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| Home / Outboard Engines / Mercury Engines / Mariner 175 |
Mariner 175 Troubleshooting
| Engine Model: Mariner 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 5500 rpm |
| Fuel System: Carburetor with adjustable jet |
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| Engine doesn't start or starts hard |
No fuel in fuel tank - Add fuel.
Wrong grade of gasoline - Use correct fuel grade.
Air in the fuel pipes - Bleed the fuel pipes.
Defective wiring connection of spark plug - Check the spark plug wire connection, repair or replace.
Spark plug is faulty - Install new spark plug.
Fuel filter is dirty - Fuel filter needs to be replaced.
Wrong carburetor adjustment - Adjusting carburetor correctly.
Clogged fuel lines - Clean fuel lines.
Fuel tank air vent restricted or closed - Open or service air vent.
Lack of fuel pump pressure - Change or rebuild fuel pump.
| Engine starts but immediately shuts off |
Spark plug is damaged - Install new spark plug.
Clogged or defective carburetor - Repair or clean carburetor.
Damaged ignition coil - Change ignition coil as required.
Closed or clogged fuel tank air vent - Open or service air vent.
Lack of fuel pump pressure - Change or rebuild fuel pump.
Faulty thermal relief valve - Change as required.
| Irregular engine running |
Defective ignition system - Check ignition and replace faulty components.
Dirty or damaged fuel pump - Service or replace fuel pump.
Carburetor settings incorrect - Adjusting as required.
Dirt in the fuel lines - Fuel lines need to be cleaned.
Fuel tank air vent closed or restricted - Fuel tank air vent need to be opened or cleaned.
Plugged fuel filter - Replace fuel filter.
Damaged gaskets - Install new gaskets.
| Engine overheats |
Engine overloaded - Load reducing is recommended.
Carburetor fuel mixture is too lean - Make the correct settings.
Wrong ignition timing - Set the ignition timing properly.
Thermostat is defective - Install new thermostat.
Water pump failure - Change water pump.
| Engine knocking sound or abnormal noise |
Stale gasoline - Use correct gasoline.
Engine overload - Load reducing is recommended.
Too low idle RPM - Adjust the low idle speed.
Dirty or defective fuel pump - Service or replace fuel pump.
Worn crankshaft or main bearings - Worn parts replacement required.
Damaged piston rings or cylinder bore - Replace defective components.
| Engine power loss |
Carburetor is dirty or incorrectly adjusted - Adjust the carburetor properly or clean it.
Dirty or damaged fuel pump - Service or replace fuel pump.
Ignition failure - Check ignition and replace faulty components.
Worn gaskets - Replace gaskets.
Worn powerhead parts - Replace defective components.
| Excessive fuel consumption |
Carburetor main jet is incorrectly adjusted - Adjust it properly.
Loose or defective spark plug - Replace or tighten spark plug.
Worn sleeve, piston, or rings - Change faulty components.
| Trim motor is running but system can't move |
Not enough oil - Need to add the oil.
Pump assembly faulty - Check pump and replace if necessary.
Leakage of manual drain valve - Valve need to be closed or changed.
Faulty pump driveshaft or motor - Change worn component.
| Trim does not fully up or down |
Pump assembly is faulty - Change pump as required.
Tilt ram piston ball is displaced - Service or repair.
Tilt ram piston O-ring is worn - Replace O-ring.
Insufficient oil - Check and refill oil.
Lower check valve not seating in port side trim ram - Secure valve properly.
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