Troubleshooting; Starter Motor Will Not Crank The Engine (Electric Start Models); Engine Will Not Start; Engine Runs Erratically - Mercury 25 Jet FourStroke Operation, Maintenance And Installation Manual

Starter Motor will not Crank the Engine (Electric Start Models)

POSSIBLE CAUSES
•
Blown fuse in the starting circuit. Refer to Maintenance section.
• Outboard is not shifted to neutral position.
• Weak battery or battery connections are loose or corroded.
• Ignition key switch failure.
• Wiring or electrical connection faulty.
• Starter motor or starter solenoid failure.
• Impeller is stuck due to blockage.

Engine Will Not Start

POSSIBLE CAUSES
NOTE: If the outboard has run out of fuel, or has been in storage for an
extended period of time, additional attempts to start the engine will be required
to purge the fuel system of air.
• Lanyard stop switch not in "RUN" position.
•
Incorrect starting procedure. Refer to Operation section.
• Old or contaminated gasoline.
•
Engine flooded. Refer to Operation section.
• Fuel is not reaching the engine.
• Fuel tank is empty.
• Fuel tank vent not open or restricted.
• Fuel line is disconnected or kinked.
• Primer bulb not squeezed.
• Primer bulb check valve is faulty.
• Fuel filter is obstructed. Refer to Maintenance section.
• Fuel pump failure.
• Fuel tank filter obstructed.
•
Open 20‑amp fuse. Refer to Maintenance section.
• Ignition system component failure.
• Wiring or electrical connection faulty.
•
Spark plugs fouled or defective. Refer to Maintenance section.

Engine Runs Erratically

POSSIBLE CAUSES
• Overheating ‑ Warning horn not working.
• Low oil pressure. Check oil level.
•
Spark plugs fouled or defective. Refer to Maintenance section.

TROUBLESHOOTING

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