Why Your Chainsaw Won’t Stay Running: How To Fix + Maintenance Tips

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Ever been in that situation where your trusty power tool goes from running smoothly to leaving you scratching your head in frustration? Well, I’ve been there too, and it’s not a fun experience.

So, I’ve put together this article to help you figure out why your cherished chainsaw has decided to play hard to get. Let’s dive in and unravel the mysteries behind why it won’t stay running.

The Most Common Causes of Chainsaw Issues

Clogged carburetors, damaged spark plugs, and flooded engines are the most common reasons a chainsaw can’t stay running. Yet it’s still tricky to come up with quick fixes to these common problems without knowing what could have caused engine damage in the first place.

#1: Starting Problems

Excessive tension in the saw caused by fuel build-up is often the culprit behind starting problems in your machine. However, it’s still advisable to pull the cord a couple of times before proceeding with other troubleshooting procedures.

starting a chainsaw

#2: Cold Weather

Seasonal changes in weather and temperature can contribute to malfunctioning machines. Pulling the choke can help the machine restart and adapt, especially in cold weather. 

#3: Hitting the Throttle For an Extended Period

Running the throttle more than once or thinking that holding it for a long time will do the trick is a common pitfall in working with chainsaws. Thus, avoid incorrectly hitting the throttle to avoid damaging the engine and prompting it to stop running. 

Chainsaw Running Issues and How to Fix Them

Issue #1: Old or Bad Fuel

Contaminated fuel can cause engine issues. This boils down to the evaporated volatile agents that happen after a couple of weeks from the machine’s purchase. Blocked fuel filters make it difficult for engines to acquire enough fuel to run. 

Solution: Refuel With Fresh and High-Quality Oil

If the problem is bad oil, replace such with fresh oil. The proper fuel and fresh gas ratio will prevent interference on your machines, so I recommend following a precise ratio. 

Issue #2: Spark Switch/Plugs Problems

A spark plug helps initiate combustion in the machine, specifically in the air-fuel mixture area, and it often gets worn out easily brought about by use. Normally, a spark plug erodes quickly, especially with frequent use.

chainsaw spark plug

Solution: Check For Bad Spark Plug

Check for sparks on the spark plug by touching the metallic part with another wire. If the electrodes don’t produce sparks, it’s more likely that there are plug problems, and it’s time for a new spark plug. 

Issue #3: Dirty or Clogged Carburetor

A bad carburetor is frustrating for woodworkers because it means an expensive replacement. It’s the part that fuels gas into the combustion chamber, making it vital to every chainsaw. 

When you leave bad fuel on the fuel tank and let it sit there for a long time, chances are it leaves the carburetor clogged. 

Solution: Clean or Replace the Carburetor

Keep a carb cleaner and carb kit handy to keep your engine well maintained and prevent sticky substances from forming. Invest in a carb kit packed with gaskets, O-rings, and replacement parts. 

If normal cleaning won’t work, purchasing a whole carburetor is the only solution for your faulty chainsaw

Issue #4: Flooded Engine

Overdoing a fuel pump push will prompt your engines to get flooded. One telltale sign of flooded engines is moist in the spark section. 

checking a chainsaw's flooded engine

Solution #1: Drain the Fuel

Leave your chainsaw sitting for 15 to 20 minutes to give enough time for the bad fuel to evaporate and dry out. This fix works best for optimum fuel and mildly flooded chainsaws.  

Solution #2: Adjust the Carburetor

Different chainsaw brands require different carburetor calibration settings. Adjust the high-speed screw if the chainsaw’s engine doesn’t rev up or reach full power. 

If the chainsaw engine stalls, and fails at low speed, calibrate the low-speed screw. Hence to achieve proper airflow, adjusting the idle screws is also recommended. 

You Might Be Interested In: Guide to Adjusting Your Poulan Chainsaw Carburetor

Issue #5: Bad Recoil Starter

The recoil starter is one of the vital parts of a chainsaw’s engine. Failure for the spring to recoil onto the pulley compromises how the chainsaw runs, resulting in engine stalls. 

Often too, the spring clip is put backward, which blocks the rope from pulling, and this is a common mistake most users make. 

Solution: Replace With a New Recoil Starter Assembly

Broken starter ropes or having one that doesn’t recoil is frustrating, and depending on how bad your starter problem is, getting a new recoil starter assembly is the best fix. Check in with your local hardware when replacing your rewind springs to make sure you get the right one. 

Issue #6: Blocked or Damaged Idle Port

There’s an idle port on chainsaws that keeps it idle. However, you should know that this part deteriorates from continuous use and can get blocked or damaged, leaving the idle port unserviceable. If your chainsaw fails to get in an idle position, it will not run properly. 

fixing chainsaw idle port

Solution: Clean or Replace the Idle Port

Use any solvent such as kerosene or alcohol [1] to clean the blocked or clogged idle port and the idle screw of your chainsaw. 

To maintain a proper idle and keep the chainsaw to stay running, maintaining a precise air fuel ratio, and tweaking the idle ports and screw over time are ideal practices you should do. 

