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| Home / Outboard Engines / Mercury Engines / Mercury 175 EFI |
Mercury EFI 175 Troubleshooting
| Engine Model: Mercury EFI 175 Hp |
| Engine Type: 2-cycle 6-cylinder gasoline outboard engine |
| Total Displacement: 153 cu.in (2507 cc) |
| Rated Engine Power: 175 Hp (130.5 kW) at 5750 rpm |
| Fuel System: Electronic fuel injection (EFI) |
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- Mercury 175 EFI Engine Specifications
- Mercury 175 EFI Engine Maintenance
- Mercury 175 EFI Engine Troubleshooting
| Engine doesn't start or hard to start |
No fuel in fuel tank - Add fuel.
Wrong grade of gasoline - Use quality fuel.
Dirty fuel system - Check and clean.
Faulty spark plug wire connection - Inspect the spark plug wire connection, replace or repair.
Faulty spark plug - Install new spark plug.
Fuel filter is clogged - Fuel filter needs changing.
Fuel lines are clogged - Fuel lines must be clean.
Discharged or worn battery - Change or recharge battery.
Damaged wiring harness connections - Inspect harness connections.
Ignition system malfunction - Replace defective components.
Pulse fuel pump is defective - Replace pulse fuel pump.
Electric fuel pump failure - Electric fuel pump need to be replaced.
Electronic control modul failure - Replace ECM.
| Engine starts and immediately shuts off |
Damaged spark plug - Install new spark plug.
Ignition coil is faulty - Change ignition coil as required.
Pulse fuel pump failure - Pulse fuel pump need to be replaced.
Fuel system clogging - Clean fuel system.
Dirty final fuel filter - Final filter needs changing.
Electric fuel pump failure - Install new electric fuel pump.
| Engine runs intermittently |
Ignition system failure - Check ignition system and replace faulty parts.
Fuel pump is clogged or faulty - Test fuel pump and change if necessary.
Fuel lines are dirty - Fuel lines must be clean.
Fuel filter is clogged - Install new filter.
| Engine is overheated |
Engine is overloaded - Reduce load.
Bad ignition timing - Ignition timing needs to be set properly.
Thermostat failure - Install new thermostat.
Defective water pump - Water pump need to be replaced.
| Engine knocks or noises |
Stale or low octane fuel - Use correct fuel.
Engine is running overloaded - Reduce engine load.
Low idle speed adjustment is incorrect - Correct idle settings.
Clogged or damaged fuel pump - Clean or install new fuel pump.
Crankshaft or main bearings failure - Have bearings or crankshaft replaced.
Damaged cylinder bore or piston rings - Change defective parts.
| Engine power loss |
Dirty or damaged fuel pump - Service or change fuel pump.
Defective ignition - Check ignition system and replace faulty parts.
Faulty powerhead parts - Change defective parts.
Stator, coil, or switch box defective - Replace damaged components.
Compression is insufficient - Normalize compression.
Fuel delivery problem - Check fuel system.
Manifold fuel leak - Leak must be repaired.
Vapor separator is flooded - Normalize vapor separator functions.
| Engine using too much gasoline |
Faulty or loose spark plug - Re-tighten or replace spark plug.
Rings, sleeve, or piston are damaged - Change faulty parts.
Engine is overloaded - Load reducing required.
Dirty or damaged fuel injectors - Check fuel injectors and change if required.
| Trim motor runs but system does not move |
Not enough oil - Check oil level and add oil as required.
Defective pump assembly - Check pump and change if required.
Leakage of manual drain valve - Close the valve fully or replace it.
Broken motor or pump driveshaft - Change 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.
Damaged tilt ram piston O-ring - Change O-ring.
Insufficient oil - Checking oil level and add if necessary.
Lower check valve is not properly secured in port side trim ram - Install valve correctly.
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| Engines Technical Specifications |