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My Chainsaw Will Only Run on Choke: How to Fix This

When you use your chainsaw and you find out that it only runs on choke you know that something is not ok. During a cold start you need to use your choke to make it run, but after it runs for a short while the choke should be turned off. If your machine starts slowly or does not operate smoothly, having a professional check and fix it would help.But some of the problems can also be solved yourself.

My Chainsaw Will Only Run on Choke: How to Fix This

When your chainsaw only runs if the choke is on the problem, in most cases, is a result of fuel supply problems or a faulty carburetor. To fix the problem you should check and clean the fuel system and carburator.

This blog post will show you the steps to fix the choke issue.

Step by Step Procedure to Follow When the Chainsaw Runs on Choke Only

● Step 1: Check the fuel/oil mixture

If the mixture of oil and fuel has the impurities, chances of your chainsaw only running when the choke is on are high. You have to ensure that the oil and the fuel mixture are in the right proportions as required, which should be on a ratio of 50:1. However, if it becomes hard for you to get the proportions right, find an expert who can assist.

● Step 2: Clean the fuel filter

In other instances, the problem is because your fuel filters are faulty or dirty. You need to take them out and check if they have particles trapped in them. The cleaning procedure involves using kerosene or petrol and then letting the filters dry before reinstalling them and trying your chainsaw once more.  Check if your chainsaw runs without the choke on, and if it is still not working, you should look at the fuel hose. 

● Step 3: Check the fuel line

With a bad or broken fuel hose, there will be an inadequate supply of fuel into your chainsaw’s engine, which is why it might run on choke. Check your fuel line to confirm that it is clean and working as needed. In case it is not functioning as required, get a new fuel hose, and start your chainsaw again. If the problem is still there, move to this next step.

● Step 4: Use the correct gas type

Trying different gas could help in fixing the problem. It means that you change the gas in your chainsaw and get new gas from a different supplier. Maybe your current supplier does not have clean gas, and that could be making your chainsaw run on choke. Once you have removed the gas from the tank, clean it and wait for it to dry before putting new gas. If, after adding the new gas, your chainsaw does not work without the choke, other issues could affect the machine.

● Step 5: Check the crankcase

Crankcase can have unnoticed breakage or another underlying issue that could cause the air to leak, which causes problems to the machine. Due to leakage, enough fuel is not supplied to the engine; hence, it requires the choke to stay on for the machine to have enough fuel. Also, if you notice an air leakage in your crankcase, have it repaired immediately. Restart your chainsaw and see what happens

● Step 6: Check the fuel speed control valve

See that you take a look at the fuel speed control valve as it could be the reason your machine is running only with the choke on. Adjust the valve manually to see if there are any changes. Your valve will only run on high speed if there is prolonged running time of your engine but, if you turn it correctly, the issue will be fixed.

● Step 7: The carburetor gasket

Between the carburetor and the motor of your chainsaw, there is a gasket. Check if the gasket is worn out and replace it with another one. Gaskets are locally available the only issue is, sometimes you might get one that is thinner than the original one, in this case, you use two for them to fit in well

● Step 8: Remove and clean all fuel related parts

Having checked all the above parts and confirmed that they are working correctly, remove all fuel-related parts: the carburetor, air-fuel, fuel filter, fuel hose. Ensure that you clean them one by one and check if there is any breakage or crack issues and repair them, if the problem is still there, you have to rebuild the carburetor

● Step 9: Check the low idle carburetor setting

It is common to get chainsaws with low idle carburetors set by the companies that manufactured them; the low idle carburetor helps reduce fuel consumption. To rectify this problem, you need to check the settings in the low idle carburetors and adjust to fit the amount of fuel required by your chainsaw.


  • Ensure that your fuel and oil mixture is correct.
  • Be sure to have a clean air and fuel filter for your fuel.
  • Look at the fuel hose to ensure it is in excellent condition.
  • Ensure you use clean gas
  • See to it that your crankcase is not broken.
  • You have to ensure that your speed valve is adjusted as needed.
  • Check the gasket between the motor and the carburetor, and if it is not looking great, rebuild it.
  • Check the engine to make sure that nothing is melting in it.

Why Is It Bad to Leave Your Chainsaw Running on Choke?

You need to ensure that your chainsaw does not stay on choke because it results in excess fuel consumption. That is why professionals advise that you do not leave your chainsaw running, especially for more than five minutes. These are the three common problems that can cause such problems:

● Air leakage in your chainsaw:

If there is excess air getting into the carburetor or the fuel tank, it will be hard to keep your chainsaw running. That is because there is a lot of air getting into the combustion chamber hence causing the machine to overwork. To correct the problem:

  • You have to inspect your carburetor to see if it is properly fit and that the gasket seal is intact.
  • Look at the fuel line to see if there is a loose connection or any visible cracks.
  • If your engine has a fuel primer, check it out for leaks and cracks that should be fixed to stop air leakage.

● Contamination of the fuel:

If the fuel is contaminated, it could be a result of fuel and air mixture, leading to a clogged carburetor.

  • Have the carburetor’s internal parts cleaned by a professional, or if the damage is extensive, replace the carburetor.
  • Drain the fuel tank and add fresh and clean fuel.

● Alcohol Content:

If the fuel has excess alcohol, you have to replace your fuel with less alcohol content if that is the case.

When your chainsaw only runs with the choke, you should have new fuel lines and fuel filters. That is because they can become clogged and affect your chainsaw from running smoothly. Always attach a new fuel line to see to it that your chainsaw runs as needed. If there is nothing you can do, seek help from a professional. Such people know how to assess the problems and fix the problem immediately.

FAQs about Chainsaw Running on Choke

● Why Does the Engine Run on Choke?

If you realize that your chainsaw runs only when the chainsaw is on and stops working when it is turned off, there is an issue with the carburetor. The carburetor is responsible for mixing air and fuel before it gets to the engine. That means you need to fix it if you want your chainsaw to run as required.

● Is It Bad for A Chainsaw to Run on Choke?

The short answer is yes. The more air that gets into the system, the harder it gets hard to keep running your chainsaw running at all times.


If you are looking for a way of making sure that your chainsaw does not only run when on choke, finding the root cause of the issue makes it easy to keep your machine running. You can solve the problems through the steps discussed above. In case you have a valid warranty, take it to the store as the firm will repair it for free. Hopefully, through this article, you will find a way of fixing your chainsaw if it only runs with the choke on, and that you will not have to look for a professional. That way, you will save money and time and get a chance to finish your tasks on time.