The carburetor chainsaw is a device that is responsible for the supply of fuel into the engine combustion chamber. From how correctly it works, not only the power and efficiency of the operation of the instrument depends, but also its economy.

Adjustment of the carburetor chainsaws are rarely carried out: basically the factory setting is optimal for normal operation. But if necessary, adjusting screws rotate more accurate adjustment. We will understand more, in what cases you have to do it.

When it is necessary to adjust the carburetor chainsaw

First of all, this procedure must be done when weakening adjusting screws. In addition, there are other signs that testify that the carbusopile carburetor is required:

• damaged protective cap;
• there is a strong vibration;
• significant wear piston (in this case, the engine repair is also required, but the repair of a carburetor chainsaws, as a temporary measure, is able to make the work of the unit more stable);
• in interruptions of the engine operation associated with the clogging of the carburetor (the flushing is also required);
• the engine is either not at all start, or it stalls immediately after the start (the reason is the depletion of the working mixture);
• significant increase in fuel consumption and abundant exhaust (this happens with incomplete combustion of the fuel mixture).

Preliminary procedures

The carburetor device chainsaws is fundamentally similar in all models. However, depending on the manufacturer, some differences in adjustment schemes exist. The main goal is to change the quality and amount of fuel and air mixture entering the engine combustion chamber.
The following rules must be followed during operation:

• the chain should be directed towards avoiding injury;
• the tool should be put on a flat, steady pad (table, rack), and cutting edges should be at a safe distance from any items.

It should be known that almost any carburetor is regulated by three screws.

1. Screw, managing the main jet and labeled "H": It is responsible for maximum turns.
2. Screw with the designation "L": it controls the idle jush on the small turnover of the engine shaft.
3. The idle mode adjustment screw (different manufacturers use their designations, for example: "S", "La" (STIHL), "T" (Husqvarna), Partner).

In some cases, adjusting screws in the carburetor are less, in such a way, manufacturers try to simplify its adjustment.

Important: Before you proceed to adjustment, you should study the instruction manual, where the angles of rotation of the screws should be indicated. This is an important condition for the safety of engine operating parameters.

 

The entire process of adjustment can be divided into two stages:

• basic (when the engine is turned off);
• final (performed on a heated engine).

How to adjust the carburetor on a chainsaw: the basic stage

Adjusting screws of minimum and maximum revolutions (indicated "L" and "H", respectively) should be slowly wrapped until it stops clockwise, after which they need to be turned back to one and a half turn.

How to set up a carburetor on a chainsaw: the final stage

1. For 10 min, engine warming is carried out on medium turns.
2. Screw ("S", "La", "T", Partner) idling adjustment is rotated counterclockwise until the engine enters the steady operation mode. The chain should remain stationary. If the engine stalls in idle mode, the adjusting screw is required to be tricking clockwise. If the movement of the chain is observed - the screw is twisted against the clock.
3. Verification of engine operation in maximum revolutions mode and during acceleration.

Check acceleration

It should be assumed that the engine operates normally in the acceleration mode, if during a smooth pressing on the speed accelerator increases to the maximum value (from 2800 to 15000) in a short time. Otherwise, it is necessary to unscrew the screw with the marking "L" for a maximum of 1/8 turns counterclockwise.

Adjusting the maximum number of revolutions

For this purpose, an adjusting screw with the designation "H" is designed. By rotating it clockwise increase the revolutions, and the rotation in the opposite direction is reduced. It is necessary to set the maximum rotation frequency within 11500 - 15000 rpm. Exceeding threatens the fact that the engine will work "Voznos" and there will be disorders during the ignition process. The rotating screw "H" should be focused on how the ignition occurs. With the advent of failures, the rotation clockwise should be stopped and returning a little screw counterclockwise.

Re-checking at idle

After adjusting the operation of the carburetor in the acceleration mode and at maximum revolutions, it is required to check the operation of the tool in the idle mode. If the adjustment is performed correctly, these conditions will be followed:

1. The chain in idle mode remains stationary.
2. The engine is quickly gaining momentum when pressed on the accelerator.
3. The sound of the engine should be similar to a four-stroke unit.

If the above conditions are not fully respected, the adjustment of the carburetor (excluding the base stage) should be repeated. The lack of experience in the adjuster can cause the progress of the node. If it is impossible to configure, it is recommended to apply for help from professionals to achieve stable operation.

In conclusion, the video process of adjusting the carburetor chainsaws STIHL MS 250.