Seasonal Maintenance for Powersports Equipment

Powersports equipment spends more of the year parked than running, and the months it sits are what decide its condition. In one sentence: the two jobs that matter most are putting the machine away correctly (stabilized fuel, a fully charged battery on a maintainer, and protection from moisture and rodents) and checking it properly before the first ride back. Skip the first and you will pay for it in the second. This guide covers both halves of the cycle, for motorcycles, ATVs, UTVs, snowmobiles, and personal watercraft.

When Should You Winterize, and When Should You Recommission?

Most powersports equipment follows the same calendar, with one important exception. A snowmobile runs in the season everything else sits out, so its storage period is summer, not winter. The tasks are identical either way. Only the timing flips.

The rule of thumb underneath all of it: if the machine will sit for a month or more, treat it as storage. A two-week gap needs nothing. A three-month gap needs the full routine.

How Do You Winterize a Powersports Vehicle?

Work through these in order. The whole job takes an afternoon and prevents most of the problems in the spring section below.

1. Fill the tank and add fuel stabilizer. Fuel degrades in storage, and ethanol-blended fuel can attract enough moisture to separate in the tank, leaving a layer that will not burn and can corrode fuel system components. Add stabilizer to fresh fuel rather than old, fill the tank to roughly 90 percent (full enough to limit condensation on the tank walls, with room for expansion), then run the engine for five to ten minutes so the treated fuel actually reaches the carburetor or injectors. Stabilizer sitting in the tank while untreated fuel sits in the fuel lines does nothing.

2. Change the oil and filter. Used oil carries combustion acids and moisture that will sit against internal components for months. Changing it before storage rather than after is one of the highest-value steps on this list, and it costs the same either way.

3. Fully charge the battery and put it on a maintainer. This is the step most often skipped and most often regretted. A lead-acid or AGM battery self-discharges roughly 1 to 3 percent per week at room temperature, so a battery left alone through a long off-season can drain to a point where it never fully recovers. Charge it completely, then either connect a maintainer or disconnect the negative cable and plan to recharge monthly. A charged battery also resists freezing far better than a discharged one, which matters in an unheated garage.

4. Deal with the tires. Inflate to the recommended pressure, and if possible get the weight off the tires using a stand or blocks to prevent flat spots. Tires lose pressure over months regardless.

5. Wash and protect. Dirt, road salt, and trail grime hold moisture against metal for the entire storage period. Wash the machine, dry it thoroughly, and apply a corrosion inhibitor to exposed metal. Salt-exposed machines need this most.

6. Block the openings and think about rodents. Exhaust outlets and air intakes are attractive winter housing. Plug them (and leave yourself an obvious reminder to remove the plugs), and keep bait or deterrents around the storage area. A mouse nest in an airbox is a common and entirely preventable spring surprise.

7. Cover it, but let it breathe. Use a breathable cover rather than a plastic tarp. Sealed plastic traps condensation against the machine and causes more corrosion than leaving it uncovered would.

8. Personal watercraft and snowmobiles need extra steps. A PWC should be flushed with fresh water, drained, and have the engine fogged per the manufacturer's instructions before winter. A snowmobile going into summer storage should have the track and suspension checked and the machine stored off the ground with the track unweighted.

How Do You Get Powersports Equipment Ready After Storage?

Come the first ride of the season, resist the urge to just pull the cover off and hit the starter. Work this checklist instead. Give yourself a week of lead time, because this is exactly when people discover they need a part or a replacement battery in a hurry.

1. Inspect before you touch anything. Look and feel your way over the machine before its first run. Check for insect or rodent nests in the exhaust and airbox, and look hard at brake and throttle cables for gnaw damage. Finding a chewed brake cable in the garage is vastly better than finding it on the trail.
2. Check and change the fluids. Oil, coolant, and brake fluid all matter. Some drop gradually, some thicken over months, and some absorb moisture and degrade. If you did not change the oil going into storage, change it now before the first start. Brake fluid in particular is worth erring on the side of replacing.
3. Check plugs, chains, belts, and filters. Spark plugs, drive chains and belts, and air filters all age in storage. Order replacements early rather than discovering a stretched chain or a nested air filter the morning you wanted to ride.
4. Check tires and wheels. Tires will have lost pressure, so inflate them first. Then inspect the rubber for cracking and splitting, which spreads quickly once it starts, and check the remaining tread. At the wheels, confirm the nuts are tight, the brake pads have life left, and no debris has built up.
5. Test the battery. Whether or not it was on a maintainer, test it before you rely on it. See the next section for how to read the numbers correctly.
6. Check the fuel. If the machine was stored without stabilizer, the fuel may be stale. Stale fuel causes hard starting, rough running, and clogged jets. Drain and replace it rather than trying to run it off.
7. Wash it thoroughly. A proper wash removes the dust and grime of storage and, more usefully, exposes anything the initial inspection missed. Leaks, cracks, and corrosion are much easier to see on clean metal.
8. Take a short shakedown ride. Stay close to home the first time out and pay attention to braking, shifting, and charging. Problems surface in the first twenty minutes.

How Do You Test a Battery After Storage?

