Dismantling the Stihl 180 Chainsaw

Dismantling the Stihl 180 carburetor

To begin with, it’s worth deciding why, in general, you may need to adjust and repair the stihl ms 180 carburetor. So, you need to do this in the following cases:

  • if the chainsaw does not keep idle;
  • repairs may be required if the saw does not start;
  • there is a loss of power;
  • excessive fuel consumption;
  • chainsaw does not develop the highest speed.
  • stalls at speed.

This list can be continued for a long time, but we have identified the main premises. Before proceeding with the adjustment, it is necessary to know what are the main parts of the carburetor on the Stihl 180 chainsaw, and who produces it.

So, the stihl ms 180 carburetor is designed and manufactured by a subsidiary of Stihl, under the name Zama. Stihl 180 chainsaw dismantling part 3. duration: adjusting the chainsaw carburetor. Stihl 250 chainsaw adjustment and carb adjustment. Unique carburetors on their case have a company logo guaranteeing product quality.

The carburetor of the Stihl 180 chainsaw, indiscriminately, can only be adjusted by the number of revolutions at idle. It is impossible to increase or decrease the fuel supply in various modes with the help of special screws. Stihl 250 chainsaw stalls when pressed on gas, c. The manufacturer restricts access to adjustments and does not install these screws. How to adjust the carburetor to the correct idle speed is very painstakingly described in the manufacturer’s instructions.

In the event of certain flaws and experience, it is possible to increase or decrease the fuel supply by increasing the gap when opening the needle valve.

To increase the feed, the rocker of the needle valve in the distribution chamber must be bent up, and to decrease, down. This regulates the stroke of the needle and, accordingly, the throughput of the valve.

It is not necessary to carry out the adjustment without the help of others, since this must be done very accurately and if the error is returned, the initial position of the rocker arm is almost impossible.

After we examined the carburetor device, finding the reason why the fuel enters the combustion chamber in a larger volume is not difficult. This happens due to wear on the gasket between the compensator cover and the carburetor body. Adjusting the carburetor of the Stihl 180 chainsaw, a video tip to which you can see. You ask how it can affect?

The answer is simple, shrinking, the gasket releases the diaphragm located on top of it a fraction of a mm down. She, in turn, will press harder on the rocker of the needle valve, it will open more than expected and the fuel will go in excess (begin to overflow).

Another reason is the extension of the diaphragm itself, this ultimately occurs due to natural wear. To prevent this process is unrealistic, but you can solve the problem by periodically changing all gaskets, carburetor diaphragms, and the fuel pump. If your chainsaw starts sneezing and starts up poorly, then the time has come to adjust the carburetor on the Stihl 250 chainsaw with your own hands. There is a repair kit for this.

A common cause of failure of a carburetor on a Stihl chainsaw is sticking of the valve in the nozzle. The cause of sticking is a violation of the storage of the chainsaw, or rather the manufacturer’s instructions Stihl 180 on proper preparation for storage.

As follows from the instructions, before long-term storage, it is necessary to drain the fuel from the tank, then start the saw and burn gas from the carburetor. Stihl 180 chainsaw. the device and carburetor adjustment of the Stihl 180 ms 230, ms 250 chainsaw. Failure to follow this usual rule entails the following consequences.

The forsknui valve, being in a certain contact with the fuel, sticks to the body, since gasoline gradually evaporates and only sticky oil remains. It is impossible to change the nozzle, because they are not in the repair kit, you can only try to knock it out and rinse, which can not always be done without spoiling the nozzle.

In order to blow, change gaskets or a needle valve, the carburetor must be disassembled. To do this, unscrew the 4 screws on the compensator cover and one on the fuel pump.

Having opened the case, it is worthwhile to be as discreet as possible, because if debris enters the carburetor inside, it will make its work impossible. The thickness of the channels in it is comparable to the width of a thread or even a human hair.

Video on the repair of the carburetor Stihl 180, you can see below. In it, the master carefully knows about the dilemmas and clearly shows the entire repair process.

Trimmers and Chainsaws

Chainsaw carburetor adjustment with STIHL MS 250 as an example

The necessity of the operation “Adjusting the carburetor of the chainsaw” is determined by the color of the spark plug electrodes: if black. means re-enrichment, if brick-gray. means the norm, if white coating on the candle electrodes means lean mixture.

The main role in adjusting the carburetor of the Stihl chainsaw is played by the upper screw (closest to the muffler).

