Mercury 3.0 MPI ECT User Manual

Section 6 - Troubleshooting
Page 90 90-8M0113856 eng DECEMBER 2015
Possible Cause Remedy
Stale or contaminated fuel. Drain fuel tank. Fill with fresh fuel.
Fuel line or tank vent line kinked or clogged.
Replace kinked lines or blow out lines with compressed air to remove
obstruction.
Faulty wire connections. Check wire connections.
TKS fuse blown. Check TKS fuse. Replace the fuse if blown.
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 flame arrestor.
Faulty ignition system component. Service ignition system.
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.
Running rich. Have authorized Mercury MerCruiser dealer check and repair.
Troubleshooting Charts for 3.0 MPI ECT and 3.0 TKS
Excessive Engine Temperature
Possible Cause
Remedy
Water inlet or seacock closed. Open.
Drive belt loose or in poor condition. Replace or adjust belt.
Seawater pickups or sea strainer obstructed. Remove obstruction.
Faulty thermostat. Replace.
Coolant level (if equipped) low in closed cooling section.
Check for cause of low coolant level and repair. Fill system
with proper coolant solution.
Heat exchanger or fluid cooler plugged with foreign material.
Clean heat exchanger, engine oil cooler, and transmission oil
cooler (if equipped).
Loss of pressure in closed cooling section. Check for leaks. Clean, inspect, and test pressure cap.
Faulty seawater pickup pump. Repair.
Seawater discharge restricted or plugged. Clean exhaust elbows.

Mercury 3.0 MPI ECT Specifications

General

Brand	Mercury
Model	3.0 MPI ECT
Category	Outboard Motor
Language	English