How to Adjust Carburetor on Bolens BL 110 trimmer

Your Bolens BL 110 Trimmer turns on, but crackles and bogs out? Well, worry not, and just follow the steps below. Within a few minutes, your trimmer will be running like it is brand new again!

Why/When do you need to adjust the carburetor?

Your Bolens BL 110 trimmer will not function properly if the high or idle screw of its carburetor is not set correctly.

Therefore, you need to adjust your carburetor to make sure that both screws are tuned correctly. This usually happens when the tuning set in the factory is not accurate.

What do the High and Idle Screws do?

These screws are used to adjust the flow of gas, to obtain the perfect composition of fuel required for running the trimmer.

The idle screw controls the flow when the trimmer is in idle condition i.e. when the trigger is released.

The high screw controls the flow when the trimmer is running at maximum speed, i.e. when the trigger is pushed to obtain full throttle.

Tools Needed for Adjustment

  • Pacman screwdriver                                                              


Figuring out the Problem

If your trimmer turns on but the throttle drops when you push the trigger, then the problem is with the high screw.

If it works fine on pushing the trigger but bogs out when you release it, then you need to adjust the idle screw first, and then adjust the high.


Step 01: Locate the high and idle screws

As shown in the picture, there are two circular screws.

The top screw is idle and the bottom screw is high.

Step 02: Placing the screwdriver

Now, you can use two different screwdrivers for this step.

  • The Pacman Screwdriver

The Pacman screwdriver will fit perfectly in this type of screw.

  • The Flathead Screwdriver

If you do not have a Pacman screwdriver, then you can use a flathead screwdriver instead.

To be able to place a flathead screwdriver, first, you will need to use a Dremel tool and adjust its cutting blade on it.

Next, use it to grind the top of the screw so you have a place to fit the flathead screwdriver in there, as shown in the image.

Now you can easily use the flathead screwdriver to adjust the screw.

Step 03: Adjusting the idle

Note: Skip this step if your trimmer is working fine when you leave the trigger.

Insert your screwdriver in the top screw

  1. Rotate about 45 degrees (half a turn) counterclockwise.
  2. Now turn on your trimmer and check the throttle on releasing the trigger.
  3. If you observe an improvement, but the problem continues, then slowly rotate a few more degrees counterclockwise and keep observing the throttle when you let go of the trigger.
  4. It might take a while but you will find the point where it will stop bogging down.

Remove the screwdriver. Your idle is now tuned.

In case you see no improvement after the initial 45-degree turn, or if the trimmer turns off even faster, then –

  1. Rotate the screw back to its original position and then rotate 45 degrees clockwise.
  2. Repeat the same steps until you have tuned the screw.

Step 04: Adjusting the high

Now, you have to adjust the high so that you are able to achieve maximum throttle when you push the trigger.

  1. Insert your screwdriver in the bottom screw, and rotate about 45 degrees counterclockwise.
  2. Now turn on your trimmer and check whether the throttle goes up on pressing the trigger or if the trimmer bog out.
  3. Keep rotating the screw slowly and checking the throttle at the same time.
  4. If your throttle begins to slow down, rotate it back in the opposite direction until you find the point where the throttle is maximum.
  5. This is the point you need to tune your trimmer to.

If the problem does not get solved by counter-clockwise rotation, then take the screw back to its original position and repeat the same steps, but in the clockwise direction.

Basically, you have to figure out whether the carburetor of your trimmer needs to be tuned clockwise or counterclockwise.

Congratulations! You have adjusted the carburetor on your Bolens BL 110 trimmer. You can now test out your trimmer and it should be working perfectly fine!

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