As winter approaches, it reminds us that it is time to winterize our air cooled gasoline-powered lawn mowers . Winterizing will help extend the life of our lawn mowers. This post is for air cooled engines only. There is a lot of steps that are the same for liquid cooled engines but there is also a lot of steps that are not covered here. My next post will be for liquid cooled mowers.

The first thing I like to do is put a mixture of Fuel Stabilizer an gas in the fuel tank. Do not fill tank full, I will only put a small amount of this mixture in the tank. (We will come back to the fuel system later in this post).


Next Step: blow(with compressed air) or wipe the mower off, removing sticks, grass clippings an so on. The deck should be washed with soap and water and a stiff bristle brush, then blow the water off with compressed air. Spray the underside of the deck with W-D 40 or some other rust preventer. Clean the outside of the engine making sure to blow the air vanes that keep your air cooled engine cool. Do this with compressed air making sure to blow all debris from the air vanes.
You can wash the whole mower if you want, just be sure to dry it off as much as possible. Where I work at I washer all of our mowers with an agent called Luster. Luster has the washing detergent and polish mixed together.

Next Step: grease all grease fittings(Zerk Fittings) and a little 3 in-one oil on contact points that slide like hood hinges and etc.

Next Step: drain the crank case oil and refill with new oil. If it has a filter change the filter also. We do this to remove all the contaminants from the crank case, which could damage the internal engine parts from setting idle over the winter. If the engine has a foam air filter you can wash it with soap and water. You can dry the air filter by putting it in a clean dry towel and squeezing it dry with your hand.
Most all foam filters have to be oiled, you do this by putting a little pre-oil or 30 w motor oil on the filter an lightly work the oil through the filter. I usually put the filter back into a clean towel after putting oil on it and lightly squeeze to remove any excess oil from the filter. If your mower has a paper element filter then just put it back in for now.


Next Step: Start the mower and let it run. This will let the fuel stabilizer we put in the tank distribute through the fuel lines and the carburetor.
Make sure the mower is in a safe place with the deck up (if possible)engage the cutting blades to distribute the grease we put on the spindle bearings(grease fittings) in early steps.
Yes, we are getting close to being done so stay with me.

Next Step: In the earlier steps we put fuel stabilizer in the tank, now if your fuel tank is easy to remove, do so. Pour the gas out of tank into a clean approved container. If you can,t remove the tank try to siphon the gas from the tank into a clean approved container.

Next Step: Restart the mower and let it run until the engine goes dead or stalls.
If the tank is difficult to remove or siphon from, then fill the tank completely with the fuel/stabilizer mixture. (By filling the tank to the full level you are eliminating the air space that causes moisture).
You can remove the spark plug and add a little oil through the plug hole(about 50ml) to the cylinder and spin the engine over. I like to spin the engine over by hand or the crank rope if possible. If the mower has a electric starter just use it it briefly spin the engine over. This lubricates the cylinder wall to prevent it from rusting.

Next Step: Fill up the tires with air and store your mower in a dry place away from the weather.
Neglecting to empty the gas tank and perform other end-of-season care can shorten your mower’s life considerably, and can lead to costly repairs.

When grass cutting time gets close next spring, I will have a post telling you how to get your air cooled mower ready to mow.