My brother-in-law is a farmer and has kept his John Deere lawn tractor looking like new for many years. He says part of that is winterizing it properly. So what steps should we take to do this?

To winterize a John Deere lawn tractor you’ll need to clean it, empty the fuel tank, take out the spark plugs and battery, then store it under a tarp inside in a dry shed or garage with the parking brake on. Place some mouse repellant nearby so rodents don’t chew the wiring over the winter.

Let’s dive down into a step-by-step guide on how to winterize your John Deere lawn tractor, then we’ll include an FAQ on all your most important questions about the process…

Winterizing Your John Deere Lawn Tractor (Step By Step)

We looked for easy-to-follow videos on how to winterize a series-100 John Deere lawn tractor. The best video we found is linked below. 

Things you’ll need:

1. STA-BIL Fogging Oil. You can find it on Amazon or at a car parts store.
2. TRUFUEL Engineered fuel. This is a non-ethanol gasoline. Be sure to buy the 4 cycle version.
3. Socket wrenches.
4. Pair of pliers. 
5. Gasoline funnel.
6. Gas can. It should have a cap that closes tightly and a pouring spout.
7. Hand siphon. You can get a cheap ($10) hand siphon at Walmart, most car parts stores and some hardware stores. There’s a photo of one in the linked siphoning video below.
8. Battery charger. Also available at car parts stores, Walmart and Target.

Here are the steps to winterize your mower:

• If you haven’t performed a machine clean-out and you service your own engine, consider giving your mower some TLC before winter. Start on page 28 in the operator’s manual linked below for the service intervals, the list of things to do and how to do them. Also consider checking on the John Deere website and YouTube for videos to help you DIY.
• Move your mower onto some grass or next to a flower bed, because you’ll be washing it. Then turn it off, remove the key and set the parking brake.
• Use a broom or stiff brush to clean off the grass and debris. Try to get up under the rotary mower deck, and inside the chute and bagger. For really crusted on grass and leaves, gently scrape with a plastic putty knife or a flathead screwdriver.
• Wash your mower with a bucket of water that has a small squirt of mild dishwasher soap. Use a soft sponge or rag. Rinse with water and let the mower dry.
• Wax your mower. Apply car wax to metal and plastic surfaces. Apply engine oil to any surfaces that might rust, like scratches.
• Move the mower into or close to the storage shed or garage where it’s going to overwinter. If you don’t have the space to work on it inside your garage or shed, don’t forget that you’ll have to push it to move it after the next few steps. If you do need to move it later, you may need to pull out the bypass valve that disengages the transmission (see page 25 in the operator’s manual linked below).
• Set the parking brake.
• Empty the fuel tank. First, check your fuel level. Make sure the mower is somewhere well ventilated. If you don’t have much fuel left, the simplest way to empty the tank is to just let the mower run until it can’t. 
• If your fuel tank is full, you can empty it by siphoning off the gas into a gas can using a hand siphon. First, allow the mower to cool and make sure your mower is in a spot that’s well ventilated. Then, tip up the seat and open the fuel tank cap slowly. 
• Check out the siphoning video linked below on how to use a hand siphon. Siphon the gas from the mower tank into the gas can. If you end up with a good amount of gasoline in the gas can, use it quickly. For non-stabilized gas, you’ll need to use it in a month. If you haven’t added a stabilizer to the gas, just use the gas can spout to pour it into your car’s gas tank. 
• After siphoning the gas out, turn on the mower to completely empty the gas tank. Run it until it stops. 
• Put the TRUFUEL non-ethanol gasoline into the gas tank. Your fuel tank should be totally empty. Open up the gas tank cap slowly if it’s closed. Using a funnel, pour in some TRUFUEL engineered fuel in. You won’t need to dump the whole container in – just a quarter or half of the container will be fine.
• Close the gas cap until it clicks and then tip back the seat into the normal position.
• Take out your air filter. Open up the mower hood and locate the two air filter knobs and loosen them (see page 32 in the operator’s manual linked below). Remove the plastic cover over the air filter. Gently take out the air filter and set it aside. You should be able to see the basal tube (aka air cleaner elbow) that runs into the carburetor.
• Lubricate the engine with the STA-BIL fogging oil. The fogging oil will coat the inside of the engine so no moisture can damage your engine over the winter months. To get the fogging oil inside the engine, you’ll be squirting it into the tube at the base of the air filter (aka the cleaner elbow). From there, it will run into the carburetor and coat the rest of the engine. 
• Before you start squirting, make sure your parking brake is still set and you have plenty of air ventilation. 
• Take a couple of minutes to watch the video linked below so you can see exactly where to aim the fogger.
• Then, insert the key and turn on the engine – the engine will be running on the TRUFUEL fuel and without an air filter. Then, spray some fogging oil into the base tube where it runs into the carburetor. If the engine sounds like dying, stop squirting until the engine starts running again. Then squirt again. Repeat several times.
• Turn off the engine and take out the key.
• Install the air filter back in place and put the air filter cover back on.
• Spark plug(s). First, let the mower cool completely. Then, locate the spark plug (see page 34 on the operator’s manual linked below). Disconnect the spark plug by gently pulling off the connecting wire(s). Once the wire is off, figure out which socket fits your spark plug – you may need a long socket. Then, remove the spark plug with your socket wrench. You may need the pliers to hold onto the bolt while you turn the nut with the socket wrench.
• Set the spark plug(s) aside and spray some fogging oil into the spark plug socket. Use the narrow tube on the fogging oil can to spray and coat the spark plug socket. Squirt two or three times.
• With the parking brake still set, turn the mower on for a couple of seconds.
• W​hile the spark plug(s) is out, look it over. If your spark plug has gunk, take a minute to clean it. If it is looking worn or damaged, consider replacing it.
• Reinstall the spark plug(s). Don’t over-tighten the plug – it should be only hand-tight. Then, plug the spark plug wire(s) back on.
• Battery. Locate the battery (see page 41 on the operator’s manual linked below). To overwinter the battery, you will simply unhook the negative and positive cables and remove the battery from the mower. Batteries should always be fully charged before storage, so you may need to use a battery charger to top it up.
• Unhook the negative first. Black is negative. Use the socket wrench to remove the bolt and nut holding the negative cable onto the negative terminal. Store the bolt and nut in a safe place or screw them onto the loose cable for the winter. Push the negative cable to one side – it shouldn’t be touching the battery – while you unhook the positive cable. 
• Locate the red (positive) plastic-coated wire on the positive battery terminal. Use the socket wrench to unscrew the nut and bolt. Store the nut and bolt safely or screw them onto the end of the cable. Push the positive cable aside.
• Take a moment to look at the battery terminals. If they have gunk, consider using a terminal brush to clean them off.
• Pull out the battery.
• Before storing a battery, it should be fully – fully – charged. To fully charge the battery before storage, hook it up to a battery charger. Charge it until it is completely charged – your battery charger should tell you when – or leave it on a trickle charge all winter. 
• Store your battery in a dry spot, on a shelf (not on a concrete floor) and in a spot that won’t get below freezing.
• With the battery out, you are ready to put your mower to bed. If it isn’t already in its storage space, use the bypass valve to disengage the transmission. Take off the parking brake and then push your mower into position.
• Set the parking brake.
• Consider setting out some mice repellent (see below), then cover your mower with a sturdy tarp.

