Fixing a Broken Chainsaw Carburetor

Date Posted: 10 October 2022 


The carburetor is an important component in small engines such as chainsaws since it impacts the machine’s performance. A neglected chainsaw carburetor causes a slew of issues. This post will go over how a chainsaw carburetor works as well as how to keep the carburetor in good operating order.

How Does a Chainsaw Carburetor Work?

The carburetor on a chainsaw is simple but not without complications. The carburetor’s duty is to precisely meter extremely small amounts of gasoline and mix it with the air entering the engine so that the engine operates correctly.

If there is insufficient gasoline combined with the air, the engine may fail to start or get damaged. If there is too much gasoline in the air, the engine will either not operate, run with a lot of smoke, run badly, or waste fuel. In short, the carb is in charge of fine-tuning the mixture.

Symptoms of a Bad Carburetor

The Chainsaw Is Performing Below Its Capacity. When a carburetor is dirty or needs fixing, it fails to supply a proper charge to the combustion chamber, resulting in lower efficiency and power.

The Chainsaw Keeps on Overheating or Backfiring. Overheating or backfiring may occur when a lean mixture is delivered to the combustion chamber by the carburetor. A lean mixture contains either more than the needed quantity of air or less than the required amount of fuel.

The Chainsaw Produces Black Smoke All The Time. Black smoke is another classic indicator of a failed carburetor. When the engine begins to blow black smoke, it shows that the carburetor is providing more gasoline than is necessary, resulting in excessive fuel use.

It’s More Difficult to Start the Chainsaw Than Ever. An engine with a filthy carburetor is difficult to start because the necessary quantity of energy is not created in the combustion chamber.

Don’t ignore any of these signs the moment you observe them in your chainsaw. A failing carburetor will directly affect not just your chainsaw’s fuel efficiency but also its overall performance. 

Cleaning The Carburetor

Once you notice your chainsaw showing any of the four signs of a failing carburetor, it’s possible that it may only need some cleaning. This is especially true if you haven’t cleaned your chainsaw’s carburetor in a long time. 

Chainsaw carburetor cleaning isn’t complicated. The best way to clean it is to take it out and open it. However, if you clean your chainsaw’s carburetor regularly, there’s a lower chance of it accumulating gum and dirt. If that’s the case, you can clean it without taking it apart. You will only need a carburetor cleaning liquid to get the job done.

You can do this by placing at least 4 ounces of carburetor cleaning liquid into the fuel tank. After this, start the chainsaw and let it idle or allow it to run at low RPMs for a few minutes. This will allow the cleaner to enter the fuel systems and wash away any sticky residue that might be clogging the components. Alternatively, you can spray some B12 into the pilot air jet to clean the carburetor thoroughly. 

To test your chainsaw through its paces, run it at full throttle. If it starts with no problem at all and continues to work at high speed with no signs of speed or power loss, it means you have cleaned the carburetor thoroughly.

Fixing a Broken Chainsaw Carburetor

If cleaning the carburetor doesn’t improve the chainsaw’s performance, it only indicates that the carburetor needs some replacing. Before performing any of the steps, be sure to wear the necessary gear and to have the right tools, such as a chainsaw carburetor adjustment tool. When you’re ready, follow the steps below:

Remove the Carburetor

The first step is straightforward: remove the carburetor. To begin, remove the top cover from your chainsaw near the handle. The carburetor would be positioned beneath the air filter. Loosen the screws on the air filter and remove it completely. Next, you will need to  clamp the gasoline lines so that no petrol seeps out when they are removed. Remove the gasoline lines and unscrew the carburetor afterwards, and then remove the carburetor and check it.

Remove the Diaphragm

Unscrew the carburetor from its place. If you see that the diaphragm is also damaged, it’s better to remove it as well. After unscrewing the carburetor, you will be able to see the fuel jets.

Use Cleaner Liquid

Now that the carburetor has been removed, the next step is to spray it clean with a cleaner liquid. Any local hardware store should have a spray cleaner available that’s powerful enough to penetrate and loosen heavy deposits. Spray the interior and the jets to get rid of debris that might be clogging the jets.

Replace Any Broken Part

Once you’re done cleaning the carburetor, identify components that are possibly worn out or broken. This includes the springs or the diaphragm. If you see any parts that need to be replaced, take them out immediately and replace them. Ideally, you’d want to invest in a quality carburetor repair kit

The most basic kits include air horn gaskets, fuel inlet seat, accelerator pump, flange gasket, throttle body gasket, choke gasket, and check balls. Depending on the kit, it may contain additional components.

Get Your Chainsaw Carburetor Only at Jono & Johno

Chainsaw carburetor adjustment or repair isn’t very difficult if you know how to proceed. In most cases, simple cleaning should get the engine running in no time. In some cases, however, the carburetor itself may need to be replaced. When the time comes when chainsaw carburetor replacement is the only option for you, be sure to get your carburetor repair kit and parts only at Jono & Johno.