Outboard and Antifreeze

Outboard and Antifreeze

by Conrad & Judy Kreuter

Q: Dear Boat Talk: This year I bought a new four stroke outboard engine. How do I protect the engine against freezing during the winter lay-up season? My marina always put antifreeze into the block of my I/O four stroke engine. Should that be done to my outboard? PA, Greenlawn NY

A: Dear PA: The four stroke inboard/outboard engine is installed in your boat in such a manner that the cooling water can not completely drain out when the engine is not operating. When winterizing the engine, the mechanic removes the engine and manifold drain screws to drain the block of water and replaces it with antifreeze to protect the block from freeze damage.

Your four stroke outboard block is able to self-drain each time the motor has been run. Since there is no water within the block you do not have to worry about freeze damage. When storing the motor for the winter, keep the motor in the vertical position so that water will not get trapped. The same holds true with the two-stroke engine.

Antifreeze should also be added to the fresh water systems in your boat. In most applications raw water washdown systems are usually just drained.