Here’s the link to the video on how to winterize a 100-series John Deere riding lawn mower and here’s the video on how to siphon gas from a riding lawn mower. 

The John Deere 100-series lawn tractor operator’s manual is here.

FAQ: Winterizing a John Deere Lawn Tractor

Should You Run All the Gas Out of Your John Deer Lawn Tractor Before Winter?

Y​ou have two options: run all the gas out of your mower or fill it totally full with a stabilized gas. 

First, consider fire safety. In some cases, it may be safer to store your mower empty. Gas is highly flammable. But if fire safety is not a consideration, then you should store it with the tank totally full with a stabilized gasoline.

A stabilized gasoline is gas station gasoline that has had a stabilizing agent added to it. At most gas stations, some amount of ethanol has been added to the gasoline. The problem comes when you store ethanol. Ethanol goes bad fairly quickly – in just over a month. A stabilizer keeps gas with ethanol from going bad.

A​ll the lawn mower experts we consulted agreed that the worst thing you can do to your mower is to leave it partially filled with ethanol gas. Ethanol is very volatile. Left in a partially filled tank with oxygen, it will attract water vapor.

W​ater vapor in a closed metal tank can cause corrosion – rust. Rust particles in gasoline can damage the engine. In addition, the gasoline will start to sour, which can gum up the carburetor.

Should You Take the Battery Out of Your John Deer Lawn Tractor for the Winter?

T​he battery should be taken out of the mower and fully charged up before winter. Then, store the battery in a spot that won’t dip below freezing. Batteries shouldn’t be stored on a concrete floor, so find a warm spot on a shelf.

Today, many of our power tools have batteries. If your winters are freezing cold, consider gathering all the batteries in your garage and storing them – fully charged – in a warm space.

Is It Better to Drain Gas or Use Stabilizer in My John Deer Lawn Tractor?

W​e checked with John Deere for the answer here. John Deere says that, if you routinely use stabilized fuel, then you should add stabilized fuel to the gas tank until the tank is completely, totally full. A 100% full gas tank reduces the available volume for oxygen, which is essential, because oxygen degrades stabilized gas.

