Winterize a gas or battery lawn mower safely with the model-specific fuel, battery, blade, cleaning, and dry-storage steps that prevent spring repairs.
To winterize a lawn mower, clean and dry it, disable the power source, inspect the blade and deck, and then prepare either the fuel system or battery exactly as the manufacturer directs. Store the mower in a dry, protected place only after it has cooled; never run a gas engine indoors or leave fuel fumes near a flame, spark, furnace, or water heater.
The power source changes the job. Stale fuel and the wrong oil procedure can damage a gas mower; an empty, damp, or improperly stored pack can sideline a battery mower.
Start with the model number, not a shopping list
Find the mower's model and serial label. Gas equipment may also have a separate engine model. Battery instructions can differ by pack and charger even when two mowers share a brand.
Read the storage and maintenance sections before draining anything, tipping the deck, adding stabilizer, changing oil, or choosing a battery charge level. Lowe's presents running the fuel system dry and storing with fresh stabilized fuel as two common gas-mower options, but says to use the method specified for the machine. Some gas engines don't use the old drain-and-refill oil routine, and lithium-ion makers don't all specify the same storage charge.
My view: the manual is part of the tool. Finding it is cheaper than guessing how a carburetor, battery pack, or folding-storage design works.
Supplies and service costs to expect
Buy by model number. Use a “universal” part only when the manufacturer lists it as compatible.
| Item or service | Typical cost | What the number includes |
|---|---|---|
| Engine oil, one quart | $4–$8 | A common retail supply range; the manual controls grade and capacity |
| Fuel additive or stabilizer | $5–$20 | Check treatment ratio and storage claim on the label |
| Spark plug | $4–$12 | Match the exact approved part and gap specification |
| Air filter | $6–$25 | Foam, paper, and combination filters are serviced differently |
| Blade sharpening | $5–$30 per blade | Ask whether balancing is included |
| DIY tune-up supplies | $20–$80 | Typical oil, filter, plug, and related consumables; parts vary by mower |
| Professional walk-behind tune-up | $85–$200 | Range spans push and self-propelled models and differing service scopes |
| Professional riding-mower tune-up | $175–$350 | More blades, filters, belts, battery checks, and handling can raise the price |
| Basic electric walk-behind service | $55–$145 | Usually cleaning, blade work, lubrication, vents, and inspection rather than engine service |
The ranges come from LawnStarter's 2026 mower-repair cost data; Angi's 2026 service data also shows wide variation by mower and scope. Pickup, diagnostics, parts, carburetor work, and warranty requirements can change the quote. Compare written scopes, not the words “basic tune-up.”
Steps every mower needs
1. Pick a safe work area
Use a hard, level surface with good light and ventilation. Let the machine cool. Keep children and pets out, and move gasoline away from grinders, pilot lights, chargers, and anything that can spark.
The U.S. Consumer Product Safety Commission says to stop the mower, wait for the blade to stop, and disconnect the spark plug before maintenance or repairs. For a battery mower, remove the safety key and battery pack. A corded mower must be unplugged. Wear sturdy gloves around a blade; add eye protection if you're scraping or sharpening.
2. Clean it without forcing water where it doesn't belong
Brush loose clippings from the top, wheel areas, vents, and bag. Scrape packed grass from the underside with a plastic or wood tool after power is disabled. Damp clumps hold moisture against steel.
Don't tip a gas mower until you know the approved direction. Lowe's notes that many walk-behind mowers are positioned with the air filter facing up, but the exact manual wins. Tipping the wrong way can move oil or fuel where it shouldn't go. Avoid pressure washing unless the manufacturer permits it, and let every surface dry before storage.
3. Inspect before putting the problem away
Look for a bent or cracked blade, deep nicks, heavy corrosion, a rusted deck, loose hardware, frayed control cables, split wheels, a torn grass bag, and damaged guards. Spin only the parts the manual says can be checked by hand, with power disabled.
A dull, sound blade may be sharpened and balanced if the manufacturer allows it. Replace a bent, cracked, badly damaged, or questionable blade. Don't hammer it straight. University of Minnesota Extension notes that a sharp blade makes a cleaner cut and leaves grass less vulnerable to disease while conserving water better.
Gas mower winterization branch
1. Choose one approved fuel-storage method
Don't add stabilizer to months-old gasoline and assume the problem is solved. Use fresh fuel and the treatment ratio on the product label if the manual calls for stabilized storage. Run the engine outdoors for the specified time so treated fuel reaches the carburetor, then shut it down and let it cool.
If the manual instead calls for empty storage, transfer fuel outdoors into an approved gasoline container using the specified method, then run the engine outdoors until it stops if directed. Never siphon by mouth. Don't pour gasoline onto the ground, into a drain, or into household trash. Your local household hazardous-waste program can explain what it accepts.
Briggs & Stratton's storage guidance says gasoline can begin degrading in as little as 30 days and describes stabilized-fuel and empty-system routes. The important part isn't picking a side from a generic article. It's following the storage method for the exact engine.
