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1Scan for outdated or missing drivers - takes under a minute2Clear out junk files and repair common Windows errors3Fix the driver behind crashes, sound loss and screen glitchesThe safest way to winterize a lawn mower is to identify its exact model and engine type, then follow that mower’s operator manual for fuel, oil, tipping, blade, and battery instructions. Gasoline walk-behind, riding or zero-turn, and battery mowers do not share one universal storage procedure. Use the checklist below as a planning guide, but let the mower manual, engine manual, stabilizer label, and battery-maker instructions control whenever they differ.
1. Identify the mower before doing any maintenance
Find the model and serial number on the mower and locate the current operator manual. The required steps can change with the engine, fuel system, deck design, battery chemistry, and storage period. Troy-Bilt describes its walk-behind end-of-season directions as general guidance that remains model dependent; the same caution applies to other manufacturers.
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- Gasoline walk-behind: check the engine maker’s fuel and oil directions as well as the mower maker’s instructions. The manual should also specify how to tip the mower, disconnect the spark-plug lead, remove the blade, and clean beneath the deck.
- Riding mower or zero-turn: use the riding-mower manual for fuel-system preparation, battery removal or charging, parking, and any hydraulic or deck requirements. A zero-turn may require a longer engine run after adding stabilizer than a walk-behind mower.
- Battery mower: identify whether the battery is lead-acid, lithium-ion, or another chemistry. Storage temperature, charge level, charger use, and whether the battery should remain in the mower are product-specific.
Do not drain fuel, add stabilizer, change oil, tip the deck, remove a blade, or connect a charger until the manual confirms the correct procedure. Keep the operator manual available while you work; model-specific warnings often cover steps that a generic checklist cannot.
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2. Make the mower safe to service
Move the mower to a stable, well-ventilated work area outdoors or in another location approved by the manufacturer. Shut the engine off, remove the key where fitted, and wait until the engine, muffler, and other hot surfaces have cooled completely.
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- For a gasoline mower, follow the manual’s procedure for disconnecting the spark-plug lead before cleaning, inspecting the blade, or doing other work near moving parts.
- For a battery mower, remove the battery and, where the product uses one, the fuse key or safety key if the manual directs you to do so.
- Prevent accidental starting. Keep hands, feet, loose clothing, and tools away from the blade and drive system. Never reach under a deck to pull out packed grass.
- Use the mower’s specified lifting or tipping position. There is no safe tipping direction that applies to every model; tipping a mower incorrectly can put oil or fuel into the air filter, muffler, or other parts.
Briggs & Stratton’s storage directions call for removing the spark-plug lead before washing away clippings. Troy-Bilt similarly emphasizes blade safety and model-specific deck-cleaning instructions. Follow those manufacturer procedures rather than improvising a position or restraint.
3. Clean the deck, engine, and controls
Grass, leaves, and damp soil left on the machine hold moisture against painted and bare-metal surfaces. They can also block cooling passages and hide cracks or loose hardware. Brush or scrape away debris from the deck, wheels, discharge area, and engine exterior.
- Use a wooden implement or another tool approved by the manual to loosen material under the deck; do not use your hands or feet.
- Clear cooling fins, air-intake screens, recoil-starter areas, and belt guards without forcing debris into openings.
- Clean control levers, cables, and height-adjustment mechanisms so corrosion or packed grass cannot restrict movement.
- If the manual permits washing, keep water away from electrical connections, air-filter openings, bearings, and the muffler. Allow the mower to dry fully before storage.
After cleaning, inspect the underside of the deck and the engine area with a light. Look for cracks, bent metal, oil or fuel leaks, loose fasteners, damaged guards, and wire insulation that has been cut or rubbed through.
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Winter storage is a convenient time to perform maintenance that the service schedule already calls for, but not every seasonal task is mandatory for every mower. Use the specified oil type, capacity, filters, spark plug, and replacement parts for your model.
Oil and filter service
Change engine oil if the operator manual or maintenance schedule calls for it before storage. Drain and refill on a level surface, with the engine warm only when the manual permits that procedure. Use the exact oil grade and quantity listed for the engine; overfilling can cause its own starting and lubrication problems.
Some walk-behind procedures use a siphon pump to remove oil. If your manual allows suction removal, use a pump intended for mower oil and collect the used oil for recycling or disposal under local rules. Do not substitute a fuel-transfer device unless it is rated for oil and the manual permits it.
