FUEL SYSTEM

If a mower, pressure washer or other small engine ran well before storage but now struggles to start, the fuel is one possible place to look. Gasoline does not stay fresh indefinitely, and fuel-system problems can develop while equipment sits unused.

What changes while fuel sits?

Gasoline deteriorates and oxidizes during storage. Deposits can develop and obstruct small fuel-system passages. Honda also explains that water contamination in ethanol-containing gasoline can contribute to corrosion and starting or running problems. The rate of deterioration varies with fuel formulation and storage conditions, so there is no single guaranteed shelf life for every situation.

What symptoms might you notice?

Hard starting and poor running can be associated with deteriorated fuel, but those symptoms are not a diagnosis. A spark-plug problem or another fault can look similar. Tell your service provider how long the equipment has been sitting and whether the gasoline came from an older storage container. That history helps guide troubleshooting.

Does stabilizer fix old gasoline?

No. Fuel stabilizer is a preventive measure used with fresh fuel, not a way to restore fuel that has already deteriorated. If contamination or deposits have developed, fuel-system service may still be necessary. Follow the product label and your engine’s storage instructions rather than adding extra stabilizer in the hope of correcting a no-start problem.

Build a simple fuel routine

Buy quantities that fit your actual usage, label your fuel container with the purchase date and keep it closed in an appropriate storage location. Use an approved fuel container and the gasoline specified by the equipment manufacturer. Consult the manual before seasonal storage: different engines may require different procedures. Never assume that a storage method for one machine applies to every mower, trimmer or pressure washer.

When should you schedule maintenance?

If your equipment still will not start or run properly, request diagnosis instead of repeatedly trying to start it. Stop using equipment with a visible fuel leak. Fuel handling should take place away from heat, flames and sparks, with the engine off and cool. Never run a gasoline engine inside a garage, even with the door open.