How to Winterize Your Outboard Motor: Step-by-Step

Winterizing protects your outboard from the two biggest causes of spring start-up problems: stale fuel gumming the carburettor, and moisture corroding internal cylinder surfaces.

Why it matters

Modern ethanol-blended fuel degrades faster than older fuel formulations and can leave gum deposits in a carburettor left sitting over winter — the single most common reason an outboard won't start in spring.

Fuel stabiliser

Add a fuel stabiliser to the tank and run the engine briefly so treated fuel reaches the carburettor, not just the tank.

Fogging oil

Fogging oil sprayed into the air intake while the engine runs briefly coats internal cylinder surfaces, preventing corrosion during months of inactivity.

Storage position

Store the engine upright (or in the specific position your manual states) to prevent oil pooling incorrectly, and keep it under a cover if stored outdoors.

For a full annual maintenance schedule beyond winterizing, see our maintenance guide.