John Deere says that if you don’t routinely use stabilized gas, then you should empty your gas tank. You can either let your engine run until the gas is gone or use a hand siphon to empty it. Then, use a stabilizer in fresh gas and fill the tank totally full. Run the engine for a minute to allow the fresh stabilized fuel to circulate, then turn the engine off. 

A​lternatively, use a non-ethanol fuel like the one we describe in the how-to bullet points above.

How Long Can Gas Sit in My John Deer Lawn Tractor?

I​f you fill your lawn tractor completely with stabilized gas, it can sit for up to six months. If you don’t stabilize your gasoline, then you can leave it for one month before it will start to go bad.

Can I Use Last Year’s Gas in My John Deer Lawn Tractor?

Nope. John Deere recommends using fresh gas in your lawn tractor. If you use gas with ethanol, that means that it should be no more than a month old to be fresh. If you add a stabilizer to your gas, then fresh means three to six months.

When gasoline degrades, the combustible compounds evaporate, so it won’t ignite like it should. When gasoline won’t ignite, the engine will run rough, knock, sputter, miss or even refuse to start. 

Degraded fuel can also produce “varnish” that will gum up your carburetor or, if you have one, a fuel injector system.

How Do I Know if I Have Bad Gas in My John Deer Lawn Tractor?

S​urprisingly enough, you can use your nose. Bad gas smells bad. It smells sour. 

If your nose isn’t sure, then pour a small amount of your suspicious gas into a glass jar and look at it. Good gas is clear, while bad gas is dark.

Can I Leave My John Deer Lawn Tractor Outside in Winter?

J​ohn Deere says your lawn tractor will last longer if you can store it inside. The engine, the body, the tires and everything will last longer. Consider DIYing a lean to or shed if you don’t have a covered space for your tractor.

I​f you absolutely can’t store your mower under a roof for the winter, then be sure to go through the winterizing routine above. Remove the battery and store it on a warm shelf. Invest in a heavy duty cover and run the mower up onto some boards to elevate it just a little.

I​f you have left your John Deere mower out in freezing temperatures, consider changing the gas and the oil before starting your mower.

How Do I Keep Mice Out of My John Deer Lawn Tractor Engine?

This is a very common problem. Mice love to nest in a protected, warm engine surrounded by tasty cables. If you check out the internet, it is filled with advice and amusing Mythbuster-style videos (nope, dryer sheets, ultrasonic repellents and rope lights don’t repel mice).

We recommend green solutions. Try to avoid setting out poisons, which can be a danger to an unexpectedly large number of creatures – including your pets. If the green solutions we recommend don’t work for you, set a couple of old-fashioned mouse traps. If the sight of a dead mouse makes you gag, you can get hygienic mouse traps at most hardware stores.

For an eco-friendly solution, try spraying a mixture of water and peppermint oil, cinnamon oil or both over your mower – especially on the engine – before covering it with a tarp for the winter. 

If you don’t want to spray down your mower, soak cotton balls in peppermint or cinnamon and leave them around your mower or tuck them into the engine space. Other deterrents are: pieces of cedar, dog hair, human hair, cayenne pepper, and mothballs. 

Check online for eco-friendly repellent packs like Earth Kind’s Stay Away products. Simply tuck the packs in spots that mice might like – inside the engine, around the outside of the mower and around the garage or shed where they can come inside.

Keep your garage or shed free from nesting materials. Put dog food and bird seed in metal, mouse-proof containers with sealed lids. Plug up suspicious-looking holes. Add metal strips over the rubber seals on the sides of your garage doors. 

H​ere’s a good guide.

Summary: What Happens if I Don’t Winterize My John Deer Lawn Tractor?

T​hat depends. If you live in a warm climate, maybe nothing at all will happen to your lawn tractor and it starts right up in the spring. But if your climate is harsher than, say, Florida’s, your mower might not start at all. 

I​f you run your mower during the summer on gas with ethanol – you don’t stabilize it – then leaving ethanol gas in your tank can cause metal parts to corrode. Ethanol absorbs water. Water can cause corrosion inside the gas tank, fuel lines, carburetor and your cylinders. Ethanol is also bad for rubber and plastic parts.

W​hen gas degrades, it loses the combustible compounds the engine needs to fire. Your mower may not start at all or it may start and misfire or backfire.

E​ngine oil will also degrade in the cold. If you leave your mower out in freezing weather, you may need to perform an oil change before running it. 

In fact, i​f you have left your John Deere lawn tractor out in freezing temperatures, experts say you shouldn’t even try to start it up without first replacing the gas and engine oil. Running the engine with degraded gas and oil risks damaging it.

In summary, this guide may seem like a lot of work – but you’ll definitely prolong the life of your lawn tractor if you winterize it properly each year. 🙂