Yamaha 15C Troubleshooting
| Engine Model: Yamaha 15C |
| Engine Type: 2-stroke 2-cylinder gasoline outboard engine |
| Total Displacement: 15 cu.in (246 cc) |
| Rated Engine Power: 15 Hp (11 kW) at 5500 rpm |
| Fuel System: Carburetor |
____________________________________________________________________________________
| Engine will not start or difficult to start |
No gasoline in tank - Fill fuel up.
Wrong fuel grade - Change fuel.
Dirty fuel system - Check and clean.
Damaged spark plug wiring connection - Inspect spark plug wiring connection, change or repair.
Spark plug is damaged - Spark plug need to be replaced.
Clogged fuel filter - Change fuel filter.
Carburetor is not adjusted - Check carburetor float adjustment.
Fuel lines clogging - Service fuel lines.
Fuel tank air vent restricted or closed - Open or clean air vent.
Fuel pump pressure is low - Install new pump or repair it.
Reed valve is worn or damaged - Replace reed valve as required.
| Engine starts and then stalls |
Defective spark plug - Spark plug need to be replaced.
Defective or clogged carburetor - Replace or service carburetor.
Ignition coil is defective - Ignition coil should be replaced.
Fuel tank air vent clogged or closed - Open or clean air vent.
Fuel pump pressure is low - Repair or change fuel pump.
| Engine runs intermittently |
Ignition failure - Inspect ignition system and change failed components.
Dirty or defective fuel pump - Check fuel pump and replace if necessary.
Carburetor incorrectly set - Set carb correctly.
Fuel lines are dirty - Fuel lines need to be cleaned.
Fuel tank air vent restricted or closed - Open or clean air vent.
Plugged fuel filter - Fuel filter needs to be replaced.
Damaged gaskets - Install new gaskets.
Engine overload - Reduce the load.
Carburetor fuel mixture is too lean - Use proper settings.
Ignition timing is incorrect - Set the ignition timing correctly.
Defective thermostat - Thermostat need to be replaced.
Defective water pump - Change water pump.
Incorrect propeller selection - Check the propeller size.
Damaged or bent propeller - Replace propeller.
Outboard motor is positioned too low or too high - Mount the motor as required.
| Abnormal engine knocking or noise |
Stale fuel - Use correct fuel.
Engine overloaded - Load reducing is recommended.
Improperly adjusted low idle speed - Test and adjust.
Clogged or defective fuel pump - Clean or install new fuel pump.
Main bearings or crankshaft failure - Need to install new components.
Cylinder bore or piston rings are damaged - Replace faulty components.
Carburetor is clogged or incorrectly adjusted - Adjust the carburetor properly or clean it.
Dirty or defective fuel pump - Check fuel pump and replace if necessary.
Ignition system is defective - Test ignition and replace failed parts.
Gaskets are defective - Install new gaskets.
Damaged powerhead parts - Replace defective parts.
Propeller selection improperly - Install correct propeller.
Damaged or bent propeller - Have propeller repaired or replaced.
Engine mounted at wrong transom height - Adjust the engine to correct transom height.
Improper trim angle - Adjust trim angle correctly.
| Engine uses too much fuel |
Improper adjustment of carburetor main jet - Adjust the carburetor main jet properly.
Spark plug is faulty or loose - Change or re-tighten spark plug.
Sleeve, rings, or piston are damaged - Change defective parts.
| Excessive engine vibration |
Damaged or bent propeller - Replace propeller.
Propeller shaft malfunction - Replace propeller shaft.
Weeds clogs the propeller - Remove and clean propeller.
Engine mounting bolt is not tightened - Tighten bolt.
Steering pivot is loose or damaged Tighten or replace.
____________________________________________________________________________________
| Outboard Engines Technical Specifications |
| Small Engines Technical Specifications |
| Car Engines Technical Specifications |
| Industrial Engines Technical Specifications |
