Engine makers disagree on the first step of putting a mower away. Some manuals say to run the tank dry. Others say to fill it with fresh fuel and a stabilizer, then run the engine for a few minutes so the treated fuel reaches the carburetor. Both deal with the same problem. Untreated gas goes stale over the winter and leaves gummy deposits in the fuel system, so follow whichever your manual gives.
The rest of this list covers the deck, the blade, the oil and the battery, plus where to park the mower until spring. It is written for walk-behind gas mowers, with notes for riding and battery mowers where they differ. Do it the weekend after the last mow, while you still remember how the engine was running.
Pull the spark plug wire off before you put a hand anywhere near the blade. A pull-start engine can turn over when the blade is moved by hand. On a battery mower, take the battery pack out instead.
- Find the mower's manual, or download it using the model number — The model number is usually on a sticker on the deck or near the engine.
- Do the last mow of the season
- Deal with the fuel the way your manual says
- Either run the engine until the tank is empty
- Or fill the tank with fresh fuel and stabilizer, then run it for a few minutes — Follow the dose on the stabilizer bottle.
- Let the engine cool completely
- Disconnect the spark plug wire — Do this before any work near the blade. A battery mower has no plug wire, so take its battery out instead.
- Remove a riding or electric-start mower's battery, or the battery pack on a cordless one
- Store the battery indoors, somewhere cool and dry that does not freeze — Charge it to the level the battery maker recommends for storage.
- Check the manual for which side to tip the mower onto — Tipping it the wrong way can let oil run into the air filter and carburetor, and fuel can leak from a full tank.
- Scrape packed grass off the underside of the deck — Wet clippings left there all winter hold moisture against the metal.
- Inspect the blade for nicks, bends and cracks
- Sharpen and balance the blade, or replace it — A bent or cracked blade gets replaced, not sharpened.
- Change the engine oil on a four-stroke mower — Use the oil type and amount the manual gives, and take the old oil to a recycling drop-off.
- Clean or replace the air filter
- Check the spark plug and replace it if it is worn or fouled
- Check the drive belt and control cables on a self-propelled or riding mower
- Lubricate the points the manual lists
- Wipe down the outside and empty the grass bag — Let the bag dry before storing it.
- Store the mower in a dry shed or garage
- Keep it away from furnaces, water heaters and anything with a pilot light — Fuel vapor from the tank can ignite.
- Cover it with a breathable cover or an old sheet
- Use up or stabilize the fuel in your gas can, and date the can — Keep gas cans in a shed or detached garage, never in the living space of the house.
- Write down any parts to order before spring
- Reconnect the spark plug wire and use fresh fuel at the first spring mow