How to Winterize Your Lawn Mower

Winterization is the single most important maintenance task you perform on your mower to ensure it fires up on the first pull next spring. Letting fuel sit in the tank all winter leads to gummed-up carburetors and degraded fuel lines, which are expensive repairs that could have been avoided with ten minutes of preparation. Done well, this process seals the engine against moisture and keeps the cutting deck from rusting out while the machine sits idle in a cold garage or shed. Treat this as a seasonal closing ceremony for your lawn equipment; it is the difference between a pristine start in March and a trip to the small engine repair shop.

  1. Empty the fuel system first. Run the mower until it dies to empty the carburetor bowl, or use a siphon pump to remove all gas from the tank. If you prefer not to drain it, add a fuel stabilizer to a full tank and run the engine for five minutes to ensure the treated fuel reaches the carburetor.
  2. Swap old oil for fresh. Warm the engine for a few minutes to thin the oil, then place a catch pan under the drain plug. Tilt the mower (air filter side up) to drain the old oil, replace the plug, and refill with the manufacturer-recommended oil weight.
  3. Scrape the hidden rust factory. Scrape away dried grass clippings and dirt stuck to the underside of the deck using a putty knife or stiff wire brush. Use a garden hose to rinse the underside, but be careful not to spray water directly into the air intake or carburetor.
  4. Check blade for damage. Check the cutting blade for deep nicks, cracks, or extreme dullness. Remove the blade using a socket wrench if it needs sharpening, or simply file away burrs with a metal file if it is in relatively good shape.
  5. Replace filters for spring readiness. Remove the air filter and replace it if it is paper, or clean it with soap and water if it is foam. Disconnect the spark plug wire and replace the plug if it looks fouled or carbon-heavy.
  6. Tuck it away properly. Move the mower to a cool, dry place like a shed or garage. Cover it with a breathable tarp or mower cover to prevent dust buildup while allowing moisture to escape.