According to the factory parameters (indicated on the cover of the chainsaw), it must be unscrewed by 1 revolution, and then it is necessary to correct it. if you unscrew it, the working mixture is enriched (more gasoline enters the air-fuel mixture), if this screw is screwed in, the working mixture becomes leaner (less gasoline gets into the air-fuel mixture).

Before adjusting the carburetor of the Stihl chainsaw, it is necessary to carry out maintenance of the chainsaw (cleaning the carburetor of the chainsaw, washing the engine of the chainsaw, replacing the spark plug, cleaning the air filter, checking the chain tension, adjusting the idling speed, warming up the engine).

1. Screw the screws “H” and “L” (on the muffled chainsaw) as far as they will go, and then turn them both out 1 turn. 2. In this video we are adjusting the carburetor chainsaw Stihl ms 250 repair. Start a chainsaw and warm it up. Carburetor Chainsaw Adjustment Carburetor Adjustment Doesn’t Need a Stihl 180? Causes. Adjustment of carburetor chainsaws 180, 230, 250 and others.

Give full throttle and use the “H” screw to achieve a maximum engine speed of 14,000 rpm. by tachometer (by engine speed counter). Maximum revolutions for adjustment to keep no more than 10 seconds! 3. What distance should the starter from the poles to the module ?, what is the correct carburetor adjustment for the chainsaw ?, Stihl 250 ms.

Use the “LA” idle bolt to make the chain begin to move, and then turn this bolt ¼ turn counterclockwise.

4. If, after this adjustment of the chainsaw carburetor, the idle speed is not stable, and the chainsaw does not accelerate well, then you need to turn the “L” screw a little counterclockwise until the chainsaw starts to gain speed and work well at idle. I adjusted the Stihl 250 chainsaw carburetor with my own in this video. Then correct the bolt “LA” (idle tachometer should be 2800 rpm).

Note: It is not possible to adjust the carburetor of the chainsaw if there is air leakage into the engine from the side (through the gasket under the carburetor, through the accelerator pump of the carburetor, through the oil seals of the crankshaft of the chainsaw or elsewhere).

DIY carburetor setup for chainsaw

For an independent carburetor option, it is necessary to familiarize yourself with its device and clarify the procedure for the work that is carried out to adjust the parts responsible for the proper functioning of the component parts of the device and parts close to it.

It is necessary to carefully handle objects for the system option, and also determine the compliance of the set characteristics with very acceptable values.

The carburetor is used to mix the combustible mixture with air in compliance with well-established proportions. If clear doses are not respected, the health of the motor is at risk. When a huge amount of air enters during the mixing of the component, and there is not enough fuel, such a mixture is considered to be “poor”.

It should not be allowed and oversaturation, because with a large amount of fuel in comparison with air, malfunctions or deterioration of the motor are also likely. Do-it-yourself Stihl 180 chainsaw repair. 142, 240, 365 do-it-yourself videos. video. Adjustment of the carburetor is necessary not only before the initial implementation, but also when any differences in its work are revealed. Before working with a chainsaw, do not forget to run it in.

Carburetor parts

The carburetor design contains a standard set of parts, but may vary slightly depending on the manufacturer. Components:

  1. The foundation. DIY carburetor adjustment on. This is a special tube that visually resembles an aerodynamic design. Air passes through it. In the transverse direction in the middle of the pipe is a damper. Her position can be changed. The more it is pushed into the passage, the less air enters the engine.
  2. Diffuser. This is the lent out part of the tube. With its help, the air supply rate increases in the segment where the fuel comes from.
  3. Channels for supplying fuel. The fuel mixture is contained in the float chamber, then passes into the nozzle, from which flows into the spray.
  4. Float chamber. It is a separate structural element that resembles the shape of a tank. Designed to constantly maintain an optimal level of fuel fluid before entering the channel from where air comes.

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Each carburetor owner must have the necessary tools to adjust this system. There are three adjusting screws that are located on the device. They have their own markings:

Video: Dismantling the Stihl 180 Chainsaw

  • L. screw for low speed correction.
  • H. screw for adjusting high revs.
  • T. regulates idling, in most cases it is used for experiments.

Chainsaw Air Filter

Before adjusting the carburetor, you need to prepare the device:

  1. The engine warms up, that is, it starts about 10 minutes before repair, and turns off when work starts (see how to start a chainsaw).
  2. The air filter is checked and flushed.
  3. The chain is stopped by turning the T screw all the way (see chain oil).

