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Tohatsu MD30B2 Troubleshooting
The Tohatsu MD30B2 is a 2-stroke 3-cylinder inline TLDI forced water-cooled gasoline outboard engine with a rated power of 30 hp (22.1 kW) at 5150-5850 rpm. The engine cylinder bore is 2.68" (68 mm) and piston stroke is 2.52" (64 mm). A 42.5 cubic inches (697 cc) outboard motor has a two stroke low pressure direct injection fuel system, starting system with electric starter, inductive ignition system, forward-neutral-reverse gear shifting, power trim/tilt, and handle tiller or remote control steering. The fuel tank capacity is 6.6 gal (25 liters). The propeller is made of aluminum and it has three blades.
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| Engine will not start or hard to start |
No gasoline in tank - Fill it up.
Improper fuel grade - Use quality fuel.
Water or air in fuel system - Remove air or water from system.
Spark plug wire is loose or disconnected - Check spark plug wiring connection, repair or change.
Spark plug is damaged - Spark plug need to be replaced.
Fuel filter is plugged - Change fuel filter.
Fuel lines clogging - Clean fuel system lines.
Low fuel pressure - Check low pressure fuel pump or check system for fuel leaks.
Low air pressure - Normalize air pressure.
Bad harness connections - Inspect harness connections.
Ignition system is damaged - Change defective parts.
Fuel feed pump is defective - Fuel feed pump need to be replaced.
Dirty or faulty fuel injector - Clean or replace as required.
Electronic control modul failure - Replace ECM.
Damaged or worn fuel reed valve - Replace reed valve as required.
| Engine starts and stalls immediately |
Faulty spark plug - Replace spark plug.
Ignition coil is damaged - Ignition coil should be replaced.
Pulse pump is defective - Replace fuel pump.
Fuel system is clogged - Service fuel system.
Dirty fuel filter - Fuel filter needs changing.
| Engine runs intermittently |
Ignition system malfunction - Check ignition and replace faulty components.
Defective spark plug - Spark plug need to be replaced.
Fuel pump is damaged or dirty - Clean or change fuel pump.
Air pressure is low - Inspect air system for leaks.
Fuel lines are clogged - Clean fuel system lines.
Plugged fuel filter - Replace or clean fuel filter.
Direct injector is faulty - Install new injector.
| Engine is overheated |
Engine overloaded - Reduce load.
Incorrect ignition timing - Ignition timing needs to be set properly.
Damaged thermostat - Thermostat need to be replaced.
Faulty water pump - Water pump need to be replaced.
Incorrect propeller selection - Replace propeller.
Damaged or bent propeller - Have propeller repaired or replaced.
Outboard engine is positioned too low or too high - Mount the motor as required.
| Engine knocks or noises |
Stale gasoline - Use proper gasoline.
Engine overload - Load reducing required.
Low idle speed adjustment is incorrect - Correct idle settings.
Clogged or damaged fuel pump - Test fuel pump and change if necessary.
Crankshaft or main bearings failure - Need to install new components.
Cylinder bore or piston rings are worn - Change defective parts.
| Engine loses power |
Dirty or faulty fuel pump - Clean or install new fuel pump.
Ignition system is defective - Test ignition and replace failed parts.
Worn powerhead parts - Replace defective parts as required.
Fuel pressure is low - Check system for fuel leaks or check low pressure fuel pump.
Air pressure is low - Inspect air system for leaks.
Bad compression - Correct it.
Fuel delivery problem - Check fuel system.
Fuel regulator is leaking - Leak must be repaired.
Clogged fuel filter - Fuel filter needs changing.
Damaged or clogged fuel injector - Replace or clean if necessary.
Manifold fuel leak - Repair leaks.
Propeller pitch or diameter incorrect - Replace propeller.
Damaged or improper size of propeller - Have propeller repaired or replaced.
Outboard engine mounting height improperly - Check the outboard engine mounting height.
Improper trim angle - Make the correct trim angle adjustment.
| High fuel consumption |
Spark plug is loose or defective - Tighten or replace spark plug.
Sleeve, rings, or piston are damaged - Change faulty parts.
Engine is running overloaded - Reduce load.
Dirty or damaged fuel injectors - Check fuel injectors and change if required.
| Motor vibrates excessively |
Damaged or improper size of propeller - Have propeller repaired or replaced.
Propeller shaft malfunction - Propeller shaft needs to be replaced.
Weeds wraped around propeller - Remove and clean propeller.
Motor mounting bolt is loose - Tighten bolt.
Loose or faulty steering pivot - Tighten or replace.
| Starter motor won't turn |
Damaged or improper size of propeller - Replace propeller.
Propeller shaft damaged - Have propeller shaft replaced.
Weeds in the propeller - Remove and clean propeller.
Motor mounting bolt is loose - Tighten the bolt as required.
| Trim motor is running but trim system cannot move up or down |
Oil level is insufficient - Need to add the oil.
Damaged pump assembly - Check pump and change if required.
Manual shut-off valve leaks - Valve need to be closed or changed.
Broken motor or pump driveshaft - Change worn component.
| Trim does not fully up or down |
Damaged pump assembly - Change pump.
Tilt ram piston ball is not positioned correctly - Service or repair.
Tilt ram piston O-ring is worn - Install new O-ring.
Low oil level - Fill up oil.
Lower check valve not seating in port side trim ram - Secure valve properly.
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