Section 7 - Troubleshooting
90-8M0074347
eng
OCTOBER 2012
Page 111
Engine Runs Rough, Misses, or Backfires
Possible Cause
Remedy
Clogged fuel filter.
Replace filter.
Stale or contaminated fuel.
Drain fuel tank. Fill with fresh fuel.
Kinked or clogged fuel line or fuel tank vent line. Replace kinked lines or blow out lines with compressed air to remove
obstruction.
Flame arrestor dirty.
Clean the flame arrestor.
Faulty ignition system component.
Service ignition system.
Idle speed too low.
Have EFI system checked by an authorized Mercury MerCruiser dealer.
EFI system fault.
Have EFI system checked by an authorized Mercury MerCruiser dealer.
Poor Performance
Possible Cause
Remedy
Throttle not fully open.
Inspect the throttle cable and linkages for proper operation.
Damaged or improper propeller.
Replace the propeller.
Excessive bilge water.
Drain and check for cause of entry.
Boat overloaded or load improperly distributed.
Reduce load or redistribute load more evenly.
Flame arrestor dirty.
Clean the flame arrestor.
Boat bottom fouled or damaged.
Clean or repair as necessary.
Ignition problem.
See
Engine Runs Rough, Misses, or Backfires
.
Engine overheating.
See
Excessive Engine Temperature
.
EFI system fault.
Have EFI system checked by an authorized Mercury MerCruiser dealer.
Troubleshooting Charts Specifically for 3.0 TKS
Starter Motor Will Not Crank Engine, or Cranks Slow
Possible Cause
Remedy
Battery switch turned off.
Turn the switch on.
Remote control not in the neutral position.
Position the control lever in neutral.
Open circuit breaker or blown fuse.
Check and reset the circuit breaker or replace fuse.
Loose or dirty electrical connections or damaged
wiring.
Check all electrical connections and wires (especially battery cables).
Clean and tighten all faulty connections.
Bad battery or low battery voltage.
Test the battery and charge if necessary; replace if bad.
Lanyard stop switch activated.
Check the lanyard stop switch.
Engine Will Not Start or Is Hard to Start
Possible Cause
Remedy
Lanyard stop switch activated.
Check the lanyard stop switch.
Improper starting procedure.
Read the starting procedure.
Insufficient fuel supply.
Fill fuel tank or open valve.
Engine flooded.
Turn the key switch off and wait five minutes. Push the throttle only button,
push the remote control handle/throttle lever to the 1/4 throttle position, and
attempt to restart.
Faulty ignition system component.
Service the ignition system.
Clogged fuel filter.
Replace fuel filter.