How to Adjust the Idle on a Chainsaw

how to adjust idle on a chainsaw

Gasoline saw is the most popular gardening equipment, which has long been very popular among gardeners and owners of private houses. Not a single event in the field of construction and repair work is also complete without it. Well, if we talk about the profession of a lumberjack, then we can confidently say that such a tool is an element of basic necessity, without which there is nothing to do in the forest.

However, like any sophisticated equipment, a chainsaw requires periodic maintenance. For example, in the case of excessive loads, there may be malfunctions with its work, which often entail unexpected and very unpleasant consequences.

In our case, we will talk about the device responsible for supplying the fuel mixture to the combustion chamber, namely, the chainsaw carburetor, the correct operation of which depends on how powerful and at the same time the equipment will be economical. Therefore, if you notice a clear error in the operation of your saw tool, the first thing that is recommended to be done is to adjust the carburetor.

When is adjustment necessary? ?

Inaccurate carburetor operation, which may be lost due to the shift of the adjusting screws.
Piston wear
Clogged carburetor (in this case, not only its adjustment is necessary, but also disassembly with subsequent cleaning).
Frequent temperature changes in combination with increased humidity in the room in which the tool is stored.
Incorrectly selected fuel mixture (try replacing the fuel, if the result does not follow, adjust the carburetor).
Increased vibration.
The engine does not start or stalls after start.
Fast fuel consumption and plentiful exhaust.

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Carburetor device

The structure of the carburetor in different chainsaws may vary, but the principle of its operation remains the same. A fast air stream moves in the direction of the air channel, the speed of which is regulated by a special valve that blocks the outlet. The fuel is fed into the channel by spraying and mixed with the incoming air stream, creating an air-fuel mixture. Then the resulting composition is fed into the engine.

Carb setting purpose. ensure the correct quality and quantity of combustible material entering the combustion chamber. In the event of an incorrect ratio, the proper operation of the engine becomes at risk.

Carburetor Dismantling

Since the carburetor device seems to be for all models, a new professional Grunhelm gasoline saw. However, it is worth noting that the problem on which the tool has ceased to function is necessary, to look gradually, from simple to more complex. Dismantling a mechanism, without revealing a reason, may turn against you. But if such a need nevertheless arose, for example, it required cleaning it from dust and dirt, then this should be done with utmost care.

Video: How to Adjust the Idle on a Chainsaw


Step-by-step instruction :

Carefully remove the top cover by turning the special plastic screw.
Inside we will see the component of the air filter, which also needs to be removed.
To gain full access to the carburetor, we take a screwdriver in our hands and unscrew the three screws located on the sides of the case.
Then remove the fuel pipe and the drive rod.
Carefully remove the cable end and disconnect the gas hose.
Having done all these manipulations. finally, we release the carburetor.

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Do not forget that its design is quite complicated, so it is worth removing all the elements with increased accuracy. The carb content is made up of a large number of small parts that can easily be lost.

After disassembling, it is necessary to diagnose the mechanism, replace deformed or worn parts, and clean and dry the entire kit. Make sure that the air filter is not clogged with dirt and dust. Then reassemble in the reverse order.

Carb adjustment

Precise work must be carried out exclusively on a hot engine. Therefore, start the engine and warm it up for 10 minutes. Then, turning the adjusting screw counterclockwise, stop the chain.

Before starting carburetor adjustment, lay the tool on a flat, hard surface. Point the saw headset away from injury. Remove objects that are near the cutting edges of the tool.

To adjust the carburetor, three screws are used, each of which has its own designation:

H. controls the main jet, designed to adjust the upper revs.

L. controls the idle jet, intended for setting low revs.

T. idle setting.

Adjustment is carried out with screws “H” and “L”. To lower the octane number of the chainsaw, the controls scroll from left to right (clockwise). This procedure allows you to increase the engine speed. To increase the octane number, the screws scroll in the other direction, from right to left. Thus, low revs are set.

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The adjustment sequence is as follows: L → H → T.

Scrolling to the maximum screw “L”, from left to right or in the opposite direction we find the limit number of rotation. Then we return to ¼ turn.

On a hot engine, in the same way, we perform actions with screw “H”. Let the saw run for a few seconds. Armed with a tachometer or good hearing, we determine the maximum speed indicator by sound. It must correspond to the value specified in the instrument passport.

If the circuit is idling, turn the “T” knob in the same direction until it stops completely.

Draw your attention to, that in the case of inaccurate determination of the RPM by the “H” regulator, the engine will fail and it will require expensive repairs that take a lot of time.

Idle adjustment is carried out by screw “T”. The knob rotates counterclockwise (from right to left) until the chain stops completely.

With the correct carburetor adjustment, you should observe:

Fast acceleration of the engine.
A distinct motor sound, like on a four-stroke mechanism.
Lack of chain movement at idle.

We hope that our article helped you solve such a problem as adjusting the carburetor of the chainsaw, and you can carry out this maintenance yourself. If you have any doubts during the adjustment process, then it is better to entrust this process to the employees of a specialized service center, where there are all the necessary components for the repair of equipment.