How To Adjust The Chainsaw Carburetor?

A chainsaw is a technically demanding tool that needs to be serviced from time to time. Cleaning, replacing filters and, of course, adjusting the carburetor of the chainsaw will help to serve the entire period it has been laid. In this article, we will consider the issue of setting the carburetor. How and for what it is held.

Situations, in which adjustment is necessary.

New chainsaws are supplied from the manufacturer already with adjusted carburetors. It is called standard adjustment. But for the normal passage of the running-in process, it is required to lower the maximum engine speed and adjust the carburetor. After running in, the chainsaw needs fine-tuning to achieve maximum engine efficiency.
Also, a signal to conduct cleaning and adjustment is the increased fuel consumption, which adversely affects the work of the exhaust system. Put the chainsaw begins to smoke heavily and the silencer is clogged with soot, which in turn will lead to a decrease in power. With a lack of fuel in the mixture, the engine parts are poorly lubricated, and premature wear occurs. It is also not a quality mixture can cause engine seizure due to overheating (this is one of the reasons why the chainsaw does not start).
Adjustment is necessary in the case when the engine does not keep idle, stalls or does not develop full power.
Carburetor tuning should be done with clean air and fuel filters.


Proper adjustment of the carburetor chainsaw should be held using a special tool. a tachometer. It allows you to most accurately determine the maximum number of revolutions of the engine and adjust them according to the requirements of the manufacturer. To adjust, you must have a small slotted screwdriver. For some models of chainsaws, a special adjustment key will be needed, without which the work cannot be done.
The key for adjusting some models of carburetors is only available at service centers of chainsaws authorized for repair by the manufacturer. This measure is aimed at reducing breakdowns due to incorrect settings by inexperienced users and those who are engaged in repairs without having official permission to do so.
Setting up chainsaws, if possible, should be carried out in official service centers that have a certificate from the manufacturer.

How to adjust the carburetor

The setting algorithm of the chainsaw is quite simple and consists of the following steps:

  1. Engine adjustment for smooth operation at low revs.
  2. Set the carburetor to the correct flow of the fuel mixture at maximum speed.
  3. Exact adjustment of the carburetor for work in an idling mode.
  4. Check chainsaws in all modes.

Carburetor adjustment should be carried out after the engine has run a little and warms up.
Now we will consider how the correct adjustment of the carburetor of the chainsaw goes in more detail. Almost all models of carburetors have three adjustment screws. Screw (T) is responsible for fine-tuning in idle mode. Screw (H) setting work at maximum speed. Screw (L) controls the formation of a mixture at low revs. Twisting the screws (L) and (H) the fuel supply and the mixture is depleted, respectively, the revolutions increase.

Process description.

If the carburetor of the chainsaw is not adjusted, and it is not possible to start the chainsaw, the adjustment starts with the installation of screws (L) and (H) in the position of the standard setting. It is 1/5 of a turn of the screws until full tightening. After that, you need to start the engine, give a little work and heat up. The next stage is setting the low-speed mode. Optimum engine operation on the “bottoms” can be achieved by adjusting the screw (L) and idling (T). To do this, first screw (L) is twisted to obtain maximum engine speed, then released by 1/4, and screw (T) return to idle speed.
After setting up the work on the “bottoms”, the thrust and the maximum engine speed are adjusted. To do this, slowly tighten the screw (H) and check the revolutions according to the readings of the electronic tachometer.
To allow exceeding the maximum, engine speed declared by the manufacturer is unacceptable.
An important step is to check the saw in all modes of operation after it is adjusted, to do this, let the chainsaw cool down, and then start up using the cool tool start algorithm. If the saw starts up typically and runs idling smoothly, you need to check how it is sawing. If the verification process reveals deficiencies in the power of the chainsaw, then it is necessary to repeat the adjustment of the screw (H) by unscrewing it and checking the cravings in operation.
Loss of thrust at the maximum revs recommended by the manufacturer is an indicator of wear of the CPG or poor fuel quality.

Adjusting the Chinese chainsaw carburator.

Carburetors mounted on Chinese-made saws are made similar to European ones and have the same setting screws.
The adjustment of the carburetor of a Chinese chainsaw is based on the algorithm presented above and is distinguished by the fact that during the initial tuning of the screws (L) and (H) they must be turned in two turns. Further, the carburetors of the Chinese saw are regulated in the same way as the European ones.