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Chainsaw Throttle Not Working? 3 Causes and Fixes

Chainsaw Throttle Not Working? 3 Causes and Fixes

If you’ve been using chainsaws for a while, you know how vital throttle is. Without the right amount of control over it, you risk hurting yourself and others while using your chainsaw. Depending on where the problem lies, there are several things you can do to mitigate the effects of a defective chainsaw throttle. 

When a chainsaw throttle isn’t working, it might be because it’s dirty, the gas has gone bad, the air filter is clogged, or parts are improperly aligned. Fixes include cleaning the saw (including all nooks and crannies), replacing old gas with freshly mixed gas, and replacing worn parts. 

A broken or malfunctioning throttle is one of the more common problems for chainsaws. But don’t worry: I have a list of potential causes and fixes so you can get your saw back up and running in no time!

1. Carburetor or Fuel Mixture Issues

The most common reason for an idle chainsaw engine is that the fuel or carburetor mixture needs adjusting. The carburetor is the device that mixes fuel with air. When you first turn on the engine, the carburetor is the first part to receive fuel. If the carburetor is clogged or doesn’t have the right fuel mixture, it cannot draw in enough power.

Also, the carburetor may have too much air, causing the engine to run too lean. This is likely caused by accumulated dirt in the carburetor during storage. 

How To Fix 

Most of the time, you can fix carburetor issues on your own. Here are some of the things you can do:

  • Clean out all of the excess dirt, and check to make sure there isn’t any debris in the air filter or air intake port.
  • Make sure all the screws on top of the carburetor are secured tightly and gaped according to specifications.
  • Make sure the gas you’re using is freshly mixed and in the correct ratio for your saw. Too much gas causes plugs to misfire and damage the throttle.

Check out this easy-to-follow Youtube video that shows you how to change the carburetor on standard chainsaw models such as Husqvarna, Jonsered, RedMax, and Zama:

Husqvarna Chainsaw Carburetor Replacement (Same for Jonsered, RedMax, and Zama)- Ranch Hand Tips

If none of these fixes works for you, replacing the carburetor will be your best bet. Fitting them is usually a simple job, and the parts are easy to find as most chainsaws use a Walbro or Zama carburetor. 

2. Chainsaw Bogs Down

If your chainsaw bogs down, it might be because your blade isn’t sharp enough. A blade that’s too dull will slow down as it makes contact with what you’re cutting, causing the engine to rev faster as it tries to move the blade forward.

Bending or misaligning of the blade is also a potential cause of this issue. That’s because it cannot cut properly and will slow down the engine as it pushes what you’re cutting through the saw. 

If you’re cutting wood and it’s too thick or moist, your chainsaw can also bog down. The wood may also have a high percentage of knots, making it more difficult to cut. 

Another common cause of this issue is low oil pressure. To fix this problem, you need to replace the oil filter and/or clean out the oil filter screen. 

Finally, there can be something wrong with your spark plug or ignition system. Either of these can cause engine issues. 

How To Fix

The most common cause of bogging in chainsaws is poor maintenance. Always take care of your chainsaw and inspect it for wear and tear to identify potential problems before they become serious enough to damage the engine or cause it to stall completely. 

To prevent bogging issues with your chainsaw, follow these tips:

  • Sharpen the blades. When a chainsaw becomes dull, it wears out its motor and causes wear and tear on the rest of the machine. You can sharpen your chainsaw blade with a metal file at home, or you can take it to an engine repair shop
  • Use fresh gas. Try not to use gas that has been sitting in the tank for more than 30 days (source). Either replace the gas or use a stabilizer. Both are designed to keep fuel stable and fresh for months 
  • Lubricate your chain. Chainsaws can bog if not properly lubricated because of friction and heat generated by excessive revving. Keep your chainsaw lubricated to avoid stalling or overheating and ensure clean cuts.
  • Clean your chainsaw. Always clean your chainsaw before and after each operation to prevent malfunction. 

Looking for a fast and easy way to clean your chainsaw? Take a look at this Youtube video for tips on giving your saw a quick once-over:

The EASIEST Way To Clean A Chainsaw

3. Chainsaw Cuts Out 

Chainsaws have a built-in safety feature that cuts out the engine when it’s pushed beyond its limits. This is to prevent injury from overloading the chain. It’s common for this safety feature to go off when the chain begins to overheat. 

Your chainsaw cutting out can be caused by several factors, including not properly lubricating the chain, running it for too long, or running it upside down. If you’re experiencing chain overheating, it’s best to take a break and let the chain cool down before using your saw again.

How To Fix

Chainsaws that start but stop are generally caused by a lack of fuel and air in the engine. If the problem persists after you’ve left the saw alone for a while, try the following fixes:  

  • Drain and replace old gas.
  • Clean the carburetor.
  • Clean or adjust a dirty spark plug.
  • Clean out the fuel line.
  • Clean or replace the air filter.


A chainsaw can be one of the most valuable tools in a woodworker’s arsenal. However, like any tool, it must be treated with respect. You must check your chainsaw before every use to ensure that it’s properly maintained. 

Applying fixes to your saw can be a long and frustrating process, but when you find the solution to your problem, it’s pretty rewarding! When in doubt, consult your owner’s manual for help, or consult a professional (especially if your model is relatively new).

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