Eazy Winterizing of 2 Stroke Outboard Boats

By Nick Ferrara

As the cool weather moves in and the thoughts of getting that last Striped Bass or Tog are in your mind. Also is the dreaded thought of winterizing your boat & motor.

Just thinking of ending your fishing season is bad enough, but the thought of more expenses from winterizing your boat will give you cabin fever early in the fall & winter months. When in truth it really isn't that bad. Many boat owners plan on spending a lot of money to have their outboard motor winterized when it is very simple to do, as well as inexpensive. Not much time is needed and it can save you a lot of money as well. Following these steps you should be finished in 1 hour.

I have put together a list of some basic, easy ways to get that boat & outboard motor ready for the cold weather.

First things that you will need from your local marina or boat supply store.

Winterizing Supplies

1 - Lower Unit Gear Lube ( 150 hp take close to 2 quarts)
2 - Fogging Oil ( 1 to 2 cans)
3 - Gasoline Additive / Stabilizer (1 fl. Oz for each 5 gallons of fuel capacity)
4 - CRC or WD - 40 (I prefer CRC)
5 - Marine Parts Grease or Lube
6 - Marine Anti - Freeze ( 1 gal. )
7 - Motor Oil (about a tablespoon)
8 - Lower Unit Gear Lube Pump w/ fitting for your engine
9 - New Fuel / Water Separator Filter

The cost of the supplies should run you about 50 dollars. Most of the products should yield enough for 2 seasons of winterizing your motor except (Gear oil, Fogging oil & Fuel / Water Separator Filter). The gear lube pump is a onetime cost and will last season after season.


1 - Screw drivers- (Large Flathead & Phillips)
2 - Oil Filter Wrench
3 - Pliers
4 - Wrench w/sockets (Spark Plug & 1)

With tools and supplies ready it should only take 1 hour to winterize that boat & outboard motor. Let's get started.

Getting the boat prepped is very easy. Just make sure all tanks are full. Top off fuel tanks and 2 stroke oil tanks or chambers. Moisture is caused by unfilled tanks and creates freezing in fuel and oil tanks. With all tanks filled to the top it is time to start our first step.

Add the Gasoline additive / stabilizer. Remember to add 1 fl. Oz for each 5 gallons of fuel capacity. Adding a little more is always better than not adding enough. Once added it will prevent the fuel from freezing or going bad during the winter months.

Our next step is to remove that old fuel / water separator filter. It is the same as changing the oil filter in your car. Once you remove the old filter it is time to get the new filter ready to install. Take the new filter and the motor oil. 10w 30 motor oil works great. Wet your finger with the oil and run your finger abound the seal.

It will help to create a vacuum seal and also help in keeping the seal from dry rot. Take the filter and install it at hand tight.

The next step is probably the worse step of them all. It is changing the lower unit gear oil. I say it is the worse because it can be messy. Not hard as it usually is just removing 2 large flat head screws from the lower end to allow the oil to drain. Have your motor lowered as far down as you can and remove both the top and bottom screws. Make sure you do not lose the gasket seals on the screws. Allow all the gear oil to drain into a pan. Once all the oil is out it is time to pump in some fresh gear oil. With both screws out connect your pump into the bottom hole of the lower end.

Pump in the gear oil until it starts to come out the top hole. Once the oil comes out the top replace and tighten the top screw. Know for the tricky part. Remove the pump carefully while sliding your finger over the hole. Hold the screw hole until you have the screw back in hand. As quickly as you can get that screw back into place without losing gear oil. Sure you will lose a small amount of oil, but if you have filled it to overflow you are fine. The reason for changing gear oil when you winterize is to remove the old worn, broke down and impure gear oil from the season. It is not good to let that old, dirty, weak, gear oil set on the gears all winter. Plus it is one less thing to do in the spring. With that done it is all down hill now. You are half way done

Remove the engine cover or top. Unscrew the covers off of the Carburetors. Hook up a water line to your engine or use muffs to get water running through the engine. Fire up the engine and let it run for a few minutes to circulate the gasoline additive / stabilizer through the new filter and into the engine. After about 5 minutes you can start to fog the engine. Pull back slightly on the throttle linkage to reeve the engine and start spaying the fogging oil into the carburetors.

Spray it in thick and white smoke will start to billow out of the engine. Let off of the throttle linkage and continue to spray. The engine will come to a stall and shut off. That is what you want. Now all the internal parts are covered in the fogging oil to prevent moisture and corrosion. Replace the carburetor covers.

Now it's time to remove the spark plugs. Remove the plugs and spray the firing pins with the fogging oil.

Before you put the plugs back in spray each chamber with fogging oil.

Spray for about 2 seconds per chamber. This helps in making sure there is no moisture in the plugs and gives a great coat of protection with the fogging oil in all of the valve chambers of the engine.

(At springtime you should always replace the old plugs. If not remove plugs and clean off the oil. Cranks the engine 3 turns with plugs out. Place plugs in, fire up engine and burn off fogging oil, shut down remove and clean plugs again or add new plugs at this time. Fogging oil will foul plugs!)

Now for the home stretch and easiest part of our winterization of our boat and engine.

This is a simple one, but can save you a lot of money. Remove the battery and place it indoors in a warm climate. Place in the basement or anywhere warm to help from it losing charge. Never place the battery on cement, as it will kill the charge and the battery. Place it on wood if storing on a cement floor.

The basics. Sure you can wash, wax and polish the rails, but lets make sure we grease and lube to prevent rust, rot and corrosion. With the pliers and 1 wrench let's pull the cotter pin on the prop and take the prop off. Grease the prop shaft with the marine grease or lube and store the prop inside.

Bag the gears from moisture with a plastic bag taped around the lower unit and gears. Grease the engine joints and tilts. Anywhere you see old grease or wear is a good start. With the greasing done let's finish and call it a day.

The engine cover is still off. So lets protect the wire and hose coverings. Take that CRC spray and give a mist to all the hoses and wire coverings in your engine. DO NOT spray contacts and connections. Replace the engine lid and continue spraying fuel lines and the prime pump ball. Spray all the battery wires and terminals. It will help from cracking, rusting or rotting from the cold weather. Spray all fittings on boat from screws to riggings, as it will help protect from rust and corrosion.

Now it is time to end the day. With the marine Anti - freeze blow some through your engine. If you use ears add some into a hose and blow it into the engine. Do the same thing with the newer engines that have a hose hook up. Most engines will drain all the water that is in them, but some engines tent to have a small pocket or ledge that will hold water. If that is the case a small amount of marine anti freeze will fill that pocket or ledge and keep it from freezing. Take the rest of the anti - freeze and pour some in the anchor storage, bait wells, sinks, and down by the bilge pump.

Any were you see water sitting is a good place to add the anti - freeze. It will prevent freezing and stress on the fiberglass of your boats haul and bilge pumps.

I hope this step by step article helps you save money and learn how easy it really is to get the boat ready for winter. If you have never winterized a boat, give it a shot. You will find out it's a breeze and helps you save tons of money.

Written By Nick Ferrara