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| Home / Outboard Engines / Mercury Engines / Mercury 20 ELH |
Mercury 20 ELH Troubleshooting
| Engine will not start or hard to start |
Empty gas tank - Add fuel.
Improper fuel grade - Change gasoline.
Air or water in fuel system - Remove water or air from fuel system.
Spark plug wire is disconnected or loose - Inspect spark plug wiring connection, change or repair.
Spark plug is faulty - Change spark plug.
Clogged fuel filter - Replace or clean fuel filter.
Dirty fuel lines - Clean fuel system lines.
Drained or faulty battery - Charge or replace the battery.
Damaged wiring harness connections - Check electrical wire harness connections.
Ignition system malfunction - Replace defective components.
Faulty pulse fuel pump - Change pulse fuel pump.
Electric fuel pump is faulty - Install new electric fuel pump.
Electronic control modul failure - Replace ECM.
| Engine starts and stops immediately |
Spark plug is damaged - Replace spark plug.
Ignition coil is not working - Replace ignition coil as necessary.
Pulse fuel pump is faulty - Replace pulse fuel pump.
Restrictions in fuel system - Clean fuel system.
Final fuel filter is clogged - Change final filter.
Damaged electric fuel pump - Replace electric fuel pump.
| Rough engine running |
Ignition system malfunction - Test ignition and replace failed parts.
Clogged or defective fuel pump - Inspect fuel pump and change as required.
Dirt in the fuel lines - Service fuel lines.
Fuel filter is dirty - Fuel filter needs changing.
| Engine is overheated |
Engine is running overloaded - Reduce load.
Ignition timing is wrong - Set the ignition timing correctly.
Thermostat failure - Thermostat need to be replaced.
Water pump is defective - Change water pump.
| Engine noise or knocking |
Low octane fuel - Use correct fuel.
Excessive engine load - Load reducing is recommended.
Low idle speed setting is not correct - Adjust idle speed.
Fuel pump is faulty or clogged - Test fuel pump and replace if necessary.
Crankshaft or main bearings wear - Need to install new components.
Piston rings or cylinder bore are worn - Replace defective parts.
| Lack of engine power |
Fuel pump is faulty or clogged - Test fuel pump and replace if necessary.
Ignition failure - Check ignition system and replace faulty parts.
Worn powerhead parts - Change defective parts.
Failed switch box, stator, or coil - Change faulty components.
Low compression - Normalize compression.
Fuel delivery problem - Check and repair.
Manifold is leaking - Leak must be repaired.
Vapor separator is flooded - Check and correct malfunction.
| Engine using too much gasoline |
Spark plug is defective or loose - Re-tighten or change the spark plug.
Worn sleeve, rings, or piston - Change defective parts.
Engine overload - Load reducing required.
Dirty or faulty fuel injectors - Check fuel injectors and replace if necessary.
| Trim motor runs but system does not move |
Oil insufficient - Checking oil level and add if necessary.
Pump assembly is faulty - Inspect pump and change as required.
Manual shut-off valve leaks - Close the valve fully or replace it.
Broken motor or pump driveshaft - Change defective component.
| Trim does not fully up or down |
Pump assembly is defective - Change pump.
Tilt ram piston ball is not positioned correctly - Clean or repair.
Worn tilt ram piston O-ring - Install new O-ring.
Lack of oil - Checking oil level and add if necessary.
Lower check valve not seating in port side trim ram - Install valve correctly.
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| Engines Technical Specifications |