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How to Winterize a Lawn Mower

How to Winterize a Lawn Mower

Ready or not, the seasons are changing. Dropping temperatures and color-changing leaves usher in the colder months of the year. Taking some time now to do some basic lawn mower maintenance can help save you time and frustration at the start of the next mowing season.

With all the wear and tear from continuous summer use, most lawn mowers typically need maintenance at the end of the season to remain in good working condition for the long term. And while it may seem harmless to place your mower straight into the shed until next spring, neglecting proper winterizing of equipment can not only double the work for next spring, it also can impede the overall performance of your mower. If the maintenance work is taken care of at the end of the mowing season, your equipment should be ready to go for the first cut next spring.

The following are general tips on winterizing a walk-behind mower and can help you prepare for the cold months ahead. Depending on your model, the instructions listed below may vary slightly. Always be sure to check your operator’s manual for detailed instructions before storing your lawn mower for winter.

End-of-Season Walk-Behind Mower Maintenance

Step 1 – Gather Needed Tools and Supplies

Most winterizing procedures listed below can be completed with a basic mechanic’s toolkit, but some steps may be much easier when utilizing the Siphon Pump, Blade Sharpening Kit and Blade Removal Tool, available through the links in this article.

Step 2 – Pre-Prep: Check and Replace Spark Plugs.

Before you check the spark plug, be sure the mower is on a flat, level surface. Turn the engine off and make sure it is cool. Disconnect the spark plug ignition wire. Replace worn or damaged spark plugs. Check the old spark plug or your mower’s operator’s manual for the correct part number.

Step 3 – Change the Oil.

Knowing how to change the oil on a walk-behind mower is an important step in winterizing your equipment for storage. Remove the dipstick. Then, using a siphon pump, place the top tube into the dipstick hole on the engine and the bottom tube into the oil pan. Prime the pump by pumping the handle three to four times. Once the oil begins to flow, it will flow without further pumping. When the oil has drained, remove the siphon pump. Add new oil as instructed in your mower’s operator’s manual. Replace the dipstick. Wait several minutes, then use the dipstick to check the oil level.

Step 4 – Replace and Clean the Air Filter.

Air filter covers are typically removed by pressing on tabs to release the cover, allowing you to remove the cover and remove the old air filter. Replace with a new filter and reattach the cover to secure it to the mower.

Step 5 – Clean and Inspect the Mower. Replace the Mower Blade.

Give your lawn mower a good, thorough cleaning. Brush off leaves, grass, dirt and mud from the outside to avoid buildup and molding over the winter. Also, remember to check under the deck of your mower for hidden accumulation by tilting the mower on its side with the air filter facing up. Clean the undercarriage of dirt, grass clippings, and other objects that may be lodged there. If your mower is equipped with a deck wash port, you can connect a standard garden hose to help flush out debris. Too much debris beneath the deck can lead to an overheated engine, which can trigger corrosion and rust if it’s not cleaned properly and quickly.

Before you start changing the blade on your walk-behind mower, begin by wearing gloves and inspecting the blade for wear or damage. Use the Blade Removal Tool to hold the blade in place. Then, using a socket, loosen the bolt securing the cutting blade to the engine drive shaft. Remove the blade.

Before selecting a new blade, check the center hold pattern of the existing blade and purchase a new blade with the same pattern. (Learn more about different blade types here). Assemble the new blade and blade adaptor on the engine crankshaft and tighten the bolt to the proper torque as indicated in your operator’s manual. If your blade only needs sharpening, use the Blade Sharpener and Balancer Kit or take it to a servicing dealer for assistance.

Step 6 – Check the Mower for Any Other Broken, Worn or Missing Parts.

Check the mower for any other broken or worn parts, including the belt cover, belts, discharge chute, bag, mulch plug and tires. Replace any of these worn or broken parts with the correct replacement parts as noted in your mower’s operator’s manual.

Step 7 - Prepare the Fuel Tank, Engine and Mower for Storage.

Prevent Rust

Rust on the lawn mower can obstruct operation and may lead to long-term structural and performance issues. To help keep the lawn mower deck from rusting, use a light oil or silicone to coat the equipment, such as cables and other moving parts of your mower, before storage. This can help provide a fresh cut come spring.

Engine Care

Is your mower going to be stored for at least 30 to 90 days this winter? If so, fill the tank with fuel and treat it with a gasoline stabilizer, such as STA-BIL® Fuel Stabilizer, to help prevent deterioration. A full fuel tank helps prevent moisture, rust and carburetor clogging. Use a stiff bristle brush and rag to clean the engine exterior to allow proper air circulation while it is in storage. Also, remove all grass, dirt and combustible debris from the muffler area to help ensure your machine is ready to use on the first day of spring.

So while you might be tempted to simply put your mower away after the last use and not think about it for a few months, maintaining it at the end of the season can help to keep your mower in optimal condition so that it can run smoothly next spring. Get a jump on next season by reading how to start a lawn mower after winter storage.