How to Winterize a Lawn Mower

If your lawn mower won’t start after winter, it could very well be because you missed one of the critical steps listed below. Follow these tips to winterize your lawn mower and you’re far less likely to be dealing with a lawn mower that won’t start after winter ends!

Clean the Undercarriage

There’s a good chance that your mower’s undercarriage is covered in caked-on grass, dirt and leaves after a summer’s worth of lawns mowed. It’s best to clean all that gunk out of there before letting it sit for an entire winter. Use a dull chisel or some other scraping tool to remove dirt and debris from the undercarriage. If you’ve got some particularly stubborn dirt trapped under the mower deck, hitting it with a low-level spray from a pressure washer should loosen it up.

Change the Oil

Old oil contains gasoline, moisture, soot and acids that can corrode internal engine components over the winter. Change the oil in your mower and run it for a few minutes to coat all the internal parts with clean oil. Make sure to use the right type of lawn mower oil for optimal performance.

Should You Leave Gas In the Tank?

If there’s still gasoline left over after you winterize your lawn mower, it could end up corroding the carburetor and clogging the fuel system. Remember to check out our tips for how to tune up a lawn mower for spring! Lawn mower manufacturers, like Honda and John Deere, recommend different ways to store their products: completely draining the gas or filling it with fresh, stabilized gasoline. Refer to your owner’s manual to learn which method is best for your particular engine.

Find out why Honda has announced that it will stop manufacturing gas-powered lawn mower motors.

How To Empty a Lawn Mower Gas Tank

Drain the fuel tank by removing the fuel tank cap and tipping the mower over a drain pan. Next, look for a drain valve or bolt on the carburetor bowl. Open the valve or remove the bolt and drain the gas into a container. If your carburetor doesn’t have a drain valve or bolt, run the engine until it stalls. Then pull the starter rope or operate the electric starter to restart the engine several more times. When it will no longer start, it’s ready for storage. Take the old gas to your local recycling facility.

How To Add Fresh Stabilized Fuel

If the owner’s manual recommends storing your lawnmower with a full tank of freshly stabilized gas, follow this procedure. Empty the old gas following the instructions above. Add fuel stabilizer to an empty gas can. Then fill the gas can with fresh gas at the pump. That’ll thoroughly mix the stabilizer with the new fuel. Fill the mower tank with fresh gas and screw on the gas cap. Run the mower for 10-min. to fill the carburetor bowl with stabilized gas. Top off the gas tank and store the mower.

NOTE: Never add fuel stabilizer to old gas—it won’t bring it back to life. It must be added to fresh gas.