How To Winterize A Dirt Bike: Storage Steps From The Owner's Manuals

Quick Winter Storage Checklist

1. Do any repairs now. KTM, Husqvarna, Yamaha and Honda manuals all say to check the bike and fix problems before storage, and KTM points out the shop is less busy in the off season.
2. Wash and dry the bike, then lube the chain, cables and pivots.
3. Deal with the fuel the way your manual says: stabilize and fill, or drain (see the table below).
4. Change the engine oil (4-stroke) or gear oil (2-stroke) so the engine does not sit on dirty, acidic oil.
5. Check coolant frost protection, or drain it if your manual says so.
6. Remove the battery, charge it fully, and keep it maintained somewhere cool and dry, above freezing.
7. Set tire pressure and get both wheels off the ground.
8. Plug the muffler outlet against moisture and use a breathable cover.
9. Do not start the bike for a few minutes "to keep it fresh."
10. Write down what you did and set a spring reminder.

The rest of this guide explains each step with the specific instructions from the owner's manuals, then splits out what is different for 2-strokes, 4-strokes, fuel-injected bikes and electric bikes like the Stark Varg.

Fuel: Stabilize Or Drain?

This is where manuals disagree the most, so follow the one for your bike:

The logic behind both camps is the same: old fuel goes stale, and a part-empty steel or plastic tank can collect condensation. Stabilizing a full tank protects the tank and pump. Draining protects a carburetor's tiny jets from varnish. On carbureted bikes, the float bowl is the part that clogs, so drain it even if you stabilize the tank.

If you use a stabilizer, follow the maker's directions exactly. Gold Eagle says STA-BIL Storage keeps fuel fresh for up to 24 months, treats up to 2.5 gallons per ounce, should be added only to fresh fuel, and the engine should run for 5 minutes after adding it so treated fuel reaches the whole fuel system. They also recommend keeping the tank 95 percent full to limit condensation. KTM group manuals list Motorex Fuel Stabilizer as their recommended fuel additive. A stabilizer slows the fuel going stale, but it does not stop ethanol fuel from absorbing water and separating, so draining the carb or using ethanol-free fuel is still the safer bet for a long layup.

Premix does not stay fresh for long. Yamaha's YZ manuals say to mix the day of the race. Do not leave a can of old premix to use in spring; see our 2-stroke premix ratio guide.

Oil And Coolant

Oil: KTM and Husqvarna 4-stroke manuals list "change the engine oil and the oil filter, clean the oil screens" as a storage step. KTM 2-stroke manuals list "change the gear oil." Honda's CRF125F manual changes the engine oil before storage, and the CRF250R and CRF125F manuals say to change it again on removal from storage if the bike sat for more than four months. Fresh oil means the engine is not sitting all winter on combustion byproducts and moisture. See how often to change dirt bike oil for the details.

Coolant: freezing coolant can crack a cylinder or radiator, so check it before the first cold night.

• KTM's 2026 manuals say to check the frost protection, with a specified range of minus 25 to minus 45 °C (minus 13 to minus 49 °F), and to use coolant with antifreeze protection to at least minus 25 °C (minus 13 °F).
• Yamaha's 2026 YZ250F manual specifies a coolant mixing ratio of 1:1 (coolant to water).
• Honda's 2026 CRF250R manual takes a different approach: drain the coolant for storage, then pour in a fresh recommended coolant mixture when you take the bike out. Honda specifies Pro Honda HP Coolant.

A cheap coolant hydrometer or refractometer tells you whether your mix will survive your coldest night. If you do not know when the coolant was last changed, winter is a good time to do it.

Battery Storage

Most modern dirt bikes with electric start use lithium-ion batteries, and they need a little more care than old lead-acid units.

• KTM and Husqvarna: remove the 12 V battery and charge it. The manuals list an ideal charging and storage temperature of 10 to 20 °C (50 to 68 °F) for the lithium-ion battery.
• Yamaha YZ250F: remove the battery, fully charge it, store it in a cool, dry place and charge it once a month. Do not store it below 0 °C (32 °F) or above 65 °C (149 °F).
• Honda CRF125F: remove the battery and slow charge it every 30 days, stored off the floor away from freezing temperatures and direct sunlight. If you leave it in, disconnect the cables (negative first).
• Honda CRF250R: remove the battery, fully charge it and keep it in a shaded, well-ventilated area, or disconnect the negative terminal if it stays on the bike.

Battery Tender's winter storage guide adds useful context. It lists self-discharge of about 3 to 5 percent per month for lead-acid and 1 to 2 percent per month for lithium. It also warns that lithium batteries cannot be charged below 32 °F (0 °C) and need a lithium-compatible charger. A discharged lead-acid battery can freeze. In short: bring the battery inside, and use a maintainer that matches the battery chemistry.

Where And How To Park It

The manuals agree on the environment, and a few details are easy to miss:

• Dry, steady temperature. KTM: a dry location not subject to large temperature swings. Honda: an unheated area, free of dampness, away from sunlight, with minimal daily temperature variation.
• Avoid damp cellars and barns. Yamaha warns against damp cellars, stables (because of ammonia) and areas with strong chemicals.
• Wheels off the ground. KTM recommends a lift stand. Yamaha says to set tire pressure and lift the bike so both wheels are off the ground, or turn the wheels a little every month so the tires do not degrade in one spot.
• Breathable cover only. KTM and Honda both say to use a cover that lets air through. Non-porous plastic traps moisture and causes corrosion.
• Close off the exhaust. Yamaha says to cover the muffler outlet with a plastic bag. Honda says to stuff a rag in the outlet and tie a bag over it.
• Protect bare metal. Yamaha recommends corrosion protection spray on metal surfaces and lubricating all control cables and lever, pedal and stand pivots.

