How to Winterize Your Lawn Mower

If you don't feel like unneccessarily shelling out big bucks next year to repair your mower when it was running just fine this year, there are a few preventive measures you can take now.

Here are nine simple steps to winterizing a lawn mower now so it won’t be an issue in a few months.

Time needed: 2 hours

Total Cost: USD 35

Things Needed

1. Change the Oil

   Properly check the oil level, adding a little if needed. Then warm the engine for 5-10 minutes before draining all the old oil from the mower engine. Replace the oil with the specific type/weight recommended by the manufacturer. Recycle the old oil at a local transfer station, car-repair shop, or auto-parts store.

2. Remove or Stabilize the Fuel

   A mower used at the end of the season needs to be emptied of fuel. This is the single biggest step to ensure your mower starts in the spring. First, drain or siphon the gas tank dry. If the gasoline has a fuel preservative, you can save it until next spring or run it in your snow blower. If the gasoline has not had a preservative added, you need to use up the gasoline as soon as possible. Allowing it to sit over the winter will cause the ethanol in the gasoline to separate and its other chemical components to degrade.
   The alcohol in the fuel dissolves plastic and rubber parts in the fuel system. It also gums up carburetors and attracts moisture, which corrodes metal parts. And even if the engine escapes damage, it experiences a loss of performance from chemically degraded fuel because ethanol-based gasoline can spoil rapidly, often separating into layers of alcohol and fuel.
   Once you’ve emptied as much gas as possible, start the mower and run it dry, burning through any remaining gas. If the fuel lines are easily accessible, you can disconnect and drain them, too, to ensure that the mower is as fuel-free over the winter as possible.

3. Remove the Battery

   If you own a lawn tractor, remove its battery and bring it indoors for the winter if possible, or make sure the battery is fully charged and just disconnect the negative battery cable. You can maintain the battery by installing a Battery-Minder or other smart battery trickle-charger. Clean the battery well, removing any dust, grease, dirt or corrosion on the terminals. Store it in a cool, dry location away from flammable substances like gasoline or heat sources like a water heater or furnace. Come next spring, use a 12-volt battery charger to bring the battery to full capacity, then reinstall it into the mower.
   Same goes for a cordless, battery-powered mower: remove the battery and store it indoors.

4. Remove the Spark Plug

   Remove the spark plug and spray a shot of fogging oil into the cylinder. Pull the recoil handle several times to ensure that the oil is evenly distributed on the wall of the cylinder. Replace the old spark plug with a new one.

5. Replace or Clean Filters

   Remove and clean or replace the mower’s air filter and fuel filter. Check the owner’s manual for more specific maintenance information.

6. Clean the Mowing Deck

   Remove the spark plug to prevent accidental starting, then tip the mower onto its side(if a push mower, making sure dipstick-side is down, air filter side is up), or prop it up securely on ramps or jack-stands. Unbolt and remove the mower’s blades. Next, use a putty knife to scrape loose any caked-on grass clippings from the underside of the deck. (Grass clippings contain moisture that can cause rust.) Then, spray on a liberal coating of WD-40.

7. Sharpen the Blades
   

   To ensure your mower cuts evenly and cleanly, it’s important to sharpen the blades at least once a year. However, if the blades are bent, chipped or cracked, replace them with new Oregon Gator Blades. And don’t forget to balance the blades before reinstalling them. For specific instructions on sharpening lawnmower blades, Popular Mechanic's explainer has you covered. Caution: Before removing the mower blades, first take out the spark plug to prevent accidental starting.

8. Clean and Lube the Mower

   Before putting the mower away for the season, blow off or brush away any large debris sticking to the mower. Use a damp cloth to wipe down the engine housing, wheels, handle, and top of the mowing deck. Lubricate all exposed cable-movement points and pivot points using a good-quality spray lubricant.

9. Storage Tips

   Store the mower indoors, if at all possible, and under a tarp to keep off the dust. If mice are a problem, place tamper-resistant, pet-safe bait stations under the mower. That will discourage mice from climbing into the engine and chewing up the electrical wiring. If you have to keep your equipment outside, keep under a rain-proof tarp and solid, dry ground to prevent rust from forming on the deck.

10. Don't feel like doing any of this? Check out Mobile Small Engine Lawn Mower Repair Tune-Up Service. Schedule our Services, FAQ, How We Operate