How to Unflood a Chainsaw

A chainsaw is useful for cutting through thick branches and logs but can become flooded if not used correctly. When a chainsaw floods, the spark plug is filled with too much fuel, leading to a rich mixture inside the combustion chamber. This will prevent the chainsaw from starting, as the spark cannot ignite the fuel.

How to Unflood a Chainsaw

Unflooding can be done quickly with the right tools and guidance, allowing you to return to your cutting tasks faster. It also helps prevent further damage from occurring by removing water or excess fuel from the engine. Knowing to unflood a chainsaw can also save you money on repairs and replacement parts. In this blog post, You will learn in detail how to unflood a chainsaw.

Step by Step Processes for How to Unflood a Chainsaw 

Step 1: Inspect the Area 

Make sure the area is safe, and all bystanders are a safe distance away. Carefully remove the fuel from the tank and dispose of it in a safe place. Using both hands, pull the starter rope several times to clear any excessive fuel or oil that may have gotten into the cylinder resulting in a flooded engine. 

Step 2: Remove the Spark Plug

Once you have cleared any excessive fuel, it is time to remove the spark plug. Make sure that the chainsaw is completely off before removing it. The spark plug should be located between the cylinder and the muffler. Using a wrench, unscrew the spark plug and set it aside in a safe location.

Step 3: Prime the Chainsaw

Take a few drops of clean fuel and carefully put them into the spark plug hole. Make sure to do this slowly, so that the fuel does not leak out or overflow from the hole. Then, replace the spark plug and turn on your chainsaw. 

Step 4: Start the Chainsaw

Once you have replaced the spark plug, pull the starter rope several times until you hear a low roar of the engine. If it does not start after a few pulls, repeat steps 2 and 3 again until it starts. Once you have successfully started your chainsaw, let it idle for a few minutes before shutting it off. This will allow any excess fuel that may have been present to burn out. 

Step 5: Check Your Chainsaw

Once you have finished using your chainsaw, check the spark plug and fuel tank for any leaks or improper connections. If everything looks good, your chainsaw is ready to be used again. 

Check the Spark Plug

By following these steps, you can successfully unflood your chainsaw and get back to work in no time. Make sure you always keep your chainsaw properly maintained and inspected for potential problems.

Tips for How to Unflood a Chainsaw 

  1. Make sure to check all parts of the chainsaw before trying to unflood it and ensure they are in good working condition.
  2. Carefully inspect the fuel lines, filters, and spark plug for any blockages or damage that may be present. If you notice any issues with these parts, then it is best to replace them.
  3. Wear protective gloves and eyewear when working on the chainsaw to protect your hands and eyes from any sharp edges or debris that may be present.
  4. Before attempting to start the chainsaw, ensure it is in a secure area away from flammable items and with adequate ventilation.
  5. Follow all safety instructions the manufacturer provides when using the chainsaw, and take extra care to ensure that you are operating it safely at all times.

If you follow these safety tips, you can be sure to unflood your chainsaw in a safe and effective manner. Keep these tips in mind when working on or around a chainsaw.

What Are Some Common Causes of a Chainsaw Flooding?

Chainsaw flooding can be caused by several different factors, ranging from user error to environmental conditions. Common causes of chainsaw flooding include:

  • Using an incorrect fuel mixture ratio can cause the engine to flood and prevent it from starting.
  • A dirty or clogged air filter can prevent the engine from getting enough air, and cause it to flood.
  • Using too much bar and chain oil in the fuel mixture can cause excessive smoke and make it difficult for the engine to start.
  • Gasoline that has been sitting for several weeks or months may become stale and cause the engine to flood.
  • Water can get into gasoline through condensation or if you mistakenly fill up at a water station instead of a gas station. This can cause the chainsaw to flood.
  • The wrong starting technique, such as pulling the starter cord too quickly or without allowing the engine to prime, can cause it to flood.
 Cause Excessive Smoke

Understanding these possible causes and taking steps to avoid them can help you prevent your chainsaw from flooding in the future.

How Do You Properly Clean and Inspect the Air Filter on Your Chainsaw to Prevent Flooding?

A key part of maintaining your chainsaw is regularly cleaning and inspecting the air filter. This helps ensure that the right amount of air flows into the carburetor, which keeps it running smoothly and prevents it from flooding. To clean and inspect your chainsaw’s air filter:

  • Remove the air filter cover from the chainsaw by loosening the screws that hold it in place.
  • Take out the air filter and inspect it for signs of dirt, dust, or other debris that may be blocking the airflow.
  • If you notice any build-up on the air filter, gently tap it against a hard surface to dislodge any particles.
  • Use a soft brush to remove any remaining dirt and debris from the air filter, then set it aside for a moment.
  • Spray compressed air into the air filter cover to blow out any dust or other particles that may have accumulated inside.
  • Reinstall the clean and inspected air filter back into the air filter cover and secure it with the screws.

By regularly cleaning and inspecting your chainsaw’s air filter, you can help prevent flooding and keep it running smoothly.

How Often Should You Replace the Spark Plug in a Chainsaw to Avoid Flooding?

The spark plug in a chainsaw should be replaced every one to five years, depending on the condition of the spark plug. If it appears worn or corroded, replace it sooner rather than later. A dirty or faulty spark plug can lead to a flooded engine and hinder the starting process.

Checking the spark plug regularly is important to ensure it is in good condition. To do this, remove the spark plug and inspect its cap for signs of dirt or corrosion. If present, clean the spark plug with a wire brush, then test it using an ohm meter. If the resistance level is in line with manufacturer specifications, the spark plug is still good to go.

Using an Ohm Meter

If the spark plug is beyond repair, replace it with a new one. The size and type of the spark plug should match what was originally installed on the chainsaw. If unsure, consult the manual for specific details or take the old spark plug to an auto parts store for help matching sizes and types.

How Can You Prevent Your Chainsaw From Over-revving and Causing Flooding?

To avoid flooding, you must follow a few simple steps to ensure that your chainsaw is running in optimal condition. Before starting the chainsaw, check for any loose fuel lines or air filter clogs.

Make sure all connections are tight and secure. Also, properly prime and choke the engine before starting it. Start the engine slowly and gradually increase the power until it reaches its maximum speed. If you feel like your chainsaw is running too fast, reduce the throttle slightly to prevent over-revving.

In addition to following these steps before starting up your chainsaw, always follow the manufacturer’s proper use and maintenance guidelines. Make sure that you are always changing the air filter regularly and that you are checking for any clogs or obstructions in the engine. If your chainsaw does become flooded, follow these steps to help get it running again:

  • Carefully remove the fuel tank cap and let excess fuel drain out.
  • Pull the starter cord several times to clear any fuel from the engine.
  • Wait a few minutes to let the fuel evaporate before starting the chainsaw again.

Following these steps can help prevent your chainsaw from becoming flooded and keep it running properly for years to come. Taking care of your chainsaw is essential to ensure that it runs efficiently and safely.


One of the main disadvantages of attempting to unflood a chainsaw is that it can be dangerous. If the saw is still running and you are trying to remove excess fuel from the carburetor, there is a risk of fire or explosions if any sparks come in contact with the fuel.

It Can Be Dangerous

In Conclusion,  unflooding a chainsaw is not as hard as it may seem. By following the steps outlined above, you should be able to successfully unflood your chainsaw and get it up and running in no time. Always take safety precautions when working with potentially dangerous equipment like a chainsaw. 

With a bit of patience and the right know-how, you can quickly unflood your chainsaw so that it’s ready to go whenever you need it. I hope reading this post has helped you learn how to unflood a chainsaw.  Make sure the safety precautions are carried out in the order listed.

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