Why Won’t My Chainsaw Start? 6 Common Causes and How to Fix Them

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Updated in April 2025 | By John

Your chainsaw won’t start You’re not alone. Chainsaw is one of the most popular power tools, but it’s also one of the most common tools that experience problems. There are a few reasons why your chainsaw might not be starting, and in this blog post, we’ll explore some of the most common causes and how to fix them. So if you’re having trouble getting your chainsaw started, read on for some helpful tips!

Why My Chainsaw Won’T Start

Why won’t my chainsaw start?

There are a few possible reasons why your chainsaw won’t start.

Fuel:

Make sure that you have enough fuel in the tank and that the fuel is fresh. Old or stale fuel can cause problems with starting.

Spark:

Check the spark plug and make sure that it is clean and in good condition. A dirty or damaged spark plug can prevent the chainsaw from starting.

Chainsaw chain:

Make sure that the chainsaw chain is properly tensioned. A loose chain can cause the chainsaw to stall.

Chainsaw carburetor:

The carburetor is responsible for mixing the fuel and air in the correct proportions. If the carburetor is dirty or clogged, it can prevent the chainsaw from starting.

If you have checked all of these things and your chainsaw still won’t start, you may need to take it to a qualified chainsaw repair technician.

Why My Chainsaw Won’t Start

Possible Causes

There are a number of possible reasons why your chainsaw might not start. Here are some of the most common:

The spark plug is fouled:
This is the most common cause of a chainsaw not starting. A fouled spark plug means that the electrodes are covered in carbon deposits, which prevent the spark from jumping across the gap. To clean the spark plug, remove it from the chainsaw and use a wire brush to clean the electrodes.

The spark plug gap is incorrect:
The spark plug gap is the distance between the electrodes. If the gap is too wide, the spark will not be strong enough to ignite the fuel. If the gap is too narrow, the spark will be weak and will not be able to jump across the gap. To check the spark plug gap, use a spark plug gap gauge.

The carburetor is dirty:
The carburetor is responsible for mixing the fuel and air in the correct proportions. If the carburetor is dirty, it will not be able to mix the fuel and air properly, which will prevent the engine from starting. To clean the carburetor, you will need to remove it from the chainsaw and disassemble it. Use a carburetor cleaner to clean all of the parts.

The fuel filter is clogged:
The fuel filter prevents dirt and debris from entering the carburetor. If the fuel filter is clogged, it will restrict the flow of fuel to the carburetor, which will prevent the engine from starting. To clean the fuel filter, remove it from the chainsaw and rinse it with warm water.

The fuel is old or stale:
Old or stale fuel can cause problems with starting a chainsaw. The fuel can become contaminated with water or other impurities, which can prevent the engine from starting. To avoid this problem, make sure to use fresh fuel.

The engine is flooded:
If the engine is flooded, it means that there is too much fuel in the cylinder. This can prevent the engine from starting because the spark plug will not be able to ignite the fuel. To clear the flood, turn the chainsaw off and wait a few minutes for the fuel to evaporate. Then, try starting the chainsaw again.

Troubleshooting Tips

If you have checked all of the possible causes and your chainsaw still won’t start, here are some troubleshooting tips:

Try turning the choke on and off. The choke is a valve that restricts the flow of air to the carburetor. When the choke is on, it helps to enrich the fuel mixture, which makes it easier to start the engine. If the chainsaw is still not starting, try turning the choke off.
Try priming the chainsaw. Priming the chainsaw means pumping the primer bulb to force fuel into the carburetor. This can help to start the engine if it is flooded.
Try tapping the spark plug with a wrench. This can help to clear any carbon deposits that may be preventing the spark from jumping across the gap.
If you are still having trouble starting the chainsaw, you may need to take it to a qualified service technician.

Preventative Maintenance

The best way to avoid problems with your chainsaw starting is to perform regular preventative maintenance. Here are some tips:

Clean the spark plug regularly. A dirty spark plug can cause a number of problems, including the engine not starting.
Check the spark plug gap regularly. The spark plug gap should be checked and adjusted as needed.
Clean the carburetor regularly. A dirty carburetor can prevent the engine from starting.
Replace the fuel filter regularly. A clogged fuel filter can restrict the flow of fuel to the carburetor, which can prevent the engine from starting.
Use fresh fuel. Old or stale fuel can cause problems with starting a chainsaw.
Store your chainsaw in a cool, dry place. Storing your chainsaw in a warm, humid environment can cause the fuel to evaporate and the carburetor to become clogged.

Also Read THis: Why Does My Chain Keep Coming Off My Chainsaw

FAQs: Why won’t my chainsaw start?

Why won’t my chainsaw start?

There are a few reasons why your chainsaw might not start. Here are some of the most common causes:

The chainsaw is not getting enough fuel: Make sure that the fuel tank is full and that the fuel line is clear.

The chainsaw is not getting enough air: Check the air filter to make sure that it is clean and free of debris.

The spark plug is fouled: Remove the spark plug and clean it with a wire brush.

The chainsaw is not being primed properly: Follow the manufacturer’s instructions for priming the chainsaw.

The chainsaw is not being choked properly: Choke the chainsaw when starting it in cold weather.

How do I prime a chainsaw?

To prime a chainsaw, follow these steps:

1. Turn the chainsaw off.
2. Pull the choke lever to the choke position.
3. Move the throttle lever to the fast position.
4. Press the primer bulb several times until the fuel flows freely from the carburetor.
5. Release the choke lever and move the throttle lever to the slow position.
6. Start the chainsaw by pulling the starter rope.

How do I clean the air filter on my chainsaw?

To clean the air filter on your chainsaw, follow these steps:

1. Remove the air filter cover.
2. Remove the air filter from the chainsaw.
3. Rinse the air filter in warm, soapy water.
4. Dry the air filter completely.
5. Reinstall the air filter on the chainsaw.

How do I replace the spark plug on my chainsaw?

To replace the spark plug on your chainsaw, follow these steps:

1. Turn the chainsaw off and allow it to cool down.
2. Remove the spark plug boot.
3. Use a spark plug wrench to unscrew the spark plug.
4. Apply a thin coat of anti-seize compound to the threads of the new spark plug.
5. Screw the new spark plug into the cylinder head until it is snug.
6. Reinstall the spark plug boot.

How do I choke a chainsaw?

To choke a chainsaw, follow these steps:

1. Turn the chainsaw off.
2. Pull the choke lever to the choke position.
3. Move the throttle lever to the fast position.
4. Start the chainsaw by pulling the starter rope.
5. Once the chainsaw is running, release the choke lever and move the throttle lever to the slow position.

About The Author

I am John, and I am the creator of this website. I have been in the woodworking industry for about 5 years. I developed my passion for DIY projects around the house when I was in high school. I have discovered a new appreciation for those who have the experience to pass along their expertise. They know what works best and are able to help others. I am proud to be among them.

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