Mercury 40 Jet Manual page 75

• Check the engine water separating fuel filter for contaminants.
Clean or replace the filter. See Fuel System.
• Check the corrosion control anode. Check more frequently
when used in saltwater. See Corrosion Control Anode.
• Drain and replace the gearcase lubricant. See Gearcase
Lubrication.
• Check the power steering fluid. See Checking Power Steering
Fluid.
• Inspect the battery. See Battery Inspection.
• Check the wiring and connectors.
• Check the tightness of bolts, nuts, and other fasteners.
• Saltwater usage. Remove and inspect the spark plugs for
corrosion and replace the spark plugs as necessary. Apply a
thin coating of Anti‑Seize Compound only on the threads of
the spark plugs prior to installation. See Spark Plug
Inspection and Replacement.
Tube Ref No.
Anti-Seize
81
Compound
EVERY 300 HOURS OF USE OR THREE YEARS
IMPORTANT: The engine oil must be drained before removing the
gearcase to avoid oil spillage. Perform the scheduled water pump
replacement in combination with an engine oil change.
• Replace the water pump impeller. Replace the impeller more
often if overheating occurs or if reduced water pressure is
1.
noted.
• Check the power trim fluid. See Checking Power Trim
Fluid.
•
Replace the high‑pressure in‑line fuel filter.
• Replace the spark plugs at the first 300 hours or third year.
After that, inspect the spark plugs every 300 hours or three
years. Replace the spark plugs as needed. See Spark Plug
Inspection and Replacement.
MAINTENANCE
Description
67
Where Used
Spark plug threads
1.
Part No.
92-881091K
1