One more KTM note that surprises people: avoid starting a stored bike and running it for a short time. The engine never gets warm enough, so water vapor from combustion condenses inside and rusts engine parts and the exhaust.

2-Stroke Storage

2-strokes have a few extra steps because there is no oil sump protecting the bottom end and cylinder.

• Fog the cylinder (Yamaha method). For long-term storage the YZ125 manual says to remove the spark plug, pour a tablespoon of motor oil into the plug hole, reinstall the plug, and kick the engine over several times with the engine stop switch pushed in to coat the cylinder walls.
• Drain or stabilize. Yamaha drains the tank, lines and float bowl on the YZ125. KTM uses fuel additive and a full tank, and on the carbureted 85 SX also empties the float chamber.
• Change the gear oil. KTM's 125 SX, 85 SX and 300 XC-W storage chapters all include it.
• Oil-injected models: the KTM 300 XC-W storage list includes adding 2-stroke oil to the oil tank after the last fill.
• Dump old premix. Start spring with a fresh batch at your manual's ratio.

More 2-stroke care: 2-stroke maintenance guide.

4-Stroke Storage

• Fresh oil and filter before storage (KTM, Husqvarna, Honda CRF125F), and again in spring if Honda's four-month window has passed.
• Fog the cylinder (Yamaha YZ250F method). Remove the plug cap and plug, pour a teaspoon of engine oil into the plug bore, ground the plug electrodes against the head with the cap fitted to limit sparking, turn the engine over several times with the starter, then reinstall the plug and cap. Yamaha includes a warning to ground the electrodes so sparks cannot cause damage or injury.
• Carbureted 4-strokes such as the CRF125F: fill the tank per Honda, and plan to replace the fuel if the bike sits more than two months. If your carburetor has a float bowl drain, emptying it prevents varnish in the jets.

See the 4-stroke maintenance guide for oil, valve and filter intervals.

Fuel-Injected Bikes

Fuel injection removes the float bowl problem, but the fuel pump and injector still sit in fuel all winter. The manuals give two valid approaches:

• Full tank plus stabilizer (KTM, Husqvarna, GASGAS and the Yamaha YZ250F). Run the engine briefly after adding stabilizer so treated fuel reaches the pump and injector, as the stabilizer maker directs, then shut it off and leave it.
• Drain the tank (Honda CRF250R). Relieve the fuel pressure first and drain into an approved container. When you bring the bike out, refill with the recommended fuel and "increase the fuel pressure" (Honda's term for re-priming the system) before starting.

Either way, use the lowest-ethanol fuel you can get, as KTM recommends, and do not leave the tank half full of untreated fuel.

Electric Dirt Bikes: Stark Varg Storage

Electric bikes skip the fuel and oil steps but have a large lithium battery that needs managing. Stark's VARG MX 1.2 owner's manual gives these storage rules:

• Store at 0 to 30 °C, with 10 °C preferred.
• Clean the bike before storage.
• Keep the battery charge between 30 and 50 percent.
• Check charge regularly; if it drops below 30 percent, recharge to 50 percent.
• Store in a dry area free from frost.
• Monitor battery status every two weeks and do not let the battery discharge completely.

Do not store an electric bike at 100 percent "so it is ready in spring." The manual's 30 to 50 percent window is the target. More on electric care: electric dirt bike maintenance and the Stark Varg maintenance checklist.

Spring Recommissioning Checklist

Taking the bike out of storage is where most "it ran fine in October" problems show up. KTM's procedure is: install the battery, take the bike off the stand, do the normal pre-ride checks, then take a test ride. Honda's adds cleaning, oil and fuel steps. Combined:

1. Uncover and clean the bike. Remove the rag and bag from the muffler outlet.
2. Change the engine oil if it has been more than four months (Honda's rule), and replace fuel that sat in a carbureted bike more than two months (CRF125F).
3. Refill coolant if you drained it, and check the level and frost protection if you did not.
4. Charge and install the battery.
5. Fill with fresh fuel (and fresh premix at the correct ratio for 2-strokes). On a drained fuel-injected Honda, re-pressurize the fuel system per the manual.
6. Run the KTM pre-ride list: electrics, oil level, brake fluid level and pads, brake function, coolant level, chain condition and chain tension, tire condition and pressure, spoke tension, fork dust boots and bleeding, air filter, controls, fasteners and fuel level.
7. Clean and re-oil the air filter if it was put away dirty. Our air filter cleaning guide covers it.
8. Start the bike, let it warm up properly, and take an easy test ride before you push it.

If it will not fire, work through our dirt bike won't start guide; stale fuel and a flat battery are the usual suspects after winter.

Set It As A Date Reminder

Winter storage is one of the few maintenance jobs that runs on the calendar, not engine hours, which makes it a good fit for a date-based task. In MotoMind: Dirt Bike Service for iPhone, MotoMind Pro lets you add a "Winter storage prep" task and a "Spring recommissioning" task with dates, and date-based tasks send push reminders. You can also log the oil change, battery charge and fuel stabilizer as service records, so in spring you know exactly what was done and when. Apple Calendar sync (Pro) can put the dates on your calendar too.