How to Winterize Outboard Boat Motors

A properly winterized motor will weather the winter well.

As fall passes and you haul your boat out of the water for the last time this season, you need to prepare your outboard motor for winter. This process, called "winterization," has two goals: preventing damage to your motor's cooling system that results from freezing and thawing, and preventing corrosion in critical areas like the cylinders and the carburetor. A properly winterized motor will start with a minimum of effort at the beginning of the next boating season.

Things You'll Need

• Pliers
• Propeller wrench
• Adjustable wrench
• Garden hose
• Flushing attachment
• Fogging oil

Instructions

1. Remove the propeller according to the instructions in your owner's manual. You'll need to use a pair of pliers to pull the cotter pin through the propeller nut, or to bend the tabs on the retaining washer, depending on which arrangement is used to keep the nut in place. A propeller wrench is a good investment, but an adjustable wrench works as well.

2. Connect a garden hose to the flushing attachment (often referred to as "ear muffs"). Slip the ear muffs over the water intakes on your outboard and turn the hose on "full force." Start your motor.

3. Remove the fuel line from the carburetor. This may be as simple as pulling on the line, but more often you'll need to use a pair of pliers to release a clip that holds the line in place. Have your can of fogging oil handy and, as soon as you disconnect the fuel line, spray fogging oil into the carburetor. When the engine shuts down from lack of fuel, turn off the hose and remove the ear muffs.

4. Remove the spark plugs and spray fogging oil into the cylinders. Install new spark plugs.

5. Drain the lubricant from your motor's gear case and refill it with fresh lubricant. The exact procedure is detailed in your motor operator's manual.

6. Open all the cooling system drain plugs on your motor (their locations are marked in your service manual) and leave them open. Reinstall the propeller.

7. Store the motor upright (in the operating position), preferably in a place that isn't subject to freezing and thawing.

Tips & Warnings

• Put fuel stabilizer in your boat's gas tank before starting your engine to winterize your motor. The stabilizer will keep any fuel left in the tank from separating and causing problems at the beginning of the next boating season.

• Removing the propeller before winterizing the motor may seem like an extra, unnecessary step, but propeller-strike injuries can be every bit as serious--or even fatal--to people as they can to marine life.

References

• BoatUS: Winterizing Your Engine

Resources

• Read this Article in Spanish