Poor Performance - Mercury D4.2L Manual

Engine Runs Rough, Misses And/Or Backfires
Possible Cause
•
Throttle not operating properly
•
Idle speed too low
•
Clogged fuel or air filters
•
Stale or contaminated fuel
•
Kinked or clogged fuel line or fuel tank
vent line
•
Air in fuel injection system
•
EDI System fault.

Poor Performance

Possible Cause
•
Throttle not fully open
•
Damaged or improper propeller
•
Excessive bilge water
•
Boat overloaded or load improperly dis-
tributed
•
Boat bottom fouled or damaged
•
EDI System fault.
•
Check throttle linkages for binding or an obstruction.
•
Check idle speed and adjust, if necessary.
•
Replace filters.
•
If contaminated, drain tank. Fill with fresh fuel.
•
Replace kinked line or blow out line with com-
pressed air to remove obstruction.
•
Purge fuel injection system.
•
Have EDI System checked by an Authorized
MerCruiser Dealer.
•
Inspect throttle cable and linkages for operation.
•
Replace.
•
Drain and check for cause of entry.
•
Reduce load or redistribute load more evenly.
•
Clean or repair as necessary.
•
Have EDI System checked by an Authorized
MerCruiser Dealer.
Remedy
Remedy
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