How to Clean and Winterise an ATV

When the riding season ends, an ATV does not just sit still; it quietly deteriorates. Fuel goes stale, batteries discharge, moisture finds its way into corners, and mice discover the airbox. A proper approach to how to winterise an ATV (or “winterize”, in American spelling) takes an afternoon and saves you from a hard-starting, rust-spotted machine in spring. The sequence below is general. Your owner’s manual specifies fluids, intervals and procedures for your model, so follow it where it differs.

What you’ll need

• Hose or pressure washer (low setting), bucket, soft brushes and ATV-safe degreaser or mild soap
• Microfibre towels
• Fuel stabiliser suitable for your fuel type
• Fresh engine oil and filter, and coolant if needed
• Grease gun and chain lube (if chain driven)
• Battery charger or maintainer
• Protective spray for metal, plastic and rubber suited to vehicles
• Jack stands or a lift, a cover and rodent deterrents

Step 1: Clean thoroughly

Mud and dirt hold moisture against metal, so start with a proper wash.

1. Let the engine cool. Hot parts and cold water do not mix well.
2. Protect sensitive areas. Plug the exhaust outlet and cover the air intake as the manual advises. Avoid spraying directly at bearings, electrical connectors, the airbox and seals.
3. Rinse off loose dirt from the top down with low pressure. High pressure can force water into bearings, wheel hubs and electrics.
4. Apply degreaser to greasy areas, let it work for a few minutes and agitate with brushes.
5. Wash with soap, paying attention to the underside, wheel wells, A-arms and under the fenders where mud packs.
6. Rinse again thoroughly.
7. Dry with towels and let the machine air dry. Run the engine briefly (outdoors) to burn off moisture in the exhaust, then let it cool.

While you clean, inspect for damage: worn bushings, torn boots, cracked plastics, leaks and loose bolts. Winter is the ideal time to fix them. See the ATV maintenance checklist for what to look for.

Step 2: Change the oil and filter

Used engine oil contains acids and moisture that can corrode internal parts during storage. Change the oil and filter before storing, rather than after.

1. Warm the engine slightly so the oil drains well.
2. Drain the oil into a pan and dispose of it at an approved recycling point.
3. Replace the filter and fill with the grade and quantity listed in the manual.
4. Check the level.

Also consider changing differential and final-drive oils if they are due, and check for water contamination (milky fluid).

Step 3: Treat the fuel system

Fuel degrades over time and can leave gummy deposits that clog carburettors and injectors.

Option A: Fill the tank and add stabiliser.
1. Fill the tank nearly full to reduce air space, which limits condensation.
2. Add fuel stabiliser at the ratio on the label.
3. Run the engine for several minutes so that stabilised fuel reaches the fuel lines and carburettor or injectors.

Option B (carburettor models): Drain the float bowl. Some manufacturers recommend turning off the fuel valve and running the engine until it stops, or draining the carburettor float bowl via the drain screw. Follow your manual’s guidance.

Don’t use fuel containing high ethanol content in machines not designed for it, and do not store gasoline indoors in unapproved containers.

Step 4: Protect the engine internals

Some riders “fog” the cylinder to protect against corrosion over long storage periods:

1. Remove the spark plug(s).
2. Spray a small amount of fogging oil into the cylinder, per the product instructions.
3. Turn the engine over a couple of times by hand or briefly with the starter (with the plug grounded and away from fuel vapour), as your manual allows.
4. Refit the spark plugs.

Fogging is optional on many modern machines, and procedures differ, so check the manual or ask a qualified mechanic before you try it.

Step 6: Lubricate

Lubricate all grease points on suspension and steering components, driveshaft joints if fitted, and pivot points. Clean and lube the chain on chain-driven models. Lightly oil cables where recommended. Apply a silicone-based protectant to rubber seals and boots, taking care not to get it on brake discs, pads or tyres’ tread.

Step 7: Battery care

Batteries lose charge in storage, and a deeply discharged battery may be ruined by a frozen winter.

1. Disconnect the negative terminal, or remove the battery.
2. Clean the terminals with a wire brush and a baking-soda solution if corroded, then rinse and dry.
3. Charge fully with a charger matched to the battery type (lead-acid, AGM, lithium).
4. Store in a cool, dry place off bare concrete if you remove it.
5. Use a battery maintainer (a smart charger) throughout storage. Don’t leave a standard charger connected indefinitely.

Step 8: Tyres, suspension and brakes

• Relieve load from the tyres by putting the machine on stands, or at least inflating tyres to the upper end of the recommended range for storage so they hold shape. Check manual guidance.
• Check brake fluid level and condition; replace if due.
• Release the parking brake if the manual recommends it to avoid pads sticking to discs. Use wheel chocks instead.
• Inspect pads and discs for wear and rust.

Step 9: Seal openings and protect against pests

Mice and insects love airboxes, exhaust pipes and seat foam.

• Cover the exhaust outlet and the air intake with a plug that is clearly visible, so you remember to remove it before starting. Attach a reminder tag to the key.
• Use rodent deterrents such as repellent products or traps nearby; avoid placing poison where pets or children could access it.
• Remove food, bedding and nesting material from the storage space.
• Close vents per the manual, and fit a breathable cover.

Step 10: Choose the storage spot

The best place is dry, ventilated, secure and out of direct sunlight.

• A garage or shed is better than outdoors.
• Avoid damp basements and areas with chemicals or sparks.
• Use a breathable cover, not plastic sheeting, which traps moisture.
• Keep the machine off the bare ground.
• Make sure the space is secured against theft; lock the steering and consider an alarm or wheel lock.
• Check your insurance policy in case it has storage conditions:.

Spring start-up

1. Remove covers, plugs and reminder tags.
2. Check tyres, brakes, fluids and fasteners again.
3. Reconnect the battery and check it holds charge.
4. Inspect for chewed wires or nests.
5. If the fuel is old, replace it or add fresh fuel following the manual.
6. Start the engine and let it idle, watching for leaks and unusual noises.
7. Test lights, brakes and gears at low speed in a safe area.

If the machine struggles to start or runs poorly, you may have fuel problems and need a service.

Quick winterising checklist

Task	Done
Wash and dry
Oil and filter change
Fuel stabiliser, tank full
Lubricate grease points and chain
Coolant check
Battery charged, maintainer connected
Tyres and brakes inspected
Exhaust and intake covered
Pest deterrents in place
Breathable cover and secure storage

Frequently asked questions

Do I need to winterise if I ride in winter?

Not in the same way, but regular cleaning, lubrication and battery care become more important, since salt, snow melt and mud are harsh on components.

Is fuel stabiliser really necessary?

For storage of a few months, stabiliser helps prevent varnish and gum. It is not a substitute for fresh fuel in spring if the fuel is very old.

Can I store the ATV outside?

It’s not ideal. If you must, use a quality breathable cover, a raised base and extra security, and expect more moisture and pest problems.

Should I remove the battery?

Either remove it or keep it connected to a maintainer. A battery left to discharge in the cold can be damaged permanently.

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Conclusion

A clean, serviced, properly stored ATV starts in spring and keeps its value. Wash it, change the oil, stabilise the fuel, care for the battery, protect against pests and store it in a dry place. Follow the manual for details specific to your model, and the first ride of next season will be a pleasure instead of a repair job.