Yamaha E25BMH Troubleshooting
| Engine Model: Yamaha E25BMH |
| Engine Type: 2-stroke 2-cylinder gasoline outboard engine |
| Total Displacement: 30.2 cu.in (496 cc) |
| Rated Engine Power: 25 Hp (18.4 kW) at 5500 rpm |
| Fuel System: Carburetor |
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| Engine starts up hard or will not start |
Empty gas tank - Add gasoline.
Incorrect fuel grade - Change fuel.
There is air in the fuel system - Bleed the system.
Spark plug wire connection are damaged - Inspect spark plug wiring connection, change or repair.
Spark plug is defective - Replace spark plug.
Clogged fuel filter - Change fuel filter.
Carburetor is not adjusted - Check carburetor float adjustment.
Restricted fuel lines - Fuel lines must be clean.
Fuel tank air vent clogged or closed - Fuel tank air vent need to be opened or cleaned.
Lack of fuel pump pressure - Replace or repair fuel pump.
Damaged or worn fuel reed valve - Install new reed valve.
| Engine starts but stops suddenly |
Spark plug is defective - Replace spark plug.
Faulty or dirty carburetor - Service or repair carburetor.
Damaged ignition coil - Install a new ignition coil.
Fuel tank air vent closed or restricted - Open or clean air vent.
Low fuel pump pressure - Replace or rebuild fuel pump.
| Engine runs intermittently |
Ignition system problems - Inspect ignition system and change failed components.
Fuel pump is damaged or dirty - Check fuel pump and replace if necessary.
Problems with carburetor adjustment - Adjust as required.
Dirty fuel lines - Clean fuel system lines.
Fuel tank air vent closed or restricted - Open or clean air vent.
Fuel filter is dirty - Replace or clean fuel filter.
Gaskets are defective - Change gaskets.
Excessive engine load - Load reducing is recommended.
Carburetor is running lean - Use proper settings.
Wrong ignition timing - Ignition timing needs to be set properly.
Defective thermostat - Change thermostat as required.
Damaged water pump - Replace water pump.
Propeller pitch or diameter incorrect - Install correct propeller.
Damaged or bent propeller - Replace propeller.
Outboard motor is mounted too high or too low - Position the engine correctly.
Stale or low octane fuel - Use correct fuel.
Engine overloaded - Reduce engine load.
Incorrect low idle setting - Adjust idle speed.
Dirty or damaged fuel pump - Service or change fuel pump.
Main bearings or crankshaft failure - Worn parts replacement required.
Worn cylinder bore or piston rings - Change faulty components.
Carburetor is dirty or improperly adjusted - Adjust the carburetor properly or clean it.
Fuel pump is damaged or dirty - Test fuel pump and replace if necessary.
Ignition system problems - Check ignition system and replace faulty parts.
Damaged gaskets - Install new gaskets.
Powerhead components are damaged - Defective components need to be replaced.
Propeller selection improperly - Replace propeller.
Propeller bent or damaged - Have propeller repaired or replaced.
Outboard engine mounting height improperly - Check the outboard engine mounting height.
Incorrect trim angle - Make the correct trim angle adjustment.
Carburetor main jet adjustment is improper - Adjust the carburetor main jet correctly.
Loose or faulty spark plug - Re-tighten or replace spark plug.
Worn sleeve, rings, or piston - Replace defective parts.
| Excessive engine vibration |
Damaged or bent propeller - Replace propeller.
Damaged propeller shaft - Replace propeller shaft.
Weeds in the propeller - Remove weeds from propeller.
Motor mounting bolt is loose - Tighten the bolt as required.
Steering pivot is loose or damaged Tighten or replace.
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| Outboard Engines Technical Specifications |
| Small Engines Technical Specifications |
| Car Engines Technical Specifications |
| Industrial Engines Technical Specifications |
