Mercury Marine Outboard Engine
Periodic Maintenance Service Schedule
Required Service Item

1 year or
100 hours' use

3 years or
300 hours' use


Thermostat inspection1

Engine timing verification/Drive belt inspection

Drive shaft splines lubrication

Valve clearance inspection/ adjustment

Control cable adjustment

Water pump impeller replacement1,2

Fuel system service/inspection1

Gear lube replacement
Engine oil and filter replacement (Mercury FourStroke models)

These items may require more frequent intervals if exposed to contaminates that increase wear of impeller or clog passages or filters.
2 OptiMax® 135/150/175HP models require annual water pump impeller replacement.
Verado® models and current 75HP – 115HP FourStroke models do not require periodic valve adjustment

The information provided above is courtesy Mercury Marine and is provided as a courtesy to Power Source Marine's customers. Power Source Marine provides no warranty on the accuracy of the information. If you have a question about the information presented here, please contact us.