Tohatsu M4C Troubleshooting
| Engine Model: Tohatsu M4C |
| Engine Type: 2-stroke 1-cylinder gasoline outboard engine |
| Total Displacement: 6.2 cu.in (102 cc) |
| Rated Engine Power: 4 Hp (2.9 kW) at 5500 rpm |
| Fuel System: Carburetor |
____________________________________________________________________________________
| Engine doesn't start or starts hard |
Fuel tank is empty - Fill it up.
Wrong grade of gasoline - Use quality fuel.
Air in fuel tank - Bleed fuel tank.
Spark plug wire is loose or disconnected - Check the spark plug wire connection, repair or replace.
Spark plug is faulty - Spark plug need to be replaced.
Fuel filter is plugged - Replace or clean fuel filter.
Carburetor is not adjusted - Check carburetor float adjustment.
Restricted fuel lines - Fuel lines need to be cleaned.
Closed or clogged fuel tank air vent - Open or service air vent.
Fuel pump pressure is low - Change or rebuild fuel pump.
Reed valve is worn or damaged - Replace reed valve.
| Engine starts but immediately stops |
Spark plug is faulty - Change spark plug.
Carburetor is faulty or clogged - Service or change carburetor.
Damaged ignition coil - Change ignition coil as required.
Fuel tank air vent restricted or closed - Open or service air vent.
Low fuel pump pressure - Change or rebuild fuel pump.
Defective ignition - Inspect ignition system and change faulty parts.
Fuel pump is defective or dirty - Service or replace fuel pump.
Carburetor problems - Carburetor diagnostics required.
Fuel lines are dirty - Fuel lines must be clean.
Fuel tank air vent restricted or closed - Open or clean air vent.
Dirty fuel filter - Replace fuel filter.
Gaskets are defective - Install new gaskets.
Engine overloaded - Reduce load.
Carburetor mixture is too lean - Use proper settings.
Ignition timing is improper - Set the ignition timing properly.
Thermostat is defective - Install new thermostat.
Water pump malfunction - Install new water pump.
Propeller pitch or diameter incorrect - Install correct propeller.
Propeller bent or damaged - Replace propeller.
Outboard engine is positioned too low or too high - Position the engine correctly.
Stale fuel - Use correct gasoline.
Engine overloaded - Reduce engine load.
Incorrectly adjusted low idle speed - Correct idle adjustment.
Dirty or damaged fuel pump - Inspect fuel pump and change as required.
Main bearings or crankshaft wear - Install new parts as as required.
Worn cylinder bore or piston rings - Change defective components.
Incorrectly adjusted or dirty carburetor - Clean or correctly adjust carburetor.
Fuel pump is dirty or defective - Clean or replace fuel pump.
Ignition system problems - Inspect ignition system and change failed components.
Gaskets are damaged - Replace gaskets.
Damaged powerhead components - Replace defective parts as required.
Propeller pitch or diameter incorrect - Install correct propeller.
Damaged or bent propeller - Have propeller repaired or replaced.
Incorrect outboard motor mounting height - Adjust the engine to correct transom height.
Incorrect trim angle - Adjust trim angle.
| Engine using too much gasoline |
Carburetor main jet is incorrectly adjusted - Adjust it correctly.
Spark plug is faulty or loose - Re-tighten or replace spark plug.
Sleeve, piston, or rings are damaged - Replace faulty parts as required.
| Engine vibrates excessively |
Damaged or bent propeller - Have propeller repaired or replaced.
Propeller shaft damaged - Replace propeller shaft.
Weeds in the propeller - Clean the propeller.
Motor mounting bolt is loose - Tighten bolt.
Steering pivot is faulty or loose Tighten correctly or replace.
____________________________________________________________________________________
| Outboard Engines Technical Specifications |
| Small Engines Technical Specifications |
| Car Engines Technical Specifications |
| Industrial Engines Technical Specifications |