This is where a lot of seasonal advice goes wrong, because there are two different voltage tests and they have two different correct answers. Confusing them is the most common battery testing mistake there is.

Test 1, resting voltage (engine off). Measure at the terminals with the engine off, ideally several hours after any charging. This tells you the battery's state of charge.

Test 2, charging voltage (engine running). Measure at the terminals with the engine running at a fast idle. You should see roughly 13.5 to 14.5 volts, which confirms the charging system is replenishing the battery. A reading near 14 volts here is healthy and expected. That same reading on a battery at rest would be abnormal, which is why the two tests must not be mixed up.

Put the two together and the diagnosis is usually obvious. Low at rest but healthy while running means the battery was simply drained by storage. Low at rest and still low while running points at the charging system, not the battery. Healthy after a charge but flat again within a few days means the battery itself is done.

Most powersports batteries last 3 to 5 years. If yours is in that window and failing these tests, replace it rather than nursing it through another season. For the full detail on battery types, cold cranking amps, and what to look for in a replacement, see a few things to know about powersports batteries.

Common Seasonal Mistakes

• Starting the machine every few weeks in storage. This is the most widespread bad advice in powersports. A brief run draws more from the battery through the starter than a short idle replaces, so each cycle leaves the battery further behind. It also introduces moisture into the exhaust without ever getting hot enough to burn it off. Use a maintainer instead.
• Adding stabilizer without running the engine. Untreated fuel stays in the lines and carburetor, which is exactly where varnish causes problems.
• Covering with plastic. Trapped condensation causes more corrosion than no cover at all.
• Storing a discharged battery in the cold. A flat battery is far more vulnerable to freezing than a charged one, and a frozen battery is finished.
• Leaving it until the weekend you want to ride. Parts and batteries take time to arrive. Start a week out.

Need a Replacement Battery?

We hear from riders every spring who need a battery immediately and end up paying premium rates to get one in time. Testing early is the fix. If the battery does not pass, AJC Battery stocks AGM replacements shipped factory activated, charged, and ready to install, with fast shipping to most of the USA.

• Motorcycle batteries
• ATV batteries
• UTV and side-by-side batteries
• Snowmobile batteries
• Personal watercraft batteries
• Browse all AJC powersports batteries

Make sure the replacement is a correct match the first time so you are not waiting on a return. Check that the voltage, terminal type and position, and case dimensions line up with the battery coming out, and meet or exceed its cold cranking amps. Our guide on how to find a replacement battery for anything walks through the process.

Frequently Asked Questions

How do you winterize a motorcycle?

Fill the tank to about 90 percent with fresh fuel, add stabilizer, and run the engine five to ten minutes to circulate it. Change the oil and filter, fully charge the battery and connect a maintainer, inflate the tires and get the weight off them if you can, wash and dry the machine, plug the exhaust and intake against rodents, and cover it with a breathable cover.

Should you start a stored motorcycle or ATV periodically?

No. A brief start draws more current through the starter than a short run puts back, so the battery ends up further behind after each attempt. It also puts moisture into the exhaust without running long enough to evaporate it. A battery maintainer does the job properly with none of the downsides.

What voltage should a powersports battery read after storage?

At rest with the engine off, a fully charged AGM battery reads about 12.8 to 13.0 volts, and a conventional battery about 12.6 to 12.7 volts. Below 12.4 volts it needs recharging. With the engine running, the terminals should read roughly 13.5 to 14.5 volts, which confirms the charging system is working. Those are two separate tests with two different correct answers.

What is the difference between a trickle charger and a battery maintainer?

A basic trickle charger supplies a small steady current regardless of the battery's state, so it can overcharge a battery left connected for months. A maintainer, sometimes called a smart charger, monitors the battery and switches to a float mode once it is full. For long-term storage a maintainer is the right tool.

How long does fuel stabilizer last?

Most stabilizers keep fuel usable for around 12 months, though this varies by product, so check the label. Add it to fresh fuel rather than fuel that has already begun to degrade, and run the engine afterward so the treated fuel reaches the whole fuel system.

How do you store a snowmobile in the summer?

The same routine as winter storage, just on the opposite calendar. Stabilize the fuel and run the engine to circulate it, change the oil, fully charge the battery and put it on a maintainer, clean and dry the machine, check the track and suspension, store it off the ground with the track unweighted, and use a breathable cover.

How long does a powersports battery last?

Typically 3 to 5 years, and closer to 2 to 3 years on machines stored through long off-seasons without a maintainer. Deep discharges, chronic undercharging, heat, and vibration all shorten it.

What should you check first after winter storage?

Inspect before starting. Look for rodent or insect nests in the exhaust and airbox and check the brake and throttle cables for gnaw damage, because those are the failures that become dangerous once you are moving. Then work through fluids, plugs and belts, tires, the battery, and the fuel.

Give Yourself a Head Start

Seasonal maintenance is mostly a timing problem. The machine does not care whether you do the work in October or April, but it does care whether the fuel was stabilized and whether the battery spent the off-season on a maintainer. Put it away properly, test it a week before you want to ride rather than the morning of, and the first run of the season is uneventful. When the battery does not pass, shop AJC replacement powersports batteries and get back out there.