How to Winterize a Boat Motor

Lead Image for How to Winterize a Boat Motor
  • 2-6 hours
  • Intermediate
  • 25-75
What You'll Need
Garden hose
Fuel stabilizer
Fogging oil
Flushing kit

Many people are not aware of the proper procedure for winterizing a boat motor and do not do a thorough job when getting their boat ready for cold weather. Many people hesitate because they do not want to spend a lot of money on something that is going into storage for several months, but winterizing your boat motor is one of the most important things that you can do as a boat owner. If your boat is going to be subjected to cold temperatures, it needs to be winterized properly in order to prevent serious damage and expensive repairs come warm weather seasons.

Step 1 - Check Condition of Wires and Hoses

The first thing that you should do is pull the engine cover and make sure everything appears to be in good working order. Ensure that there are no wires coming loose. Check the hoses for signs of cracks or weakness. If there are any problems, you should make any fixes and replacements now.

Step 2 - Flush the Engine With Water

Through a lot of use, your engine can get built up with a lot of things that do not belong in there. You need to flush the engine with fresh water and make sure that you get rid of any buildup inside. Many engines actually have a place for a hose to hook up to in order to perform this task. Hook up the hose and let the water run through for as long as you feel appropriate for your level of buildup. When you are done with this step, make sure that you position the motor so that it can drain properly. Any water that remains in the motor could freeze and cause major problems over the winter. As you flush the engine, you should collect the water in a bucket and dispose of it properly. There may be an area at your marina or dock to dispose of it.

Step 3 - Flush the Cooling System

You also need to flush out the cooling system in the motor. Use a flushing kit for this step. Flushing out the cooling system will help prevent any freezing damage in the cold temperatures as well. When you are done with this, put fresh antifreeze into the lines.

Step 4 - Use Fuel Stabilizer

Refill your gas tank and pour some fuel stabilizer into the gas tank and then turn on the engine. Let the engine idle for 10 to 15 minutes while the treated fuel cycles throughout the engine. Fuel will break down while the boat sits in storage, but fuel stabilizer will keep everything in working order while it sits.

Step 5 - Use Fogging Oil

Spray fogging oil into the carburetor while it is running. Then, turn the engine off and, once it has cooled, take out the spark plugs and spray some fogging oil into the cylinders as well. Fogging oil keeps everything from forming rust and corroding during long periods of inactivity.

Step 6 - Change the Oil

Now is also a good time to change out the old oil and replace the oil filter. This will help everything run smoothly when you try to start the engine again.

Step 7 - Cover the Boat

Making sure your boat is covered with the appropriate cover will also help the motor significantly. You want it tight enough so moisture can not get into the motor during the winter.