How to Store Your Lawnmower in Winter

Proper storage ensures your lawn equipment will run well for years.

September 26, 2023

Winter is on the horizon and it’s time to store your lawnmower and other lawn and garden equipment through the colder months. The following tips will help you maximize the life and performance of your lawnmower and ensure it springs quickly to life when you’re ready to mow grass again.

Stabilize the gas

Without a stabilizer 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 may form, which can clog the tiny passages in fuel lines and injectors or stick the floats in carburetors, 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*.

Clean or replace the spark plugs

The spark plugs in a well-maintained lawnmower should last for years. Even so, check the condition for excessive deposits or wear to the electrodes. Clean on a wire brush (bench grinder is what I use) or replace any dirty plugs as needed. While you’re at it, check the gaps and set them to the proper size, as indicated in the owner’s manual.

Fog Spray 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.

Remove the battery

You know, people don’t maintain batteries like they used to.. 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.

Damaged and corroded car battery danger

Clean and protect the mower deck

Use compressed air, a putty knife, water and AMSOIL Heavy Duty Degreaser to remove grass clippings, leaves, dirt and other caked-on debris from the engine and mower deck. Don’t forget to clean the underside of the deck, too.

Let me tell you something, If you prefer to ease the pain of doing this dirty work again next year, try coating the underside of the mower with AMSOIL Mudslinger. It forms a durable armor against the accumulation of grass clippings, making cleanup easier.

Change the oil and filter

Too many people let the mower go another year without changing the oil.. Don’t do that! 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 like sandpaper and wear out metal parts. Prior to storage, change the oil to remove acidic byproducts and ensure maximum protection against rust and corrosion throughout the winter.

Clean or 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, replacing it is cheap insurance. 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. Heck I always vacuum mine and it lasts for years. I used to buy them cheap at Kmart. Wish we still had our Kmart around..

Sharpen the blades

This isn’t required before lawnmower storage, but it’s more convenient to do it now, so nothing prevents a quick mow when that first sunny and dry spring day finally arrives. Remove the blades and sharpen them using an angle or bench grinder, but don’t hesitate to replace them if they’re in bad shape. I’ll tell you what, look for a good mower shop (dont tell him you use AMSOIL as he’ll know you never need repairs, lol) and see if they do blade sharpening. Proper sharpening in a jig makes a huge difference especially in a mulching mower.

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, but if you have no choice, secure a tarp over mechanical equipment to help protect sensitive components from the elements.

Following these simple lawnmower storage and maintenance tips will ensure your mower starts right up in the spring and continues to provide excellent service for many years.

We also have some advice for when your lawnmower won’t start, and if you prefer videos, we’ve got that too:

Engine start-stop technology can increase bearing wear

Use only the best quality oil in these engines as the crankshaft needs to float. Even the “so called synthetics” don’t dampen the metal to metal issues mentioned below nearly as well as AMSOIL and you can tell due to the reduction in vibration or more consistent oil pressure as you rack up miles.

Yet another reason to upgrade to AMSOIL synthetic motor oil.

Matt Erickson | DIRECTOR, TECHNICAL PRODUCT MANAGEMENT

Nearly every technology shaping the auto industry can be traced to one goal: increased fuel economy. Engine start-stop technology is one more tool automakers have in their arsenals to ensure today’s vehicles meet tomorrow’s tightening fuel-economy regulations.

In principle, start-stop technology is simple: the engine automatically shuts off while you’re idling and restarts when you take your foot off the brake. This reduces fuel wasted while idling. Automakers introduced different startstop systems in the late ‘70s and early ‘80s; however, drivers found them awkward and unworthy of the higher vehicle price. Today’s start-stop systems are less obtrusive and are available on vehicle models from most automakers.

Should be called Metal to Metal Contact Engine

That’s not to say they’re without detractors. In fact, some automakers have installed off switches that allow motorists to disable the feature in response to negative driver feedback. But, despite their pitfalls, they’re likely not going anywhere. Consider these statistics:

According to bearing manufacturer MAHLE*, U.S. vehicles burned 3.9 billion gallons of gasoline while idling in 2017.
Buick* reports that engines with start-stop technology increase fuel economy 4-5 percent using the EPA test cycle.

Automakers leap for joy over minuscule fuel-economy gains, so you can bet they’re going to stick with anything that may provide a 4-5 percent boost.

So, what does that have to do with motor oil?

Maybe you’re aware that most engine wear occurs during cold starts. Well, engine wear occurs during warm starts, too, like every time an engine equipped with start-stop technology restarts.

We have to get technical to understand why.

The crankshaft spins thousands of times per minute in a running engine. As it spins, oil flows through tiny openings in the crankshaft journals and fills the spaces between the journals and main bearings. The crankshaft literally floats on an oil film and doesn’t contact the bearings. We call this scenario hydrodynamic lubrication. In this regime, the bearings suffer little wear and last a long time.

Run of the mill oils (95% on the shelf) are not going to provide protection with this condition

Stopping the engine, however, reduces oil film thickness. The crankshaft settles onto the bearing surfaces rather than floats over them. The oil film thickness shrinks to about the same thickness as the surface roughness of the crankshaft. This is called boundary lubrication. Starting the engine allows the microscopic peaks on the metal surfaces to contact and cause wear until the oil film has been reestablished and the crankshaft is once again floating over the bearings. This is where the oil’s additives play a huge role in protection.

Granted, only minimal wear may occur each time the engine is started. It’s not a big concern in a properly maintained traditional engine using a good oil. But what if you greatly increase engine startstop cycles?

Consider another statistic from MAHLE:

Start-stop cycles in equipped engines may triple over the engine’s lifetime compared to traditional engines.

That means three times more engine starts, three times more instances of boundary lubrication and three times more exposure to increased bearing wear.

Bearing wear can snowball out of control, too. Metal particles can break off and populate the oil. The bearing surface becomes rougher, encouraging adhesive wear in which peaks on metal surfaces grab and tear the mating surfaces. Eventually the crank journal and bearing can weld together, ruining the bearing.

This all points to a simple directive: make sure your customers with engines using start-stop technology are using AMSOIL synthetic motor oil to guard against bearing wear. Oil film thickness shrinks when engines start from a dead stop, placing even more importance on oil additives to maintain protection. Since engines equipped with start-stop technology spend so much more time under boundary lubrication, it’s vital to use an oil with superior film strength and additive quality. AMSOIL Signature Series Synthetic Motor Oil delivers. It provides 75% more engine protection against horsepower loss and wear** to help protect today’s advanced engines.

This is especially needed in vehicles calling for 0W-20, 5W-20 and 0W-16.

Tag: floats