Air filter and spark plug
Inspect the air filter and service or replace it according to the engine instructions. A clogged or damaged filter can make spring starting difficult and may allow abrasive dirt into the engine. Check the spark plug for fouling, wear, or a damaged insulator; replace it only with the specified type and gap.
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Blade, deck, and drive components
Inspect the blade for cracks, bends, excessive wear, and missing sections. Sharpening or replacement is appropriate only when the blade and the mower manual permit it. A blade-removal tool or sharpening kit can help with this work, but the tool does not replace the model’s locking, torque, and reinstallation instructions. Replace damaged guards, wheels, belts, cables, and fasteners with parts specified for the mower.
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- Fixes rough running and hard-to-start engines: Breaks down gum and varnish that cause rough running, hard starts, sputtering, and no-start issues in small engines, helping restore performance quickly
- Cleans carburetors and fuel system: Works through the fuel system to clean carburetors, fuel injectors, and internal components, functioning as a small engine carb cleaner without requiring disassembly
- Removes water and combats ethanol fuel effects: Helps eliminate water in the fuel system and combats the effects of ethanol-blended fuels, including E15, which can contribute to rough running, stalling, and starting issues
- Designed for lawn mowers and small engine equipment: Ideal for use in lawn mowers, trimmers, chainsaws, snow blowers, generators, and other 2-cycle and 4-cycle engines
- Easy-to-use fuel treatment: Add to fresh gas and run the engine to circulate through the system, treating up to 20 gallons and helping restore smooth operation in small engines affected by fuel-related issues
If you find a structural crack, a badly bent blade, a fuel leak, or uncertainty about blade removal, stop and use the manufacturer’s dealer or service center. A clean mower with an unresolved safety defect is not ready for storage.
5. Prepare gasoline mowers using the manual-approved fuel method
Gasoline storage instructions conflict among manufacturers, so do not combine steps from different brands. The two common approaches are treated fuel and fuel draining. Which one is correct depends on the mower, engine, fuel system, expected storage period, fuel type, and the manufacturer’s current instructions.
| Approach | What the cited instructions say | Important limits |
|---|---|---|
| Treated fuel | Briggs & Stratton recommends fresh fuel with the correct stabilizer, filling the tank, and running the mower for a few minutes so treated fuel circulates. A Husqvarna zero-turn guide specifies running for at least 10 minutes after preparation. | Those run times belong to those specific instructions. Use the stabilizer label ratio and your own manual rather than adopting one universal duration. |
| Seasonal treated fuel | Troy-Bilt discusses treated fuel for storage periods of 30 to 90 days on applicable walk-behind models. | The range is part of Troy-Bilt’s model guidance, not a guarantee for every mower, fuel, or stabilizer. |
| Drain fuel | Some Briggs & Stratton instructions identify draining as appropriate in particular circumstances. Other manufacturer instructions call for draining and may also require running the engine until it stops or otherwise clearing the system. | Drain only when your mower or engine manual calls for it. Do not switch methods because another manufacturer uses a different one. |
| Long-term STIHL storage | STIHL’s US winterizing guide states: “STIHL doesn’t recommend mowers be stored for long periods of time with fuel, even if a stabilizer is added.” | The statement applies to STIHL’s mower guidance; it is not a universal rule for every gasoline mower. |
If your manual allows treated fuel
- Use fresh gasoline of the type and ethanol content approved for the mower. Do not mix fuel grades or additives that the manual excludes.
- Measure a small-engine fuel stabilizer at the ratio printed on its label. Troy-Bilt names STA-BIL as an example of the category; products are not automatically interchangeable.
- Add the treated fuel to the tank as directed. Briggs & Stratton’s cited procedure uses a full tank, while another model may specify a different level.
- Run the engine for the time stated by your manual so treated fuel reaches the carburetor or fuel-injection components. The cited Briggs guidance says a few minutes; the cited Husqvarna zero-turn guidance says at least 10 minutes.
- Shut the engine off, let it cool, and inspect for leaks before moving the mower into storage.
Briggs & Stratton says gasoline can begin to degrade in as little as 30 days, potentially clogging the fuel system and causing starting problems. That figure appears on its page updated January 13, 2026; it is a manufacturer warning, not a universal shelf-life guarantee or an independent laboratory result.
If your manual requires draining
- Work outdoors or in a location explicitly approved for fuel handling, away from flames, cigarettes, heaters, pilot lights, switches that may spark, and other ignition sources.
- Use an approved fuel container and the drain method specified for the mower. A siphon pump may be suitable for some operations, but use only equipment rated for gasoline and approved by the instructions.
