Engine Will Not Start Or Is Hard To Start; Poor Performance; Engine Runs Rough, Misses, Or Backfires; Excessive Engine Temperature - Mercury MerCruiser Owner's Manual

Engine Will Not Start or Is Hard to Start

Lanyard stop switch activated.
Improper starting procedure.
Insufficient fuel supply.
Faulty ignition system component.
Clogged fuel filter.
Stale or contaminated fuel.
Fuel line or tank vent line kinked or clogged.
Faulty wire connections.
EFI system fault.

Poor Performance

Throttle not fully open.
Damaged or improper propeller.
Excessive bilge water.
Boat overloaded or load improperly
distributed.
Flame arrestor dirty.
Boat bottom fouled or damaged.
Ignition problem.
Engine overheating.
EFI System fault

Engine Runs Rough, Misses, or Backfires

Clogged fuel filter.
Stale or contaminated fuel.
Kinked or clogged fuel line or fuel tank vent line.
Flame Arrestor dirty.
Faulty ignition system component.
Idle speed too low.
EFI System fault.

Excessive Engine Temperature

Water inlet or seacock closed.
Drive belt loose or in poor condition.
90-899883295 JUNE 2008
Possible Cause
Possible Cause
Possible Cause
Possible Cause
Check the lanyard stop switch.
Read the starting procedure.
Fill fuel tank or open valve.
Service the ignition system.
Replace fuel filter.
Drain fuel tank. Fill with fresh fuel.
Replace kinked lines or blow out lines with compressed air to
remove obstruction.
Check wire connections.
Have EFI System checked by an authorized Mercury
MerCruiser dealer.
Inspect the throttle cable and linkages for proper operation.
Replace the propeller.
Drain and check for cause of entry.
Reduce load or redistribute load more evenly.
Clean the flame arrestor.
Clean or repair as necessary.
See Engine Runs Rough, Misses or Backfires.
See Excessive Engine Temperature.
Have EFI System checked by an authorized Mercury MerCruiser
dealer.
Replace filter.
If contaminated, drain tank. Fill with fresh fuel.
Replace kinked lines or blow out lines with compressed air
to remove obstruction.
Clean Flame Arrestor.
Service ignition system.
Have EFI system checked by an authorized Mercury
MerCruiser dealer.
Have EFI System checked by an authorized Mercury
MerCruiser dealer.
Open.
Replace or adjust belt.
Section 7 - Troubleshooting
Remedy
Remedy
Remedy
Remedy
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