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

If you don’t properly winterize your motor, rust or corrosion may damage it. You can greatly extend the life of your outboard motor by winterizing it every year. 

How to Winterize Your Outboard Motor: A Step-by-Step Guide 1

How do you winterize an outboard motor?

To winterize a motor, you need to remove all of the old grease and oil and replace it. You need to clean everything properly and lubricate all the moving parts. You also need to use fogging oil to prevent the motor from rusting/corroding over the winter. 

I live in the northern US and I always winterize my outboard motors. It does not take long and it greatly extends the life of these machines. You might have to buy a few tools, such as a wrench for the oil filter, but the tools are cheap.  

What is Winterizing a Motor?

Winterizing a motor is preparing it for winter storage. It is bad for your engine to store it until the next boating season without winterizing it first. 

Winterizing the motor involves protecting it from damage due to freezing. If there is water in a motor, that might freeze during the winter and cause problems. You also need to prevent corrosion.

How Important is Winterizing Your Motor?

Winterizing your boat motor is an essential form of engine maintenance. If you don’t winterize your engine, it could cause significant damage. Don’t wreck your outboard motors by neglecting to get them ready for winter storage.  

Winterizing a boat motor protects it from freezing and corrosion. With a bit of preparation, your motor can withstand the harsh winter elements and be as good as before when spring weather comes along. Failing to winterize it won’t necessarily destroy it, but it is at least excessive wear on your engine. 

Keeping your boat in your garage and wondering if you still need to winterize it? Check out our guide!

Do All Outboard Boat Motors Require This?

Yes, you almost certainly have to winterize your outboard motor. A boat motor is not designed to be left unused for the whole winter with old fuel in it and saltwater all over it. 

How to Winterize Your Outboard Motor: A Step-by-Step Guide 2

Steps to Winterize an Outboard

Clean it With Water

First, you need to flush the engine with water, which has to be fresh water. If you don’t have a flusher, running the engine in a tank full of clean water is enough. 

Clean all of the dirt and dust off of the outside of your motor and clean the powerhead. Cleaning everything properly is a crucial part of the winterization process. 

Fill the Oil Tank and Change the Oil Filter

Fill the tank with oil, and use the first type the owner’s manual suggests. Change the oil filter. Old filters and old oil should not be left over the winter. 

Spray Fogging Oil On the Gear Case

First, open up the gear case and change the oil. Inspect the drain plugs and see if any of the seals are damaged and need to be replaced. 

Spray fogging oil directly on the gear case. This is to prevent rust from damaging these 

components during the winter. Efi fogging oil is one of the better brands. 

Drain the Fuel Filter

You don’t necessarily need a new filter. However, you need to drain the fuel from it and replace it with new fuel before putting your motor in storage.

Sometimes, an outboard motor has a fuel water separator filter, which needs to be replaced. If there is a carburetor or vapor separator tank, drain it. 

Lubricate All the Parts

You also need to grease many parts before you can store your engine safely. You need to lubricate the motor (make sure you reach every pivot point and every seal) and the propeller shaft. Lubricating the prop shaft on outboard engines is an essential step some people foolishly skip.

Finally, apply fogging oil to the motor’s rubber parts and to the powerhead. As long as you completed every step, your motor should now be ready for storage. Store your engine somewhere where there isn’t much moisture, and cover the engine. 

How to Winterize Your Outboard Motor: A Step-by-Step Guide 3

What Tools Do You Need?

You should at least have needle nose pliers and an oil filter wrench. You might also want a grease gun, garden hose, and gear lube pump.

Do You Need a Flush Muff Device?

Using a flush muff device to flush your engine with water is a good idea. It’s much easier than filling up a tank with a hose. Flush muffs are cheap devices that connect to your garden hose. 

What is a Corrosion Inhibitor?

A corrosion inhibitor or corrosion guard is a liquid that dries to a waxy film and keeps water out to prevent rusting. Using an inhibitor every time you winterize your engine will extend its life. Fogging oil is a corrosion inhibitor. 

What is a Yamalube Fuel Stabilizer?

Yamalube fuel stabilizer lets you store your motor in the winter without draining the fuel out. Fuel stabilizer prevents gum and varnish from building up in your engine. Treated fuel last a lot longer than regular fuel, but it doesn’t last forever. 

It can keep your fuel fresh for 12 months or 24 months. Some people use fuel stabilizers regularly. They add a bit of fuel stabilizer every time they add fuel because this may lengthen the equipment’s life. 

Winterization Tips and Tricks

How to Winterize Your Outboard Motor: A Step-by-Step Guide 4

It is particularly important to wash and flush everything with fresh water if you use your boat motor in the sea or a saltwater lake. The saltwater can corrode metal parts including your two or four-stroke outboard motor. 

Consider using a gear lube pump even if it isn’t quite necessary. A gear lube pump makes it easier to lubricate the steering column and every other part of your motor. 

Use New Grease and Oil

Always use fresh grease, fresh gas, and fresh oil. If any of the old outboard oil is left, there might be contamination with moisture. You can also foul the spark plugs if you don’t add new motor oil. 

If you have a portable fuel tank, make sure you add new fuel to it and add a stabilizer. Don’t use gas that contains ethanol when you winterize the tank. Don’t forget to change the oil in the outboard lower unit. Add new gear oil and new crankcase oil. 

Is This a Job for a Professional?

No, if you like to do things yourself, you can winterize a motor yourself. It is not a skilled or complicated job where you can easily damage your motor by doing something wrong. 

The main thing is to make sure you complete the winterization process. If you put your motor away even though it has not been winterized properly, that might damage your entire engine. 

Make sure that what you are doing is right for the specific engine you have. Look through the owner’s manual and proceed carefully. There may be freeze damage if you do the job improperly. 

Key Takeaways

  • You can also use a fuel stabilizer to get your fuel system ready for winter storage. 
  • Stabilized fuel will last for a year or two in your engine. 
  • At worst, not winterizing your boat can damage your entire fuel system.
  • Spraying fogging oil inside your engine is also necessary. 
  • Look through the owner’s manual and make sure everything gets done right.