Gas Chainsaw: Won't start

The chainsaw engine needs gas, compression and spark in order to start. First, make sure there's fresh gas in the tank-old gas accumulates water and burns poorly. Replace the fuel if it's old. Add fuel stabilizer to the gas when you refill the tank to help keep the fuel fresh.

If the fuel is fresh, check for and replace cracked fuel lines. Air enters the carburetor instead of fuel when the fuel lines have cracks. If the fuel lines are okay, you may need to rebuild or replace the carburetor because a dirty carburetor won't supply the engine with fuel.

Next, disconnect the spark plug wire and remove the spark plug. If you see deposits or corrosion on the electrodes, replace the spark plug.

Finally, to check for compression, remove the spark plug, press your thumb over the opening and pull the starter cord. If you don't feel air pushing from the cylinder, it's likely that the piston rings need to be replaced. (For an accurate compression reading, use a compression gauge.)

gas chainsaw

These repairs may help solve your gas chainsaw problem

Rebuild the chainsaw carburetor

Rebuild the chainsaw carburetor

Rebuild kits are available for most carburetors. The kit contains essential components for rebuilding a carburetor, such as diaphragms, seals and gaskets. You can sometimes fix a fuel supply problem by dismantling and cleaning a carburetor. Use the kit to rebuild the carburetor after cleaning it.

February 1, 2014
By Lyle Weischwill
How to rebuild a chainsaw carburetor

A clogged carburetor is one reason a chainsaw won't start. This repair guide gives step-by-step instructions for rebuilding a chainsaw carburetor, which is a cost-effective alternative to replacing it.

Repair difficulty
Time required
 30 minutes or less
Read more
Replace the chainsaw carburetor

Replace the chainsaw carburetor

The carburetor mixes air and gasoline in the proper proportions to create a combustible gas. If the engine starts and then sputters, or doesn't start at all due to lack of fuel, you might need to replace carburetor. It's often more cost effective and practical to replace the carburetor rather than rebuild it.

February 1, 2014
By Lyle Weischwill
How to replace a chainsaw carburetor

If your chainsaw struggles to start or won't start at all, the carburetor could be clogged or its gaskets could be worn. This repair guide gives step-by-step instructions for replacing a chainsaw carburetor in less than 30 minutes.

Repair difficulty
Time required
 30 minutes or less
Read more
Replace the chainsaw fuel lines

Replace the chainsaw fuel lines

Fuel lines become brittle over time and can crack or tear. Replace a fuel line that's brittle or damaged. Be careful to install new fuel lines on the engine the same way the original fuel lines were configured.

February 1, 2014
By Lyle Weischwill
How to replace chainsaw fuel lines

If your chainsaw doesn't start even though it has plenty of gas, the engine might not be getting fuel because a fuel line is clogged or cracked. This DIY repair guide shows how to replace chainsaw fuel lines in 30 minutes.

Repair difficulty
Time required
 30 minutes or less
Read more
Symptoms for gas chainsaws
Main causes: stale gasoline, cracked fuel lines, dirty carburetor, damaged spark plug, worn piston rings
Main causes: bad gas, engine needs tune up, cracked fuel lines, dirty carburetor
Main causes: cracked fuel lines, leaky carburetor seals, damaged fuel tank cap, cracked fuel tank
Repair guides for gas chainsaws

These step-by-step repair guides will help you safely fix what’s broken on your chainsaw.

February 1, 2014
By Lyle Weischwill
How to replace a chainsaw carburetor

If the engine won't start even though there's fuel in the chainsaw, the carburetor could be the problem. Sometimes, it's easier to replace the carburetor than to clean it and rebuild it. Follow these steps to do the job yourself in about half an hour.

Repair difficulty
Time required
 30 minutes or less
February 1, 2014
By Lyle Weischwill
How to rebuild a chainsaw carburetor

If your chainsaw isn't running well, a dirty carburetor could be the problem. You can take it apart, clean it and rebuild it, using a carburetor rebuild kit. This repair guide takes you through the process.

Repair difficulty
Time required
 30 minutes or less
February 1, 2014
By Lyle Weischwill
How to replace chainsaw fuel lines

The fuel line on a chainsaw becomes brittle over time and can crack. Replacing it doesn't require a lot of DYI experience. These instructions show you how.

Repair difficulty
Time required
 30 minutes or less
Articles and videos for gas chainsaws

Use the advice and tips in these articles and videos to get the most out of your chainsaw.

May 1, 2015
5 tips for a hard-to-start chainsaw
By Sears PartsDirect staff

These tips may help you get your hard-to-start chainsaw running.

March 1, 2015
How to store a chainsaw between seasons
By Sears PartsDirect staff

Put away your chainsaw the right way so it's ready the next time you need firewood.

March 1, 2015
How to replace a chainsaw oil pump video
By Sears PartsDirect staff

Oil leaking from your chainsaw often means the oil pump has failed. This video shows how to install a new chainsaw oil pump.