- Follow the manual’s direction about running the engine after draining. Some procedures call for running until the engine stops; others specify a different way to clear the fuel system.
- Close caps and valves as directed, wipe spills immediately, and handle the fuel according to local disposal and storage rules.
Keep gasoline vapors out of unsafe storage areas
Husqvarna warns against storing an engine with fuel in the tank indoors or in a poorly ventilated place where vapors could reach a flame, spark, or pilot light. Even when a manual permits treated fuel, the storage location must meet the manufacturer’s ventilation and fire-safety requirements. Never keep a fuel container beside a furnace, water heater, extension-cord connection, or other possible ignition source.
6. Store battery mowers and batteries according to chemistry
A battery mower needs a separate storage plan. Removing the battery, charging it, or leaving it connected can each be correct for some products and wrong for others. Read both the mower manual and the battery or charger instructions.
| Battery guidance example | Storage direction | Qualification |
|---|---|---|
| STIHL battery mower | Remove the battery and fuse key, clean the mower, lubricate moving parts where the instructions specify, and store the mower in a cool, dry place. | These are STIHL product steps, not universal instructions for every battery mower. |
| Husqvarna lead-acid battery | Store the battery fully charged, keep it above 5°C, and recharge it every two months. | The temperature and recharge interval come from Husqvarna’s battery guidance. |
| Husqvarna lithium battery | Consult the battery maker’s instructions for charge level, temperature, and maintenance during storage. | Lithium batteries do not automatically follow lead-acid charging intervals. |
Battery removal and location
Place a removed battery in the location specified by its maker, protected from moisture, extreme temperatures, and accidental short circuits. Keep terminals from contacting keys, tools, loose hardware, or other conductive objects. Do not use a charger, extension cord, or storage mode that the battery maker does not approve.
Temperature and charging decisions
Do not infer a safe temperature or charge percentage from another battery’s chemistry. Lead-acid maintenance can require periodic recharging, while lithium products may specify a particular partial-charge range and prohibit charging below a stated temperature. If the mower and battery manuals disagree, contact the manufacturer or an authorized service center before storage.
7. Protect the mower during storage
Choose a clean, dry storage space protected from rain, condensation, and direct weather exposure. STIHL specifies a cool, dry, preferably frost-free location. Husqvarna’s zero-turn guidance calls for clean, dry storage and says a cover can provide additional protection.
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- PRESERVES FUEL: This fuel stabilizer ensures keeps gasoline fresh for up to 24 months for storing vehicles that are not in use, boats, outdoor power equipment during winter months, or stocking up on fuel.
- PREVENTS CORROSION: Safeguard your engine & fuel system from the detrimental effects of both ethanol & non-ethanol fuels. Maintaining the integrity of fuel system components, it ensures optimal performance & longevity, promoting a healthier fuel system.
- EASY STARTS: Guarantees quick & easy starts for your equipment & vehicles, providing peace of mind when storing them. With its reliable performance, you can confidently store your items, knowing they will start smoothly whenever needed.
- DIRECTIONS: Pour contents directly into the fuel tank before adding gasoline. Use 1 oz of STA-BIL Storage for every 2.5 gallons of gas. After adding the fuel, run the engine for 5 minutes to treat the entire fuel system.
- EXPIRATION DATE: 2 years from the opening of product, or 5 years from date of production (5-digit code on the back of the bottle; read as YYDDD). YY indicates the year of production. DDD represents the number of the day of that year of production.
- Store the mower on a stable surface where it cannot roll, tip, or block an exit.
- Use a breathable cover approved for the mower rather than wrapping a damp machine in plastic, which can trap condensation.
- Keep the deck and engine completely dry before covering.
- Apply rust protection only to the parts and in the manner named by the manual. Keep oil, spray, and corrosion coatings away from belts, brake surfaces, electrical contacts, air intakes, and other components where contamination could cause a fault.
- Keep gasoline, batteries, chargers, and oily rags separated from heat sources and ignition points. Follow local fire and disposal requirements.
For a riding or zero-turn mower, set the parking brake and follow the manual’s parking, deck-lowering, and key-removal instructions. Do not rely on a cover to compensate for a leak, damaged guard, or unsecured machine.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.8. Use a model-specific decision checklist
Gasoline walk-behind mower
- Record the model and read the operator and engine manuals.
- Cool the mower, disconnect the spark-plug lead as directed, and clean the deck and engine with the specified safe-tipping method.
