Quick answer: To winterize a powersports vehicle, clean and dry it, change the oil, stabilize or drain the fuel, top off or remove the battery and put it on a tender, fog the engine, protect against rodents, and store it elevated under a breathable cover in a dry space. Done right, the whole process takes an afternoon and saves you from expensive repairs and a no-start headache in spring.
As riding season winds down, how you put your machine away matters more than most riders think. The damage that ruins a spring startup — gummed-up fuel, a dead battery, corroded internals, a mouse nest in the airbox — almost always happens during storage, not during riding. This guide walks through every step so your ATV, UTV, motorcycle, dirt bike, or jet ski fires up on the first warm weekend of the year.
Why winterizing matters
Ethanol-blended pump gas begins to break down in as little as 30 days. Over a few months of storage, it forms varnish and gum that clog carburetors and fuel injectors, and its ethanol content can absorb moisture and separate from the gasoline. Meanwhile, an unmaintained battery slowly discharges and can freeze, oil settles and leaves internal parts unprotected, and rodents look for a warm place to nest. A couple of hours of prep now prevents all of it.
The complete winterization checklist
1. Clean and dry the whole machine
Wash off mud, salt, bug residue, and grime — these hold moisture against metal and accelerate corrosion. Rinse the radiator fins, let everything dry completely, then apply a coat of wax to painted and chrome surfaces and lubricate cables and chains. A clean machine going into storage is a machine that comes out rust-free.
2. Change the oil and filter
Used oil is acidic and full of combustion byproducts that will pit and corrode internal components if left sitting all winter. Change the oil and filter before storage, not after. On ATVs and UTVs, take care of transmission and differential fluids at the same time if they're due. Fresh motor oil is cheap insurance for your engine.
3. Stabilize or drain the fuel
You have two options. Either run the machine completely out of gas, or fill the tank and add a fuel stabilizer at the correct dose, then run the engine for 5–10 minutes so treated fuel reaches the carburetor or injectors. A full, stabilized tank is preferred for most modern EFI machines because it prevents condensation inside the tank. If your vehicle has a carburetor, close the petcock and drain the float bowl to prevent varnish buildup.
4. Fog the engine
For long storage, fogging oil coats cylinder walls, pistons, and valves with a protective film that stops surface rust. Remove the air filter, start the engine, and spray fogging oil into the intake until the engine runs rich and nearly stalls. (On some four-strokes you can spray directly into the spark plug holes instead — check your owner's manual.)
5. Service the air filter
A dirty air filter degrades over months of storage and makes spring startup harder. Clean or replace it before the machine goes away, then block the airbox intake to keep critters out.
6. Take care of the battery
The battery is the number-one spring casualty. Either remove it and store it somewhere it won't freeze, or leave it installed and connect a battery tender or trickle charger to keep it topped off. A quality AGM powersports battery that's maintained over winter will last years longer than one that's drained flat and frozen.
7. Block out rodents
Mice will nest in an airbox, chew wiring, and pack exhaust pipes with insulation in a single winter. Plug the exhaust outlet and airbox intake with steel wool or purpose-made plugs (remember to remove them in spring), and consider rodent deterrents around the storage area.
8. Protect the tires and store it right
Store the vehicle in a garage, shed, or other dry, temperature-stable space. Elevate it on a stand or blocks so weight comes off the tires — this prevents flat spots over months of sitting. Finish with a breathable cover; avoid plastic tarps, which trap condensation against the machine.
Jet ski and PWC extras
Personal watercraft need a few water-specific steps: flush the cooling system with fresh water, drain all water from the exhaust and engine, lubricate seals and fittings with a corrosion-blocking spray, spray fogging oil into the intake, and stabilize the fuel. Store the PWC on a trailer or stand out of direct sunlight. If you upgraded your ski this summer, our guide to jet ski and PWC upgrades pairs well with proper off-season care.
Spring wake-up: don't forget
Come spring, reverse the key steps before you ride: remove the exhaust and intake plugs, reinstall the charged battery, check tire pressure, inspect brakes and controls, and let the engine warm up before you push it. A machine that was stored properly should start on the first or second crank.
Winterization FAQ
How long can fuel sit in an ATV or motorcycle before it goes bad?
Untreated ethanol-blended fuel can start degrading in about 30 days. With a fuel stabilizer added and run through the system, treated fuel stays usable for roughly 12–24 months.
Should I start my stored ATV or motorcycle periodically over the winter?
Generally no. Brief idling doesn't fully warm the engine or recharge the battery, and it introduces moisture into the oil and exhaust. It's better to winterize properly once and leave the machine alone until spring.
Do I need to remove the battery, or is a tender enough?
Either works. A battery tender or trickle charger left connected keeps the battery healthy in place. If your storage space gets below freezing and you can't run a charger there, remove the battery and store it somewhere warmer.
What happens if I skip winterizing?
The most common results are a dead or frozen battery, gummed-up fuel that won't let the engine start, internal corrosion from acidic old oil, and rodent damage to wiring and the airbox — often adding up to hundreds of dollars in spring repairs.
Is winterizing different for a fuel-injected vs. carbureted machine?
Mostly the same, but carbureted machines need the float bowl drained (or the fuel run out completely) to prevent varnish in the carb. EFI machines do best with a full tank of stabilized fuel to limit condensation.
Ready your machine for spring
The best time to winterize is the moment riding season ends — not the weekend before you want to ride again. Stock up on fresh oil, a battery charger, a replacement air filter, and a quality battery at Powersports Haven, and your ATV, UTV, motorcycle, or jet ski will be ready to run the day the weather breaks.
