How to Start a Flooded Chainsaw

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Are you a chainsaw and your chainsaw has got flooded and isn’t starting? Do you want to find the answer to how to start a flooded chainsaw? If yes, then you are definitely in the right place.

Starting a flooded chainsaw involves putting your chainsaw on a flat, clean surface, removing the top cover, checking the spark plug and its cap, pulling the cap gently while ensuring the wiring doesn’t break, untightening the spark plug, and drying out the wet electrode for removing any excess fuel. The tip of the spark plug will have a little fuel, so dip the tip in gas and light it with fire.

Then, you should remove excess fuel from the combustion chamber before keeping your foot on the chainsaw and pulling the starter rope. Put the cylinder down position and then plug the spark plug into the hole. After that, take a wrench and tighten the spark plug. Lastly, put the top cover and reinstall it before starting the chainsaw.

In this article, you will get to know the reasons why a chainsaw floods, how to start a flooded chainsaw, different methods to unflood a chainsaw, and more. Continue reading to get all the answers that you are looking for.

Struggling With the Chainsaw Flooding?

Experiencing the issue of a flooded chainsaw is quite common, even if you are just an occasional or frequent chainsaw user. This is why it is important to learn about flooding in a chainsaw and how to start a flooded chainsaw. When the fuel overloads and ends up filling the combustion chamber beyond its capacity, it will struggle to start. It is referred to as a flooded chainsaw. The combustion chamber in the chainsaw is responsible for igniting the spark.  However, if the fuel becomes excessive in the combustion chamber, it leaves no place for oxygen in it.

Therefore, your chainsaw will fail to start and end up becoming flooded. A great way to prevent this issue from occurring would be to clean the combustion chamber regularly.

If the problem occurs, can a flooded chainsaw fix itself? The simple answer is no. This is why you’ll need to learn the right method to start a flooded chainsaw.

professional logger holding a flooded chainsaw

If you want to learn to start a flooded chainsaw, then you shouldn’t worry, as you aren’t alone. There are many people in this situation. In fact, not just chainsaw users but many people who use dirt bikes, weed whips, older vehicles, or any piece of equipment with a carburetor would have experienced a flooded engine.

Flooding an engine is a common thing. But the good news is that it is also very easy to fix. For starters, you must find out how the engine good flooded and then think of a way to get your saw up and running again. Here, you will get to know how to start a flooded chainsaw.

How to Start a Flooded Chainsaw

You don’t have to worry at all if you are encountering the problem of a flooded chainsaw. It will only take 5–10 minutes if you want to start a flooded gas-powered chainsaw. To check, you will have to pull the starter rope to start the chainsaw. If it fails to start, you must check the spark plug and then clean/replace the air filter. A gas-powered chainsaw that doesn’t start after all this is probably flooded. To solve this issue, you need to follow the steps mentioned here –

Step 1: Remove the top cover

First, you need to put your gas-powered chainsaw on a flat, clean surface. It will help you ensure that your chainsaw remains clean and doesn’t slip away while you’re fixing it. After that, you have to look for the top cover and remove it. You will find that your chainsaw has a control lever for adjusting the position of the top cover. You have to move it lower for removing the cover.

The position of the lever might vary with different models and different brands. So, remember to always go through the owner’s manual to read the instructions thoroughly.

Step 2: Check the spark plug and its cap

Once you have removed the top cover, you need to check for the spark plug and its cap. The engine in your chainsaw will have a spark plug, and it will be responsible for ignition. Use the owner’s manual for locating the exact position of the chainsaw spark plug. Remember, the position will be different for different types of chainsaws of different brands, including gas-powered chainsaws, electric chainsaws, mini chainsaws, battery-powered chainsaws, and milling tools.

You will find a spark plug cap on the spark plug. There will be a high-voltage cap associated with the spark plug. You must pull the cap gently such that the wiring doesn’t break, as pulling off the wire along the cap would be problematic.

Step 3: Untighten the spark plug

There is a special type of wrench called “scrench”, which is a combination of screwdriver and wrench, and it comes with a chainsaw. You will need to untighten the spark plug carefully with the help of a scrench. The spark plug will be pretty tight, and you need to apply a steady force in rotating the wrench anti-clockwise.

This will untighten the spark plug, and you must unscrew the rest of it with your hand. Once you have removed the spark plug, you must locate the choke control lever and press it. This deactivates the chainsaw choke. Make use of the owner’s manual to know how to start a flooded chainsaw.

Step 4: Remove the excess fuel

After unscrewing the spark plug, you need to dry the wet electrode for removing the excess fuel. The next step would be to pull the starter cord and fully depress the lever.

The top of the spark plug will also have a little fuel on it. You need to dry the tip in gas and light it with a fire. There are multiple ways of drying the tip, including using a paper towel or using an air compressor to blow.

You must avoid the fire method such that the electrode doesn’t end up catching fire. There might be micro-cracks in the ceramic insulation present on the electrode.

Step 5: Remove any excess fuel from the combustion chamber

The next step would be to remove any excess fuel from the combustion chamber. Move the chainsaw to the off position of the lever to the “Off” position. This will make sure that vapors do not end up catching the spark.

Now, you need to keep your foot on the chainsaw and start pulling the starter rope. Pull the starter rope 4–5 times. It will make space for oxygen to enter the combustion chamber.

Step 6: Tighten the spark plug and reinstall the top cover

Now, you need to put the chainsaw cylinder in the down position and then plug the spark plug into the hole. Use a napkin while you are doing this to absorb any excess fuel. Take a wrench and begin tightening the spark plug. After that, you must put the top cover back in its position and then reinstall it.

