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How to Winterize Small Gas Engines

A weed wacker lying in an early snow.

Winter is upon us, and there’s a good chance you won’t need that weed wacker for a while. You might know someone who’s had the frustrating experience of putting away a perfectly good piece of gas-powered equipment in the fall only to find it not starting up again in the spring. What gives? The trick is to winterize small gas engines properly. Doing so can help extend their overall lifespan and improve reliability at the start of the next season.

Here we’ll run through the basics of winterizing small gas engines, but remember to consult your owner’s manual and follow all recommendations found there as well, especially around issues of safety.

Keeping It Clean

The first step is to clean the equipment and take care of routine maintenance items. If you’ve got a pressure washer, great — just watch out for any sensitive electrical components. Look closely for any loose, broken or otherwise worn parts, such as belts that need replacement or repairing during the down season. This is a good time to replace your air filter and inspect your spark plugs. While you’re at it, look beyond the engine at the whole unit: grease the fittings, check the battery and inspect for other damages or normal wear and tear. You’ll definitely thank yourself later.

Sludgefest How to Winterize a Small Gas Engine

The next step is a good old-fashioned oil change. Frequent oil changes are the cornerstone of any engine maintenance, but when it comes to winterizing small engines, it’s especially important to remove old oil, as it can contain small particles and contaminants that may be corrosive to the system if they’re left sitting for long periods of time. Nothing tricky here — just perform your standard oil drain and change according to your owner’s manual using the properly weighted oil. And of course, don’t neglect to change the oil filter while you’re at it.

Gunk Collectors

Mitigating the effects of stagnant fuel in the system is critical to winterizing a small gas engine properly. Condensation or rust issues can arise in a tank that isn’t completely full, and the ethanol in gasoline can gum up components of the fuel delivery system if the gas is left sitting. Leaving this issue unattended will cause starting trouble and require repairs in the future, guaranteed.

Start by removing all fuel from the tank and running the engine until it sputters out and the fuel has cleared the lines. Then take a few ounces of high octane gasoline mixed with a fuel stabilizer and pour it back into the tank. Again, run the engine until all the fuel is gone. Check to see if your engine has a carburetor with a fuel bowl containing any residual gas to be drained (they often have a drain plug).

Once that’s done, remove the spark plug, squirt a little oil onto the cylinder and (with the spark plug still removed) slowly pull the start cord or otherwise attempt to get the piston moving a few times to coat the chamber with the oil. Be sure to cover the equipment and store it in an area that’s safe from harsh weather and curious critters.

Now you can enjoy your winter knowing that your equipment is just a quick fill-up and inspection away from running in the spring.

Check out all the small engine, lawn & garden parts and accessories available on NAPA Online, or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on how to winterize small gas engines, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

Photos courtesy of Blair Lampe.


Blair Lampe View All

Blair Lampe is a New York-based professional mechanic, blogger, theater technician, and speechwriter.  In her downtime she enjoys backpacking wherever her boots will carry her, rock climbing, experimental theatre, a crisp rosé , and showering love on her 2001 Sierra truck.

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