Lawnmower Storage: How to Do it Right

Winter is on the horizon and it’s time to place your lawnmower into storage for the season. Follow these tips to maximize the life and performance of your lawnmower – and ensure it fires to life in the spring when you’re ready to mow grass again.

(If your lawnmower won’t start, check out this post.)

Stabilize the gas

Gasoline can break down in as few as 30 days. Oxygen, humidity, heat and other factors cause gas to change over time. Varnish, gums and other debris can form, which can clog the tiny fuel passages in the carburetor and stick the float, preventing the engine from starting in the spring.

AMSOIL Gasoline Stabilizer disrupts the chemical chain reaction that causes gas to oxidize and form varnish and gums. It keeps fuel fresh up to 12 months. As shown, it also fights corrosion and improves stability better than Sea Foam Motor Treatment.

Stabilize gas before lawnmower storage
AMSOIL improves stability.

Clean/replace the spark plug

The spark plug in a well-maintained lawnmower should last for years. Even so, check its condition for excessive deposits or wear to the electrode. Clean or replace the plug as needed.

While you’re at it, check the gap and set it to the proper size, as indicated in the owner’s manual.

Gap spark plug

Fog the engine

With the spark plug removed, spray fogging oil into the engine. It protects the cylinder, piston and valves from rust and dry-start-induced damage in the spring. Slowly pull the starter cord a few times to distribute the oil, then replace the plug.

AMSOIL Engine Fogging Oil

Remove the battery

To prevent frigid temperatures from freezing and ruining the battery, remove it and store it in a safe, climate-controlled environment. Avoid placing it next to your furnace, water heater or other mechanicals in the basement. Put it on a shelf away from open flames. Clean any deposits on the terminals.

Remove battery before lawnmower storage

Clean and protect the mower deck

Use compressed air, a putty knife, water or whatever else it takes to remove grass clippings, leaves, dirt and other debris from the engine and mower deck. Scrape the underside of the deck clean, too.

If you hate this chore, try coating the underside of the mower with AMSOIL Mudslinger. It forms a durable armor against the accumulation of grass clippings, easing clean-up.

AMSOIL Mudslinger

Sharpen the blades

Sure, this isn’t required before lawnmower storage, but it’s awfully convenient to do it now so nothing stands in the way of cutting grass come spring.

Remove the blades and sharpen them using an angle grinder or bench grinder. Replace them if they’re in bad shape.

Change the oil and filter

Used oil contains acids that can slowly rust or corrode metal components. Once rust or corrosion start, they don’t stop. Contaminants can flake off and populate the oil. When the engine is running, they scour and wear out metal parts like sandpaper.

Prior to storage, change the oil to remove acidic byproducts and ensure maximum protection against rust and corrosion throughout the winter.

Change lawnmower oil prior to storage.

Clean/change the air filter

A steady supply of clean air is just as important to engine operation and performance as high-quality fuel. Grass clippings, leaves, dirt and other contaminants can clog the air filter, causing the engine to start hard or run poorly.

Direct compressed air from the inside of the filter toward its outside to remove contaminants prior to storage. If it’s excessively dirty, replace it. The air filter is the only line of defense keeping contaminants from entering the intake and wearing out the cylinder and piston rings. It’s far less expensive to replace an air filter than an engine.

Lawnmower air filter.

Store in a dry, covered place

Once the mower is cleaned and prepared for storage, place it in a clean, dry place for the winter. Avoid storing it outside if possible. If you have no choice, secure a tarp over it so it doesn’t blow loose. Don’t be that person who covers the engine with an upside-down bucket and shoves the mower alongside the house for the winter.

Follow these lawnmower storage tips and your mower should start right up in the spring and last for years.


  1. Would like to add to the “change the oil and filter”. After changing the oil start and run the engine for 5 minutes. This pushes out the layer of old oil coating the crankshaft & bearings, piston & rings, camshaft etc. This way the entire engine’s internal parts are coated in new oil and it will circulate the fuel additives throughout the entire fuel system for winter protection.

    1. Good idea, Joe. Thanks.

      I run stabilizer all year, so treated gasoline is always dispersed throughout the system. Good call on running the engine to distribute the oil.



    2. Hello John,

      You didn’t mention that you run stabilizer all year in your fuel, that’s why I mentioned running the engine for people that don’t use it all year round. Also, instead of running fuel stabilizer all year long why not run AMSOIL Quickshot at the rate for maintaining fuel systems? It cleans the entire fuel system, valves, controls ethanol and has stabilizer for short term. I put stabilizer in my gas cans that sit for 6 months for my generator, but my gas cans for my lawnmower and two-cycle mix are empty within two months, so I use the Quickshot in them. The bowls on all my carburetors are like brand new and I have carburetors that are 20 years old without a rebuild.

    3. Hi Joe,

      I run Quickshot all the time, too. Yes, it’s overkill, but I do it because I never know how long fuel will sit in a piece of equipment. If I use only Quickshot, it’s possible I will fill the gas tanks on my snowblowers in March, but not use all the gasoline in the tanks until the following fall if we don’t get much snow in the spring. To play it safe, I use Quickshot and Stabilizer all the time.



  2. Thanks for the information, Really useful to know about all these lawnmower tips in a single place. Also shared with my colleagues.

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