| Total Displacement: 24.1 cu.in (395 cc) |
| Rated Engine Power: 20 Hp (14.7 kW) at 6000 rpm |
| Fuel System: Carburetor |
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| Engine hard starting or not starting |
Gas tank is empty - Fill it up.
Low-quality gasoline - Change gasoline.
Fuel system clogged - Repair or replace.
Defective wiring connection of spark plug - Inspect spark plug wiring connection, change or repair.
Faulty spark plug - Install new spark plug.
Fuel filter is clogged - Replace fuel filter.
Incorrect carburetor adjustment - Adjust carburetor idle mixture screw.
Clogged fuel lines - Fuel lines need to be cleaned.
Closed or restricted fuel tank air vent - Open or service air vent.
Fuel pump pressure is low - Replace or rebuild fuel pump.
Reed valve is worn or damaged - Install new reed valve.
| Engine starts but then stalls |
Spark plug is damaged - Spark plug need to be replaced.
Carburetor is defective or clogged - Clean or change carburetor.
Ignition coil is not working - Ignition coil must be replaced.
Closed or restricted fuel tank air vent - Open or service air vent.
Fuel pump pressure is low - Change or rebuild fuel pump.
Ignition system malfunction - Inspect ignition system and change faulty parts.
Clogged or defective fuel pump - Check fuel pump and change if required.
Carburetor not adjusted - Adjust according to instructions.
Dirty fuel lines - Fuel lines need to be cleaned.
Fuel tank air vent restricted or closed - Open or service air vent.
Fuel filter is plugged - Replace fuel filter.
Gaskets are defective - Replace gaskets.
Engine is running overloaded - Reduce engine load.
Carburetor fuel mixture is too lean - Use proper settings.
Ignition timing is wrong - Set the ignition timing correctly.
Faulty thermostat - Replace thermostat.
Damaged water pump - Replace water pump.
Propeller pitch or diameter incorrect - Check the propeller size.
Damaged or bent propeller - Have propeller repaired or replaced.
Outboard motor is positioned too low or too high - Mount the motor as required.
Low octane fuel - Use correct fuel.
Engine is running overloaded - Reduce the load.
Incorrectly set low idle speed - Correct the settings.
Dirty or defective fuel pump - Test fuel pump and change if necessary.
Worn crankshaft or main bearings - Crankshaft or bearings need to be replaced.
Cylinder bore or piston rings are worn - Change defective components.
Carburetor is improperly adjusted or dirty - Adjust carburetor properly or service it.
Fuel pump is defective or dirty - Check fuel pump and replace if necessary.
Ignition system failure - Test ignition and replace failed parts.
Gaskets are damaged - Replace gaskets.
Faulty powerhead components - Replace defective components as required.
Incorrect propeller selection - Install correct propeller.
Propeller bent or damaged - Replace propeller.
Incorrect outboard motor mounting height - Adjust the engine to correct transom height.
Incorrect trim angle - Adjust trim angle.
| Excessive fuel consumption |
Improper adjustment of carburetor main jet - Adjust it correctly.
Loose or defective spark plug - Spark plug need to be tightened or replaced.
Worn sleeve, rings, or piston - Replace faulty parts.
| Motor vibrates excessively |
Damaged or bent propeller - Have propeller repaired or replaced.
Propeller shaft malfunction - Replace propeller shaft.
Weeds in the propeller - Remove weeds from propeller.
Engine mounting bolt is not tightened - Tighten the bolt as required.
Steering pivot is faulty or loose Tighten or replace.
Battery capacity is low - Charge the battery.
Battery is not holding charge - Service charging system or replace battery.
Terminals are faulty or battery cables are disconnected - Connect cables properly or replace terminals.
Starter motor failure - Starter needs to be replaced.
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| Outboard Engines Technical Specifications |
| Small Engines Technical Specifications |
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| Industrial Engines Technical Specifications |
