Tohatsu MFS6C Troubleshooting
| Engine Model: Tohatsu MFS6C |
| Engine Type: 4-stroke 1-cylinder OHV gasoline outboard engine |
| Total Displacement: 7.5 cu.in (123 cc) |
| Rated Engine Power: 6 Hp (4.4 kW) at 6000 rpm |
| Fuel System: Carburetor |
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| Engine difficult to start or won't start |
Gas tank is empty - Add gasoline.
Wrong grade of gasoline - Change fuel.
Water or air in fuel system - Remove air or water from system.
Loose or disconnected spark plug wire - Inspect the spark plug wire connection, replace or repair.
Faulty spark plug - Install new spark plug.
Clogged fuel filter - Fuel filter needs changing.
Carburetor malfunction - Check and repair as required.
Fuel lines are dirty - Fuel lines need to be cleaned.
Closed or restricted fuel tank air vent - Fuel tank air vent need to be opened or cleaned.
Fuel pump defective - Install new pump or repair it.
Throttle cable is damaged or adjusted incorrectly - Adjust properly or change the cable.
Improper valve clearance - Check and adjust.
Valve timing is incorrect - Set the valve timing correctly.
| Engine starts and stalls suddenly |
Spark plug is faulty - Change spark plug.
Carburetor is clogged or faulty - Repair or clean carburetor.
Ignition coil is defective - Ignition coil should be replaced.
Fuel tank air vent restricted or closed - Open or clean air vent.
Fuel pump defective - Install new pump or repair it.
Damaged choke system - Change choke system components as required.
Valve clearance is not correct - Adjust valve clearance according to specifications.
Valve timing is improper - Set the valve timing properly.
Valve springs are broken or bad - Change valve springs.
Valves sticking - Clean the valves.
Defective ignition system - Check ignition and replace faulty components.
Fuel pump is dirty or defective - Check fuel pump and change if required.
Carburetor components worn out - Repair or replace parts.
Clogged fuel lines - Clean fuel lines.
Closed or clogged fuel tank air vent - Fuel tank air vent need to be opened or cleaned.
Dirty fuel filter - Change fuel filter.
Worn gaskets - Install new gaskets.
Water intake screen is dirty - Need to clean or wash.
Faulty choke system - Inspect and replace choke system components.
Excessive engine load - Reduce engine load.
Too lean carburetor mixture - Adjust carburetor properly.
Incorrect ignition timing - Set the ignition timing properly.
Faulty thermostat - Thermostat need to be replaced.
Water pump failure - Change water pump.
Improper propeller diameter or pitch - Install correct propeller.
Damaged or bent propeller - Have propeller repaired or replaced.
Outboard motor is mounted too high or too low - Position the engine correctly.
Lack of engine oil - Fill up the oil to required level.
Oil pump failure - Oil pump need to be replaced.
Water intake screen is dirty - Need to wash or clean.
Valve setting is incorrect - Valves needs to be set correctly.
Stale gasoline - Use correct gasoline.
Engine overload - Reduce engine load.
Low idle speed adjustment is incorrect - Adjust idle speed.
Dirty or damaged fuel pump - Clean or install new fuel pump.
Worn crankshaft or main bearings - Worn parts replacement required.
Worn piston rings or cylinder bore - Change defective parts.
| Engine power is insufficient |
Carburetor is improperly adjusted or clogged - Clean or correctly adjust carburetor.
Clogged or damaged fuel pump - Check fuel pump and replace if necessary.
Ignition system failure - Inspect ignition system and change failed components.
Cylinder head gasket is damaged - Replace the gasket as required.
Worn powerhead components - Change defective parts.
Stuck or burned valves - Service or replace valves.
Improper propeller diameter or pitch - Check the propeller size.
Damaged or bent propeller - Have propeller repaired or replaced.
Outboard engine mounting height improperly - Adjust the engine to correct transom height.
Trim angle is incorrect - Adjust trim angle correctly.
| Engine uses too much fuel |
Carburetor main jet adjustment is incorrect - Adjust main jet as required.
Spark plug is loose or defective - Tighten or replace spark plug.
Piston, sleeve, or rings are damaged - Change faulty parts.
| Excessive motor vibration |
Damaged or improper size of propeller - Replace propeller.
Propeller shaft malfunction - Replace propeller shaft.
Weeds clogs the propeller - Clean the propeller.
Engine mounting bolt is not tightened - Tighten the bolt as required.
Steering pivot is faulty or loose Tighten correctly or replace.
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| Outboard Engines Technical Specifications |
| Small Engines Technical Specifications |
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| Industrial Engines Technical Specifications |
