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| Home / Outboard Engines / Suzuki Engines / Suzuki DF9.9B |
Suzuki DF9.9B Troubleshooting
The Suzuki DF9.9B is a 4-stroke 2-cylinder OHC (overhead cam) gasoline outboard engine with a rated power of 9.9 hp (7.3 kW) at 4700-5700 rpm. The engine cylinder bore is 2.38" (60.4 mm) and piston stroke is 2.24" (57 mm). A 20.1 cubic inches (327 cc) outboard motor has a multi-point sequential electronic fuel injection, integral fuel pump type, pressure lubrication system, starting system with recoil or electric starter, Digital CDI ignition, manual or power tilt, and tiller handle or remote control steering. The fuel tank capacity is 3.2 gal (12 liters). The propeller is made of aluminum and it has three blades.
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| Engine won't start or difficult to start |
Empty fuel tank - Add fuel.
Low-quality gasoline - Use correct gasoline grade.
Air in the fuel lines - Bleed the fuel lines.
Disconnected or loose spark plug wire - Check spark plug wiring connection, repair or change.
Faulty spark plug - Spark plug need to be replaced.
Dirty fuel filter - Fuel filter needs to be replaced.
Worn or defective vapor separator needle valve - Change vapor separator needle valve.
Restricted fuel lines - Clean fuel system lines.
Closed or clogged fuel tank air vent - Open or service air vent.
Defective fuel feed pump - Replace or rebuild fuel feed pump.
Improperly adjusted or worn throttle cable - Adjust properly or replace the cable.
Valve clearance is incorrect - Adjust valve clearance according to specifications.
Improper valve timing - Set the valve timing correctly.
Fuel pressure is low - Check low pressure fuel pump or check system for fuel leaks.
Fuel injector is damaged or dirty - Replace or clean if necessary.
Fuel regulator malfunction - Change fuel regulator.
ECM failure - Install new ECM.
| Engine starts and immediately shuts off |
Faulty spark plug - Spark plug need to be replaced.
Vapor separator needle valve is worn or defective - Replace needle valve.
Ignition coil is defective - Replace ignition coil as necessary.
Fuel tank air vent closed or restricted - Open or service air vent.
Defective fuel pump - Repair or change fuel pump.
Faulty choke system - Change choke system components as required.
Valve clearance is not correct - Check and adjust.
Valve timing is wrong - Adjust valve timing as required.
Broken or bad valve springs - Install new valve springs.
Valves are stuck - Valves need to be cleaned.
Bad cylinder compression - Check and change damaged parts.
Plugged fuel filter - Install new filter.
Fuel injector is dirty or worn - Clean or install new injector.
Low engine oil level - Add oil to the engine crankcase.
Defective oil pump - Change oil pump.
Clogged water intake - Wash or clean as required.
Thermostat failure - Change thermostat as required.
Water pump is defective - Install new water pump.
| Engine runs unevenly |
Ignition system failure - Inspect ignition system and change faulty parts.
Fuel pump is damaged or dirty - Check fuel pump and replace if necessary.
Vapor separator needle valve is bend or wear - Replace needle valve.
Restricted fuel lines - Fuel lines need to be cleaned.
Fuel tank air vent closed or restricted - Open or clean air vent.
Clogged fuel filter - Replace or clean fuel filter.
Intake manifold is air leaking - Replace intake manifold gasket.
Water intake screen is dirty - Clean and wash as required.
Throttle valve and throttle link are defective or worn - Replace faulty parts.
Fuel injector is dirty or worn - Replace or clean as required.
| Engine is overheated |
Engine overload - Load reducing required.
Fuel injector or fuel pump is clogged - Replace or clean if necessary.
Improper ignition timing - Set the ignition timing correctly.
Faulty thermostat - Change thermostat as required.
Water pump failure - Install new water pump.
Improper propeller diameter or pitch - Check the propeller size.
Damaged or bent propeller - Replace propeller.
Outboard engine is positioned too low or too high - Position the engine correctly.
Insufficient engine oil - Fill up the engine oil.
Defective oil pump - Replace oil pump.
Water intake is blocked - Need to wash or clean.
Incorrect valve setting - Set the valves correctly.
| Abnormal engine knocking or noise |
Low octane gasoline - Change fuel.
Excessive engine load - Reduce the load.
Incorrectly set low idle speed - Correct idle settings.
Clogged or damaged fuel pump - Clean or install new fuel pump.
Crankshaft or main bearings failure - Change defective components as required.
Worn cylinder bore or piston rings - Change defective parts.
| Lack of engine power |
Fuel lines are clogged - Fuel lines need to be cleaned.
Fuel injector is defective - Test fuel injector and replace if necessary.
Fuel pump is dirty or defective - Service or replace fuel pump.
Defective ignition - Inspect ignition system and change failed components.
Cylinder head gasket is damaged - Replace the gasket as required.
Powerhead parts are worn out - Change defective parts.
Valves are burned or stuck - Change or service valves.
Improper propeller diameter or pitch - Check the propeller size.
Damaged or bent propeller - Replace propeller.
Engine mounted at wrong transom height - Adjust the engine to correct transom height.
Trim angle is incorrect - Adjust trim angle.
| Excessive fuel consumption |
Damaged or clogged fuel injector - Clean or replace as required.
Spark plug is loose or faulty - Spark plug need to be replaced or tightened.
Worn sleeve, piston, or rings - Replace defective parts as required.
Electronic control unit failure - Replace ECU.
| Engine vibrates excessively |
Damaged or bent propeller - Have propeller repaired or replaced.
Propeller shaft malfunction - Propeller shaft needs to be replaced.
Weeds clogs the propeller - Remove and clean propeller.
Engine mounting bolt is not tightened - Tighten the bolt as required.
Damaged or loose steering pivot Tighten correctly or replace.
| Starter is not working |
Low battery power - Charge the battery.
Battery does not hold charge - Service charging system or replace battery.
Battery cables are disconnected or terminals are faulty - Connect wires properly or change terminals.
Starter motor is faulty - Starter should be changed.
| Trim motor runs but trim system does not move up or down |
Oil level low - Fill up oil.
Defective pump assembly - Test pump and replace if necessary.
Leakage of manual drain valve - Close the valve or change it.
Pump driveshaft or motor damaged - Change defective component.
| Trim cannot be fully up or down |
Defective pump assembly - Change pump.
Tilt ram piston ball is not positioned correctly - Clean or repair.
Tilt ram piston O-ring is worn - Change O-ring.
Lack of oil - Fill up oil to required level.
Lower check valve not seating in port side trim ram - Install valve correctly.
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