Mercury 135 Verado Troubleshooting
| Engine Model: Mercury Verado 135 |
| Engine Type: 4-stroke inline 4-cylinder DOHC 16-valve gasoline outboard engine |
| Total Displacement: 105.7 cu.in (1.7 L) |
| Rated Engine Power: 135 Hp (101 kW) at 6400 rpm |
| Fuel System: Sequential Multi-Point Electronic Fuel Injection (EFI) |
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| Engine doesn't start or starts hard |
Empty fuel tank - Fill fuel up.
Wrong fuel grade - Use quality fuel.
Air trapped in fuel system - Bleed air.
Defective spark plug wire connection - Inspect spark plug wiring connection, change or repair.
Faulty spark plug - Spark plug need to be replaced.
Dirty fuel filter - Change fuel filter.
Vapor separator needle valve is worn or defective - Change vapor separator needle valve.
Restricted fuel lines - Fuel lines need to be cleaned.
Fuel tank air vent restricted or closed - Fuel tank air vent need to be opened or cleaned.
Faulty fuel feed pump - Install new feed pump or repair it.
Choke cable is worn or not adjusted properly - Adjust correctly or replace the cable.
Improper valve clearance - Adjust valve clearance according to specifications.
Valve timing is wrong - Adjust valve timing correctly.
Fuel pressure is low - Inspect fuel system for leaks or inspect low pressure fuel pump.
Dirty or faulty fuel injector - Replace or clean as required.
Fuel regulator failure - Install new fuel regulator.
ECM is faulty - Install new ECM.
| Engine starts but immediately stops |
Faulty spark plug - Install new spark plug.
Vapor separator needle valve is damaged or worn - Replace needle valve.
Damaged ignition coil - Replace ignition coil as necessary.
Closed or restricted fuel tank air vent - Open or service air vent.
Fuel pump malfunction - Replace or rebuild fuel pump.
Damaged choke system - Change choke system components as required.
Valve clearance is not correct - Check and adjust.
Valve timing is incorrect - Set the valve timing correctly.
Valve springs are loose or broken - Install new valve springs.
Stuck valves - Clean the valves.
Bad cylinder compression - Inspect and replace defective parts.
Dirty fuel filter - Fuel filter needs to be replaced.
Fuel injector is damaged or dirty - Replace or clean as required.
Engine oil level is insufficient - Fill the crankcase with engine oil.
Defective oil pump - Change oil pump.
Water intake is blocked - Clean and wash as required.
Thermostat failure - Change thermostat.
Faulty water pump - Change water pump.
Ignition system malfunction - Check ignition and replace faulty components.
Dirty or damaged fuel pump - Test fuel pump and change if necessary.
Damaged or wear vapor separator needle valve - Change vapor separator needle valve.
Fuel lines are dirty - Clean fuel system lines.
Fuel tank air vent clogged or closed - Open or service air vent.
Clogged fuel filter - Replace fuel filter.
Intake manifold air leaks - Replace intake manifold gasket.
Water intake is blocked - Need to clean or wash.
Throttle link and throttle valve are worn or damaged - Replace faulty parts.
Fuel injector is clogged or malfunction - Replace or clean as required.
Engine is under excessive load - Reduce load.
Fuel pump or fuel injector is dirty - Clean or replace as required.
Improper ignition timing - Set the ignition timing correctly.
Thermostat is defective - Install new thermostat.
Defective water pump - Change water pump as required.
Incorrect propeller selection - Replace propeller.
Propeller bent or damaged - Have propeller repaired or replaced.
Outboard motor is positioned too low or too high - Position the engine correctly.
Engine oil level low - Fill the crankcase with engine oil.
Oil pump failure - Change oil pump.
Clogged water intake - Clean and wash as required.
Improper valve setting - Valves needs to be set correctly.
Stale or low octane fuel - Use proper fuel.
Engine overloaded - Reduce load.
Wrong adjustment of low idle speed - Adjust idling as required.
Fuel pump is defective or dirty - Check fuel pump and replace if necessary.
Crankshaft or main bearings are worn out - Have bearings or crankshaft replaced.
Worn piston rings or cylinder bore - Replace defective parts.
Dirty fuel lines - Clean fuel lines.
Fuel injector malfunction - Change fuel injector.
Dirty or faulty fuel pump - Clean or replace fuel pump.
Ignition system malfunction - Check ignition and replace faulty components.
Damaged cylinder head gasket - Replace the head gasket.
Faulty powerhead components - Replace defective components.
Burned or stuck valves - Change or service valves.
Improper propeller diameter or pitch - Replace propeller.
Propeller bent or damaged - Have propeller repaired or replaced.
Incorrect outboard motor mounting height - Check the outboard engine mounting height.
Trim angle is incorrect - Adjust trim angle.
Dirty or faulty fuel injector - Clean or replace as required.
Faulty or loose spark plug - Tighten or change the spark plug.
Sleeve, piston, or rings are damaged - Replace faulty parts.
ECU failure - Install new ECU.
| Engine vibrates excessively |
Damaged or bent propeller - Replace propeller.
Propeller shaft malfunction - Replace propeller shaft.
Weeds in the propeller - Remove weeds from propeller.
Engine mounting bolt is not tightened - Tighten bolt.
Steering pivot is faulty or loose Tighten or replace.
Low battery capacity - Battery needs to be recharged.
Battery is not holding charge - Service battery or replace it.
Disconnected wires or corroded battery terminals - Check cables and service or change terminals.
Damaged starter motor - Starter should be changed.
| Trim motor runs but trim system does not move up or down |
Oil level is low - Check oil level and add oil as required.
Pump assembly is defective - Check pump and change if required.
Leakage of manual drain valve - Close the valve fully or replace it.
Motor or pump driveshaft faulty - Change worn component.
| Trim does not fully up or down |
Pump assembly is faulty - Change pump as required.
Tilt ram piston ball is in wrong position - Clean or repair.
Damaged tilt ram piston O-ring - Replace O-ring.
Low oil level - Fill up oil.
Lower check valve not seating in port side trim ram - Secure valve properly.
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