- Inspect the blade, guards, wheels, cables, air filter, spark plug, oil, and fasteners; complete only the maintenance the schedule requires.
- Choose treated fuel or draining only if the manual calls for that method, then follow its exact stabilizer ratio, run time, container, and disposal directions.
- Store clean and dry in the manufacturer-approved location.
Riding mower or zero-turn
- Use the riding-mower manual for fuel preparation, battery service, parking, and deck position.
- Clean the deck, engine compartment, cooling areas, and controls without directing water into electrical or intake openings.
- Inspect belts, guards, tires, steering or drive controls, blade assemblies, and leaks; replace only specified parts.
- If treated fuel is allowed, use the manual’s required circulation time. The cited Husqvarna zero-turn guidance calls for at least 10 minutes, but that timing should not be transferred to another model.
- Park securely, remove keys as directed, and cover the dry machine if the manufacturer recommends it.
Battery mower
- Identify the battery chemistry and read the mower, battery, and charger instructions.
- Remove the battery and fuse key when required, then clean and inspect the mower.
- Set the battery’s charge and storage temperature according to its maker; do not apply lead-acid intervals to a lithium battery without confirmation.
- Store the mower and battery in clean, dry locations that meet the manufacturer’s temperature and ventilation requirements.
9. Common winterization mistakes and corrections
Using another brand’s fuel rule
Mistake: draining every mower because one guide recommends draining, or adding stabilizer to every mower because another guide recommends treated fuel.
Correction: start with the exact mower and engine manual. Manufacturer instructions differ, and STIHL specifically advises against long-term storage with fuel even when stabilized.
Running the wrong amount of time
Mistake: assuming “a few minutes” and “10 minutes” are interchangeable.
Correction: use the duration tied to your model’s procedure. Briggs & Stratton and Husqvarna publish different examples, so do not blend them.
Cleaning with the machine energized
Mistake: reaching beneath the deck while the spark-plug lead, battery, or fuse key remains connected.
Correction: cool the machine and isolate the starting system exactly as the manual directs before removing debris.
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Mistake: covering wet grass residue or condensation with plastic.
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- PRESERVES FUEL: This fuel stabilizer ensures keeps gasoline fresh for up to 24 months for storing vehicles that are not in use, boats, outdoor power equipment during winter months, or stocking up on fuel.
- PREVENTS CORROSION: Safeguard your engine & fuel system from the detrimental effects of both ethanol & non-ethanol fuels. Maintaining the integrity of fuel system components, it ensures optimal performance & longevity, promoting a healthier fuel system.
- EASY STARTS: Guarantees quick & easy starts for your equipment & vehicles, providing peace of mind when storing them. With its reliable performance, you can confidently store your items, knowing they will start smoothly whenever needed.
- DIRECTIONS: Pour contents directly into the fuel tank before adding gasoline. Use 1 oz of STA-BIL Storage for every 2.5 gallons of gas. After adding the fuel, run the engine for 5 minutes to treat the entire fuel system.
- EXPIRATION DATE: 2 years from the opening of product, or 5 years from date of production (5-digit code on the back of the bottle; read as YYDDD). YY indicates the year of production. DDD represents the number of the day of that year of production.
Correction: clean and dry the mower first, then use the manufacturer-approved cover in a dry storage area.
Charging a battery by habit
Mistake: leaving every battery on a charger or storing every battery fully discharged.
Correction: follow the chemistry-specific battery and charger instructions. Husqvarna’s cited lead-acid guidance calls for a full charge and recharge every two months, while its lithium guidance directs owners to consult the battery maker.
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Ignoring a defect until spring
Mistake: storing a mower with a cracked deck, bent blade, fuel leak, damaged guard, or uncertain repair.
Correction: replace specified parts or have the mower inspected by the manufacturer’s dealer or service center before storage. Winter is not a safe place to postpone a defect that affects starting, fuel containment, or blade control.
10. When professional service is the better option
Use a dealer or qualified service center when the model manual is unavailable, the fuel system leaks, the blade cannot be removed safely, a structural component is damaged, the mower has an electrical or charging fault, or the battery shows swelling, overheating, or physical damage. Bring the model and serial information and describe the storage period and the fuel or battery condition. Do not attempt to open a damaged lithium battery or bypass a safety switch.
A professional can also confirm whether a particular mower should be drained, stored with treated fuel, or prepared with a model-specific procedure that is not obvious from a generic checklist. That confirmation is especially valuable when the mower has a replacement engine, aftermarket fuel components, or a battery and charger from different product families.
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