The Procedures for Winterizing a Boat Engine

Proper winterization insures your outboard will be ready for spring.

Any boat engine that will be stored in an unheated environment in below-freezing temperatures needs to be winterized to withstand the cold and to keep the motor's bare metal parts lubricated and the lower unit free from moisture and potential damage.

Fill Gas Tank

To avoid water condensing in the fuel tank, fill the boat's gas tank and add gasoline stabilizer, which will keep the gasoline fresh for several months.

Fog the Motor

With the motor running, spray marine engine fogging oil into the air intake for the motor for several seconds. The motor's exhaust will blow out a lot of smoke as the excess oil enters the combustion chamber. Stop adding fogging oil when the motor dies or begins to run very rough. The fogging oil coats the pistons, rings and cylinders to keep them rust free while the motor is stored.

Draining Outboard Motor

Outboard motors are cooled by water pumped from the lake (or other body of water), through the engine and back out. Some water can remain in the motor's cooling system when the motor is shut off if the motor is tilted up to keep the lower unit out of the water or while it is being hauled on a trailer. Drain the motor and lower unit by lowering the motor down to the normal operating position while the boat is out of the water.

Lower Unit Maintenance

Lower unit oil needs to be changed annually and doing it as a winterizing project insures there will not be any moisture or water in the lower unit during winter storage. Drain the old gear lube from the lower unit and pump in fresh oil.

References

• Lakeside Marine: Do it Yourself Outboard Engine Winterizing

Resources

• Boat Safe: BRRR - It's Almost That Time Again