Also, clean the small screen or the spark arrester with a wire brush, which can be another cause of idling problems.

adding fuel to Poulan Chainsaw

Issue #7: Fuel Delivery Problems

Without adequate gas, a chainsaw’s engine will keep stalling. Due to bad gas, a clogged fuel filter often results in trouble in running a chainsaw. This happens when you haven’t used the chainsaw for a long time with the contaminated fuel sitting in the engine. 

Solution: Inspect Fuel Filter and Fuel Lines

To clean the fuel lines and fuel filter, dampen your cloth with a small amount of liquid with gas or kerosene to prevent it from drying out. If the fuel lines look damaged and are too faulty, replace the whole fuel line. 

It’s also recommended staying away from ethanol gas which is the common perpetrator of damaged fuel lines. 

Issue #8: Clogged or Dirty Air Filter

Another common reason why your chainsaw won’t stay running is a clogged air filter. When your air filter is jammed, it deters the air needed to burn the fuel, resulting in too much fuel and depletion of the combustion chamber. 

chainsaw air filter

Solution: Clean Thoroughly or Find a Replacement

Any air filter must be maintained clean, or it will lose its purpose in the first place. Find your chainsaw’s air filter, clean it thoroughly by washing it, and use a small bristle brush to clean off the filter’s edges. 

Some air filters are washable depending on the chainsaw model, but if cleaning doesn’t work, getting a replacement won’t cost you that much either. 

Issue #9: Dirty/Clogged Fuel Tank Vent or Fuel Cap

To allow fuel onto the carburetor, it needs balance amongst the chainsaw pressure. Depending on the model, your chainsaw will have air vents or vented caps, like every part of the machine, which should be maintained. Also, never start your chainsaw without the fuel cap attached. 

Solution: Inspect the Air Vent

Do a quick test to inspect whether the air vent is causing your chainsaw to stall. Loosen the fuel cap and let enough air get in before starting the chainsaw. If it continues to run, we can conclude that the tank is the culprit. 

fixing chainsaw air vent

Then, refer to your chainsaw manual for the proper cleaning procedure that needs to be done on the air vent. 

Issue #10: Damaged or Clogged Primer Bulb

Primer bulbs allow gas to suck into a cold carburetor through suctions. Before fuel enters the engine, it goes into the primer bulb, so it should always be filled with gasoline.

Solution: Replace the Primer Bulb

Too much exposure can cause the primer bulb material to crack, and if the air escapes, it will prevent the chainsaw from idle. When this happens, replace the primer bulb. 

How to Start Your Chainsaw Properly

Step #1: Place the Chainsaw on the Ground

Remove the chainsaw cover, and make sure you place it on the ground.

Step #2: Push the Brake Chain

Push the chain brake into a forward position so that the chain does not rotate onto the chainsaw bar and becomes active.

hand on chainsaw brake chain

Step #3: Decompress

Engage the smart decompression button of your saw to help it start. All new models are now equipped with this smart start button.

Step #4: Press the Fuel Pump

Keep pressing the pump until you see the fuel to keep the machine operational.

Step #5: Pull the Starter Rope

Hold the top of the chainsaw with your left hand, and place your right foot on the handle before pulling the starter rope slowly.

Chainsaw Maintenance and Care

Observe proper maintenance to keep your chainsaw in excellent condition. 

Loose Nuts

Adjust the loose nuts accordingly to get the chainsaw to stay running properly.

chainsaw loose nuts

Keep the Blade in Check

Observe the blades after every use to know how much sharpening it needs to function properly.

Keep the Parts Lubricated

Always keep the moving parts of your saw well-lubricated to prevent the machine from overheating.

Clean Regularly

Keep your chainsaw out of debris and dirt to avoid build-ups that damage the chainsaw. 

Use High-Quality Gas

Premium gas keeps your chainsaw in good form, but use fuel stabilizers to avoid ending up with bad fuel stuck on your machine for a long. 


Why does my chainsaw stall when I give it gas?

A chainsaw stalls when given gas because of the amount of fuel causing damage to the engine. Procuring extra filters, O rings, and replacement gaskets helps you deal with this common problem. 


When it comes to power tools like chainsaws, maintenance truly reigns supreme. If your brand-new chainsaw seems to sputter or stall, I’d suggest taking a bit more quality time with those user manuals to get acquainted with your trusty machine.

It might sound surprising, but even a bit of ordinary dirt can wreak havoc on the engine, and you wouldn’t want to fork out your hard-earned cash for avoidable repairs. So, let’s keep those chainsaws humming smoothly!

robert headshot

Robert Johnson is a passionate furniture maker & carpenter, sought after for his knowledge on the craft.
You’ve probably seen his down-to-earth wisdom in USA Today, Bobvila, Family Handyman, and The Spruce, where he has shared commentary and guidance on various woodworking topics.

Robert is the brain behind Sawinery, where he aims to share tips, tricks, and a passion for all things carpentry.

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