Step 7: Start the chainsaw

Now, start your chainsaw by pulling the starter rope. Keep the choke lever in a full-open position, and then slide it back to half-open. When your chainsaw finally starts, you must move the chain lever to the “Off” position.

How to fix a flooded STIHL Chainsaw Engine

Signs of a Flooded Chainsaw

A flooded chainsaw can be caused by having too much fuel inside the chainsaw engine, which doesn’t allow the fuel to ignite. You should think of it like this, combustion inside the engine needs air and fuel. By having too much fuel, there won’t be enough room for proper air mixture when the spark plug is trying to ignite the gas.

As the spark plug isn’t able to ignite the gas without air, you will be left pulling the starter cord on the chainsaw repeatedly without it ever starting.

Early signs of a flooded chainsaw include the smell of gas coming from the muffler. The pungent gasoline smell and trouble in starting would be a clear sign that your chainsaw is flooded, and you must learn to start a flooded chainsaw.

How Does a Chainsaw Get Flooded in the First Place

If you have a flooded chainsaw, chances are that you flooded it by over-choking it. It can happen by using the choke despite not having the chainsaw in the run position, or by using the choke on a warmed-up engine when it isn’t really required.

Some chainsaws automatically switch to the run position once you pull out the choke lever. This is a neat feature to have as it’ll help eliminate user error, but not every chainsaw or small engine comes equipped this way.

Moreover, if you have been using a chainsaw for a long time and then shut it off, you won’t have to choke it to start back up as the engine will still be warm. This can cause the engine to flood.

Different Ways to Unflood a Chainsaw

If you have a flooded chainsaw, you’ll have multiple options that work quite well and will get your chainsaw running again without a lot of effort. Here are three easy methods to unflood a chainsaw so that it can be started easily –

1. Let the fuel evaporate

The first option is also the easiest, as it doesn’t require a lot of effort on your part. In fact, it simply takes time. Many people wonder if a flooded chainsaw is capable of fixing itself. The simple answer is not always.

By letting your chainsaw sit for around 20 minutes, it’ll allow some of the fuel inside the engine to evaporate. This method will have mixed results, as the outside air temperature will play a role in how quickly or slowly the fuel evaporates.

On a severely flooded engine, you might allow it to sit for multiple days, and it will still not start the engine. So remember, even though this method might come across as the easiest, it won’t always work.

Just remember, when you are attempting to start the engine after it has been left for 20 minutes, you must ensure that the choke is not on. You will want to pull the rope with the choke off multiple times, which will cause the chainsaw to start.

2. Unflood the engine with no tools

The next option to unflood a flooded chainsaw is not only easy, but it is also very effective. The first step would be to engage the chain brake and then place the chainsaw on the ground.

With the choke in the (off / no choke position), you need to kneel down and then place your knee over the powerhead of the chainsaw. This will keep the chainsaw firmly on the ground while keeping your hands free.

Using one hand, you should fully depress the throttle lever while you’re pulling the starter role 10–20 times with the other hand. Typically, you should take your right knee and then place it on the chainsaw. Using your left hand to hold down the throttle, you should use your right hand for pulling the starter rope.

Although this can be slightly exhausting, by the time you have pulled the starter rope 10–20 times, your chainsaw will start. This method will create a lean mixture of fuel as there will be full throttle with no choke.

Aside from chainsaws, this is also a popular way of starting older vehicles, where you will have to press the gas pedal all the way to the floor and crank the engine numerous times until it starts.

3. Removing the spark plug

The third way of unflooding a flooded chainsaw will involve removing the spark plug. Start off by ensuring that your chainsaw is in the “Off” position. Next, you must remove the rubber foot from the spark plug and then remove the spark plug using a scrench.

Do not install the rubber boot to the spark plug as the plug might ignite the gas inside the chainsaw. You should place the spark plug away from the chainsaw and then turn it upside down.

While you’re holding the chainsaw upside down, you must take your free hand and then slowly pull the starter rope of your chainsaw. As you are pulling the starter rope, the chainsaw will start pushing gas out of the cylinder.

Do this 4–5 times, or until all the gas has been removed. After that, take a dry cloth and then wipe off any gas that is on the spark plug. As the engine was flooded, you will notice excess gas on the end of the spark plug, which must be removed before it is installed.

Finally, you need to reinstall the spark plug and boot before placing the choke in the “Off” position with the chainsaw on run, and starting the chainsaw.


What causes my chainsaw to flood?

There can be numerous reasons why you might be having a flooded chainsaw. Some of the primary reasons that could cause flooding of a chainsaw are incorrect mixing of fuel, a spark plug wet with fuel, or improper carburation among others.

How much till will a flooded chainsaw require to start?

There is no rocket science involved in starting a flooded chainsaw. As long as you are following all the guidelines carefully, it will not take you longer than 5–10 minutes to start a flooded chainsaw.

Can I start a chainsaw with a drill?

If you are a DIY-er, then this method might work for you. However, it is effective only for a normal home-use chainsaw. The drill won’t work for a flooded chainsaw. A flooded chainsaw will require other steps to be followed. The use of a drill might start your chainsaw, but it will eventually stop again.

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Hi, I'm Mike - but my friends call me Backyard Mike. I'm the founder of this website, and I'm addicted to outdoor power tools. I love to work with wood and share my knowledge here on this website with you. You can find more about me here.