________________________________________________________________________________________
| Home / Outboard Engines / Mercury Engines / Mercury 15 Sea Pro |
Mercury Sea Pro 15 Troubleshooting
| Engine hard starting or not starting |
Gas tank is empty - Add gasoline.
Improper fuel grade - Change fuel.
Clogged fuel system - Remove clogging.
Faulty spark plug wire connection - Inspect the spark plug wire connection, replace or repair.
Faulty spark plug - Change spark plug as required.
Fuel filter is clogged - Install new filter.
Incorrect carburetor adjustment - Adjust carburetor idle mixture screw.
Dirty fuel lines - Fuel lines need to be cleaned.
Fuel tank air vent closed or restricted - Open or service air vent.
Fuel pump pressure is low - Repair or change fuel pump.
| Engine starts but stalls suddenly |
Spark plug is defective - Install new spark plug.
Defective or dirty carburetor - Clean or install new carburetor.
Defective ignition coil - Replace ignition coil as necessary.
Closed or restricted fuel tank air vent - Fuel tank air vent need to be opened or cleaned.
Lack of fuel pump pressure - Repair or change fuel pump.
Thermal relief valve is faulty - Replace if necessary.
| Rough engine running |
Defective ignition - Inspect ignition system and change failed components.
Dirty or damaged fuel pump - Clean or change fuel pump.
Carburetor settings incorrect - Adjusting as required.
Clogged fuel lines - Fuel lines must be clean.
Fuel tank air vent clogged or closed - Open or service air vent.
Fuel filter is clogged - Replace fuel filter.
Gaskets are worn - Replace gaskets.
| Engine overheating |
Engine is under excessive load - Load reducing required.
Too lean fuel mixture in carburetor - Set the carburetor properly.
Bad ignition timing - Set the ignition timing correctly.
Thermostat is faulty - Change thermostat as required.
Water pump malfunction - Replace water pump.
| Engine noise or knocking |
Low octane fuel - Change gasoline.
Engine is running overloaded - Reduce engine load.
Too low idle RPM - Adjust as required.
Fuel pump is damaged or dirty - Service or change fuel pump.
Main bearings or crankshaft wear - Worn parts replacement required.
Damaged piston rings or cylinder bore - Replace faulty parts.
| Low engine power |
Carburetor is improperly adjusted or dirty - Clean or properly adjust carburetor.
Clogged or defective fuel pump - Clean or change fuel pump.
Ignition system is defective - Inspect ignition system and change failed components.
Gaskets are damaged - Change gaskets.
Worn powerhead parts - Replace defective parts.
| Engine uses too much fuel |
Carburetor main jet is improperly adjusted - Adjust it correctly.
Faulty or loose spark plug - Spark plug need to be replaced or tightened.
Piston, sleeve, or rings are damaged - Change faulty parts.
| Trim motor runs but system does not move |
Oil level is low - Checking oil level and add if necessary.
Pump assembly is damaged - Check pump and change if required.
Manual release valve leaking - Close the valve fully or replace it.
Broken motor or pump driveshaft - Replace worn component.
| Trim does not fully up or down |
Damaged pump assembly - Change pump as required.
Tilt ram piston ball is not positioned correctly - Clean or repair.
Tilt ram piston O-ring damaged - Install new O-ring.
Oil level is insufficient - Fill up oil.
Lower check valve is not properly secured in port side trim ram - Secure valve properly.
________________________________________________________________________________________
________________________________________________________________________________________
| Engines Technical Specifications |