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| Home / Outboard Engines / Mercury Engines / Mercury 50 Bigfoot |
Mercury 50 Bigfoot Troubleshooting
| Engine will not start or starts up hard |
No fuel in fuel tank - Fill it up.
Low-quality gasoline - Use quality fuel.
Fuel system clogged - Repair or replace.
Spark plug wiring connection is damaged - Inspect spark plug wiring connection, change or repair.
Damaged spark plug - Replace spark plug.
Clogged fuel filter - Fuel filter needs changing.
Fuel lines are clogged - Service fuel lines.
Drained or faulty battery - Recharge or change battery.
Wiring harness connections are damaged - Inspect harness connections.
Damaged ignition system - Check ignition components and replace if necessary.
Faulty pulse fuel pump - Replace pulse fuel pump.
Electric fuel pump is faulty - Electric fuel pump need to be replaced.
ECM failure - Change electronic control modul.
| Engine starts and stops suddenly |
Defective spark plug - Replace spark plug.
Defective ignition coil - Ignition coil must be replaced.
Defective pulse fuel pump - Change pulse fuel pump.
Fuel system clogging - Clean fuel system.
Dirty final fuel filter - Final filter needs changing.
Defective electric fuel pump - Electric fuel pump need to be replaced.
| Engine runs intermittently |
Ignition failure - Check ignition and replace faulty components.
Fuel pump is clogged or faulty - Clean or change fuel pump.
Fuel lines are clogged - Fuel lines must be clean.
Fuel filter is dirty - Replace fuel filter.
| Engine overheated |
Excessive engine load - Load reducing is recommended.
Ignition timing is incorrect - Set the ignition timing properly.
Defective thermostat - Replace thermostat.
Water pump is defective - Install new water pump.
| Engine knocking or noise |
Low octane fuel - Use proper gasoline.
Engine overload - Load reducing is recommended.
Low idle speed adjustment is incorrect - Adjust the low idle speed.
Dirty or defective fuel pump - Service or change fuel pump.
Worn main bearings or crankshaft - Repair or replace defective parts.
Piston rings or cylinder bore are worn - Change defective parts.
| Loss of engine power |
Clogged or damaged fuel pump - Inspect fuel pump and change as required.
Ignition failure - Check ignition and replace faulty components.
Damaged powerhead parts - Replace defective components.
Failed switch box, stator, or coil - Replace faulty parts.
Bad compression - Correct.
Fuel supply problem - Check and repair.
Manifold is leaking - Leak must be repaired.
Vapor separator is flooded - Normalize vapor separator functions.
| Excessive fuel consumption |
Spark plug is defective or loose - Spark plug need to be replaced or tightened.
Sleeve, piston, or rings are damaged - Replace defective components.
Engine overload - Reduce engine load.
Fuel injectors are clogged or faulty - Service or replace fuel injectors.
| Trim motor runs but system does not move |
Low oil level - Check and refill oil.
Defective pump assembly - Inspect pump and change as required.
Manual shut-off valve leaks - Close the valve or change it.
Pump driveshaft or motor damaged - Change worn component.
| Trim does not fully up or down |
Pump assembly is defective - Change pump.
Tilt ram piston ball is displaced - Service or repair.
Damaged tilt ram piston O-ring - Install new O-ring.
Low oil level - Check and refill oil.
Lower check valve is not properly secured in port side trim ram - Secure valve properly.
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| Engines Technical Specifications |