How to Winterize a Chainsaw

Stabilize the gas and the engine

• Add a fuel stabilizer to your two-stroke gas mixture and fill the chainsaw’s gas tank.
• Run the engine until the machine is warm to coat the entire engine with the stabilized mix.

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Drain the gas

• Dump the gas back into your tank
  • Note: because the gas is stabilized, you can use it next season.
• Pump your primer bulb while emptying the gas to flush all the gas out.

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Re-start the engine

• To remove as much gas from the engine as you can, start the engine back up and let it die out.
• Continue to start it up after it dies until it won’t start anymore.
  • Pro Tip: Giving the chainsaw a shake or two while it’s idling will help move any leftover gas along.

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Clean or replace the filter

• Open up the case and check the filter.
• If it looks dirty, clean it gently with a shop towel or brush.
• If it’s damaged or too caked with dust, replace it before starting it back up next season.
  • Pro tip: Filters are specific to each engine. If you’re replacing one, make sure it’s the correct filter for your engine.

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Disconnect the spark plug

“You can disconnect the spark plug wires to prevent any accidental starts,” Bob Cain from Bob’s Small Engine Repair says. Removing the spark plug when you winterize a chainsaw can also prevent corrosion while in storage.

• With the case removed, locate the spark plug. It will be on the top or side of the engine.
• Disconnect the spark plug wire.
• Use a rag to clean around the spark plug to prevent any debris from falling into the combustion chamber.
• Use a socket wrench to turn the spark counterclockwise to loosen and remove.

Clean the engine

• Clean off the coil fins and any grunge that might be inside the case.
  • Pro Tip: A chip brush is the perfect tool for this job.

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Remove bar and chain

• Open the chain sprocket cover and remove the bar and chain.
• Clean the sprocket and all the grime around it.
• Clean the bar and chain with a biodegradable corrosion inhibitor to keep the chain and bar from rusting. Then, reassemble the chainsaw.

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Clean the chainsaw

• Wipe the entire powerhead down with a slightly damp cloth.

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Cover and store the chainsaw

When you winterize a chainsaw, Cain recommends always storing it in its case. You’ll also want to keep it in a covered, dry location that’s out of the elements. “Store it in your garage, preferably on a top shelf, out of reach of children,” Cain says. When you need it the following season, fill it with gas and it’s ready to go.

FAQ

What happens if you don’t winterize a chainsaw?

More than likely, when you go to use it next season, it won’t start. Gas left in the tank will destabilize over the winter, which can lead to issues with starting. Even if it does start, running your chainsaw with old gas and oil will gum up the carburetor and lead to increased chainsaw maintenance and lower performance.

Do all chainsaws need to be winterized?

If you live in a mild climate that does not experience winters, you do not necessarily have to winterize your chainsaw. However, if your chainsaw will sit unused for an extended period of time, it’s a good idea to follow the steps to winterize before storing.

Can you leave gas in a chainsaw over the winter?

No, you should not let the gas sit in an idle chainsaw for months at a time. Even if the chainsaw starts up again in the spring with the destabilized gas, it will gunk up the carburetor, resulting in more problems. See steps 1-3 above for using a fuel stabilizer and draining the gas before putting your chainsaw away.

About the Expert

Bob Cain is the owner of Bob’s Small Engine Repair in Three Rivers, Massachusetts. He has over 25 years of experience fixing small engines.