2. Handle oil by the engine instructions
Check the oil on level ground. If the schedule calls for a change, use the listed grade, capacity, drain method, and recycling route. Don't overfill. Some newer engines are designed around checking and adding oil rather than routine draining, so “always change it in fall” is bad universal advice.
3. Service the filter and plug only as needed
A paper air filter may need replacement rather than washing. A foam filter may use a different cleaning and oiling process. Follow the engine manual. Inspect or replace the spark plug at the stated interval and tighten it to specification; don't guess at the gap or torque.
Cylinder fogging or adding oil through the plug hole is model-specific. Do it only if the manufacturer calls for it. Reconnect the plug wire only after all blade and underdeck work is finished, unless the storage directions say to leave it disconnected.
Battery mower winterization branch
1. Remove the key and pack
Let the battery cool after the final mow. Remove the safety key and detachable pack before cleaning or blade work. Brush debris from the compartment and contacts with a dry tool. Don't insert metal into terminals.
A swollen, cracked, leaking, punctured, corroded, or heat-damaged pack should not be charged or opened. Move away from a smoking or burning battery and call emergency services. For a damaged but stable pack, follow the maker's handling instructions and use a battery-recycling location.
2. Follow the battery's own storage target
There is no honest universal percentage. For example, an EGO 56V battery manual says packs stored longer than 30 days should be kept below 80°F, free of moisture, at a 30%–50% charge, with a full charge every six months. Other manufacturers call for a full charge and periodic checks. Use the instructions for your pack, not a generic lithium-ion rule.
Store the removed battery and unplugged charger in the dry indoor location the manufacturer allows, away from direct sun, combustible clutter, and objects that could bridge the terminals. Don't charge a cold pack until it reaches the approved charging-temperature range. Record any midwinter check on your calendar.
3. Store the bare mower dry
Clean vents, the deck, wheels, folding joints, and bag. Inspect the blade and safety controls. Fold or stand the mower only if its manual authorizes that position. Vertical storage can save floor space, but it isn't a feature to assume.
If the garage is crowded, use the 4Homes guide to organize a one-car garage for tools and seasonal storage. Keep the mower stable, out of the walking route, and beyond children's reach.
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Final storage checklist
- Mower, engine, battery, and charger instructions checked
- Engine cool; plug wire, cord, key, or battery disconnected
- Deck, vents, wheels, bag, and controls clean and dry
- Blade inspected; sharpening or replacement noted
- Gas fuel route completed exactly as specified, or battery stored at its specified charge and temperature
- Oil, filter, plug, belts, cables, fasteners, and guards checked where applicable
- Fuel and used oil handled in approved containers and disposal channels
- Mower stored dry, stable, and away from flames, sparks, fertilizer, corrosive chemicals, children, and pets
- Spring tasks written on a tag attached to the handle
Add the job to a seasonal home maintenance calendar instead of relying on the first cold night to remind you.
When to call a pro
Stop and use an authorized dealer or qualified small-engine technician when the mower has a fuel or oil leak, persistent gasoline odor, damaged fuel line, failed safety control, bent blade, severe vibration, loose spindle, grinding bearing, cracked deck, drive problem, or electrical fault. Warranty work also belongs with an approved provider.
Battery packs aren't homeowner repair projects. A damaged pack, charger fault, scorched contact, or repeated overheating needs authorized-service guidance. Riding-mower deck lifting, fuel work, and lead-acid battery service may also call for a pro.
Ask the shop to separate routine storage service from repairs and to call before exceeding a written approval amount. Confirm whether parts, blade balancing, carburetor work, pickup, and disposal are included.
Ways to spend less without skipping the work
Buy only after matching the model number. Clean the deck after the last mow, while buildup is manageable, and transport a removable blade to a sharpening shop instead of paying to move the whole mower.
Book repairs in the off-season; a mower that surges or vibrates won't improve in storage. Record the oil, plug, filter, blade, and battery details so you don't buy the same parts twice next year.
Don't replace parts just because a seasonal kit contains them. Inspect first and follow the service interval. But don't try to save a few dollars by straightening a bent blade, opening a lithium pack, washing a paper filter that must be replaced, or storing untreated fuel against the engine instructions.
Frequently Asked Questions
Should I drain the gas from my lawn mower for winter?
Only if the mower or engine manual calls for empty storage. Some manufacturers direct owners to run the system dry; others specify fresh fuel treated with the approved stabilizer and circulated through the fuel system. Don't mix methods or treat old gasoline as fresh.
Can I leave a lawn mower battery in the garage all winter?
Only when the battery manual allows the garage's temperature and moisture conditions. Remove a detachable pack, store it at the maker's specified charge level, protect its terminals, and keep the charger unplugged unless the instructions require charging. A garage that freezes or gets damp may be outside the allowed range.
Do I need to change lawn mower oil before storage?
Change it when the engine's maintenance schedule says to. Use the specified oil and amount, and don't overfill. Some engines use a check-and-add design, so a blanket annual drain recommendation can be wrong for the model.
Is it safe to store a lawn mower upright?
Only if the manufacturer designed and approved the mower for vertical storage. Otherwise, fuel, oil, battery position, controls, or the folding handle may make upright storage unsafe or damaging. Use the listed storage position on a dry, stable surface.