How to Winterize an Outboard Motor In 6 Steps

Knowing how to winterize an outboard motor is essential for the overall health and performance of your boat. Proper winterization protects against corrosion and freeze damage that can occur while your motor is in winter storage.

Here’s everything you need to know about how to winterize an outboard motor.

1. Change the Crankcase Oil

If you have a four-stroke engine, it’s important to change the oil before you store your motor for the winter. The oil will be dirty and full of contaminants after summer use, and over the course of the winter months, these contaminants can corrode your engine. This can shorten the engine’s life and leave you with repairs to make in the spring.

2. Change the Gear Oil

The gear oil needs to be changed before winter for the same reason as the crankcase oil: There are contaminants in it. Drain the old gear oil, and replace it with fresh oil before you store the motor.

3. Stabilize the Fuel

Cold weather is hard on fuel. To keep your fuel from going bad over the winter, treat it with a stabilizer that will prevent it from getting gummy. Once you add the stabilizer, be sure to circulate it through your engine by attaching flushing muffs with a hose to provide water. Make sure you let the motor run for 10 minutes when you add stabilizer.

4. Fog the Engine

Treating the engine with fogging oil helps prevent engine corrosion. Ideally, this is done while the engine is still warm and involves spraying fogging oil directly into each cylinder of a four-stroke engine. If you have a two-stroke engine, instead of fogging oil you’ll use outboard oil, but the process is the same either way.

5. Check the Propeller

This is a great time to remove the propeller and check for damage. If you need to repair or replace it, you’ll have plenty of time. You should also inspect the shaft to be sure there’s nothing wrapped around it, like a monofilament fishing line. Lubricate the shaft and then reinstall the propeller.

6. Store the Motor Upright

Make sure you store the motor in an upright position. This will ensure that water drains out instead of collecting and freezing.

Now that you know how to winterize an outboard motor, be sure to repeat this process every year. If you spend some time taking care of your motor before winter arrives, you’ll be ready for the water when the sunny weather returns.

Check out all the outboard motor products available on NAPA Online, or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information about how to winterize an outboard motor, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

Photo courtesy Flickr.