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| Home / Outboard Engines / Mercury Engines / Mercury 30 EFI |
Mercury 30 EFI Troubleshooting
| Engine will not start or starts up hard |
Fuel tank is empty - Add fuel.
Wrong fuel grade - Change gasoline.
Air in the fuel pipes - Bleed the fuel pipes.
Damaged spark plug wiring connection - Inspect the spark plug wire connection, replace or repair.
Spark plug is damaged - Replace spark plug.
Dirty fuel filter - Replace fuel filter.
Clogged fuel lines - Fuel lines need to be cleaned.
Drained or faulty battery - Change or recharge battery.
Wiring harness connections are damaged - Check electrical wire harness connections.
Damaged ignition system - Replace defective components.
Defective pulse fuel pump - Change pulse fuel pump.
Electric fuel pump is faulty - Change electric fuel pump.
ECM failure - Change electronic control modul.
| Engine starts but stalls immediately |
Faulty spark plug - Change spark plug.
Ignition coil is faulty - Ignition coil should be replaced.
Damaged pulse fuel pump - Change pulse fuel pump as required.
Restrictions in fuel system - Fuel system need to be cleaned.
Final fuel filter is clogged - Change final filter.
Damaged electric fuel pump - Change electric fuel pump.
| Irregular engine running |
Defective ignition system - Inspect ignition system and change faulty parts.
Fuel pump is clogged or faulty - Check fuel pump and replace if necessary.
Dirty fuel lines - Clean fuel lines.
Dirty fuel filter - Fuel filter needs changing.
| Engine overheated |
Engine is running overloaded - Load reducing is recommended.
Ignition timing is incorrect - Ignition timing needs to be set properly.
Damaged thermostat - Change thermostat.
Water pump malfunction - Change water pump.
| Engine knocking or noise |
Low octane fuel - Use proper gasoline.
Engine is running overloaded - Reduce the load.
Low idle speed adjustment is incorrect - Need to adjust idle speed.
Clogged or defective fuel pump - Clean or replace fuel pump.
Worn crankshaft or main bearings - Have bearings or crankshaft replaced.
Damaged piston rings or cylinder bore - Change defective parts.
| Engine loses power |
Clogged or defective fuel pump - Clean or install new fuel pump.
Defective ignition system - Check ignition and replace faulty components.
Powerhead parts are damaged - Change defective components.
Stator, coil, or switch box defective - Replace faulty parts.
Compression is insufficient - Correct.
Fuel supply problem - Check and repair.
Manifold fuel leak - Leak must be repaired.
Vapor separator is flooded - Normalize vapor separator functions.
| Excessive fuel consumption |
Spark plug is faulty or loose - Replace or tighten spark plug.
Rings, sleeve, or piston are damaged - Replace defective components as required.
Engine is overloaded - Reduce the load.
Fuel injectors are dirty or defective - Clean or install new fuel injectors.
| Trim motor runs but system does not move |
Low oil level - Need to add the oil.
Damaged pump assembly - Inspect pump and change as required.
Leakage of manual release valve - Close the valve or change it.
Motor or pump driveshaft faulty - Change defective component.
| Trim cannot be fully up or down |
Defective pump assembly - Change pump.
Tilt ram piston ball is in wrong position - Clean or repair.
Damaged tilt ram piston O-ring - Replace O-ring.
Insufficient oil - Check and refill oil.
Lower check valve not seating in port side trim ram - Install valve correctly.
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| Engines Technical Specifications |