How to Adjust Chainsaw Carburetor Properly? [Learn to Tune Right]

Every type of saw needs to be adjusted periodically for it to run smoothly for a long time. The condition of the engine is determined by how much power it can endure under maximum power, minimal stroke, and rich smoke production.

And the adjustment of the carburetor depends on the fuel and air pressure used, given the amount of power during heavy use.

Knowledge of proper maintenance is crucial when owning such a high functioning tool, as it becomes out of tune while you’re using it. Follow this article to learn how to manage your chainsaw just by adjusting the carburetor for any wood cutting services by yourself.

How to Clean a Chainsaw Chain, Carburetor, and Air Filter

Reasons to Adjust Your Carburetor

If you don’t monitor the air and fuel needs of your chainsaw, the excessive smoke build-up can cause longtime damage to the saw’s engine. A user can make several adjustments without realizing it, and usually, it becomes off-tune in the process.

Factors such as the saw being operated in different elevations, air pressure, and a plethora of other functions don’t let the adjustments be constant throughout its life.

Related: How a chainsaw works.

The Three Carburetor Adjustment Slots

There are three adjustment screws on the side of the chainsaw that determines the speed, power, and air-to-fuel ratio.

  1. Idle Speed

This adjustment determines the availability of the throttle valve when the trigger is released. When the adjustment is too low in the setting, the engine might die, and the high setting can engage the clutch, and the chain might accidentally run.

  1. Low-Speed Fuel Adjustment

At idle speed, this adjustment determines the ratio of the fuel in the air and fuel mixture in the carburetor. When the mixture is too rich, the engine might die at idle speed, and a lean mixture can be too much for the engine to take, which might lead to surging.

  1. High-Speed Fuel Adjustment

At a cutting speed, this adjustment determines the fuel in air and fuel mixture in the engine.

Tools You’ll Need to Buy

  • Flathead screwdriver
  • Toothbrush
  • Compressed air
  • Tachometer


  • Always check the idle screw before you start. The chainsaw can accidentally turn on, even in idle mode.
  • Clean out the air filter before making adjustments, a dirty air filter can often overheat the engine.
  • Make sure the bar and chain are adjusted to the desired tension.
  • Test out the adjustments in a well-ventilated area, on a clean surface.

Suggested reading: Chainsaw Mills Reviews.

How to Adjust Chainsaw Carburetor?

We’ll walk you through the step-by-step process here.

  • Step 1: Clean out the Screws and Filter

Clean the adjustment screw holes gently, using either a Phillips screwdriver or an air compressor. Then, clean out the saw’s air filter, a clogged air filter can make the adjustment too lean and cause major damage down the line. Similarly, make sure the fuel level is more than half full to avoid the risk of making rich adjustments.

  • Step 2: Set It at Idle

Set the speed to 2700 RPM, while it’s in the idle setting. Make sure it is not set to idle while the chain is running and set the speed using a tachometer.

Rev up the engine and let the carburetor warm-up, as a cold engine can become too rich. Move on to the next step, only if the saw will not idle.

  • Step 3: Set It at Low

Insert the screwdriver into the low-speed adjustment slot. Turn the screwdriver until the engine starts to surge, or it becomes leaner. Remember the angle of the screw and turn it out slowly.

Turning the screw out makes the adjustment rich; remember this angle as well. Find the midpoint of both angles to generate the idle position or your desired adjustment.

  • Step 4: Set It at High

Reset the idle speed, as the fuel adjustment can change the setting. Insert the screwdriver into the high-speed adjustment slot. Check the RPM with your tachometer, while the trigger is kept open. Generally, the maximum RPM for most chainsaws stands between 11,500 – 13,500 RPM.

Find the desired RPM for the specific model of your chainsaw, and use your tachometer to tune it. It’s best to not set maximum RPM without a tachometer, as it can cause damage to the engine.

  • Step 5: Fine-Tune All Three

Once you’re done with the previous step, fine-tune the idle and low speed again. The adjustment of one slot can change or reset the other speeds. Go back to idle speed after you’re done with all the steps, and your chainsaw should be adjusted and ready to use!

Also Read: The History Of The Chainsaw.

Keep Your Chainsaw Carburetor Fine-Tuned for Any Project!

Carburetor adjustment can change anytime, and although you can work with an unadjusted engine, this negligence can cause irreparable damage to your chainsaw blades and functionality.

Follow this guideline to equip yourself with the knowledge to readjust your chainsaw to combat any project or situation!

Also Read: How to Tighten Chainsaw Chains and How Tight It Should Be?

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