So let’s get started!

What is still useful for you?

  • Firstly, an annotation on the operation of the device itself.
  • Secondly, a tachometer. Why specifically is it useful to us, we will examine a little later.
  • Thirdly, a screwdriver.

Surprisingly, this is all that we will need.

To get started, carefully familiarize yourself with the structure of your saw. What you need to do first is to find where the carburetor nozzles are, and even more important than the nozzles are the adjusting screws. Chainsaws “Husqvarna will help you learn how to adjust the chainsaw tips. Usually, there should be two to three screws. One of them regulates single turns, and two others. low and highest.

Specifically, they will need to be adjusted for you, or tightened, or unscrewed to enrich or impoverish the fuel mixture.

If you need to impoverish the mixture, then simply turn the knob clockwise, if enriched, then accordingly.

To adjust the idle speed, the screw that is responsible for this also needs to be twisted clockwise in order to increase the speed, or, as you might have thought, in the opposite direction, to reduce them.


But I want to warn you, be careful when setting up the carburetor. Therefore, as the depletion and enrichment of the fuel mixture, as well as the game with the speed, has very serious consequences.

When adjustment may be needed

When used properly, a good Stihl 180 chainsaw (or any other) should serve you well for a long time. How to start a Chinese Stihl 180 chainsaw. But everything happens after all.

The most common causes are:

  1. Loose fixing screws
  2. The engine was worn out (in this case, the adjustment of this chainsaw, like Goodluck, or the Sturm, will only help for a while, ideally it is better to immediately carry it in for repair)
  3. The carburetor is clogged (in this case, it will also have to be cleaned).

Distribution chamber

In the distribution chamber, as in the fuel pump, there is also a membrane that opens and regulates the fuel supply by pressing a special rocker, which lifts its needle valve with all this.

The chamber cover is the compensator case, which is mounted on the carburetor with 4 screws, a gasket is installed between the case and the cover, increasing the height of the chamber and responsible for sealing.

Step by step setup

The Partner 350 is regulated similarly to many chainsaw models.

In this model, we have three controllers:

  • Low RPM. L
  • High. H
  • Single. T.

After the release from production, these chainsaws are configured to receive the mixture more than necessary. This should only be in the first hours of operation.


When the engine warms up, it is better to reconfigure it. At idle, tighten screw T counterclockwise until the chain stops, after which we adjust each of them in the order: L, H, T.

The screw L must be turned counterclockwise орота turn at the moment when the largest turns begin at idle.

The screw H is regulated as follows: we heat up the kabryurator and turn it counterclockwise by ¼ turn. To determine if everything is in order, you need a tachometer. Turnovers should be the same as indicated maximum in the chainsaw passport.

Your actions should lead to the fact that the engine immediately accelerates and makes noise as four times.

The Husqvarna carburetor is configured similarly.

Partner 351 differs only in that its factory settings initially provide the optimal amount of the mixture, that is, everything should work correctly right away. How to get Stihl, the launch of the Stihl chainsaw, how to get the Stihl 180 chainsaw the first time you start the video. But, if necessary, the above instructions will help you adjust the carburetor correctly.

Before adjusting the UPT, you must make sure that both filters (air and fuel) are clean. In addition, there should be no air leakage into the motor from the side (through the seals, the gasket under the UPT or its accelerator pump, or elsewhere), otherwise it will not be possible to adjust the carburetor.

Dismantling the Stihl 180 Chainsaw

Preparing for carb adjustment

Almost any UPT is regulated by 3 screws:

  1. 1. The bolt of the main nozzle, designated “H” and used to set the maximum revolutions of the saw motor.
  2. 2. Idle jet bolt, designated “L”, used to set low revs. That is, for idle control.
  3. 3. The idle adjustment bolt, designated differently by different manufacturers: “S”, “LA” (Stihl), “T” (Partner, Husqvarna).

Carburetors with fewer adjusting screws are also found. So manufacturers protect their products from unprofessional interference and at the same time try to simplify their setup.

For safe regulation during its implementation should observe the rules:

  1. 1. The tool must be stably installed on a flat surface of a rigidly fixed object (workbench, rack, table).
  2. 2. The chain should be directed away from itself and others present.
  3. 3. There must be a safe distance between the chain and any surrounding objects, guaranteeing the impossibility of their mutual contact.

In such cases, adjust the carburetor on the chainsaw as follows. First, start the tool and warm it up for 10 minutes.

We begin the adjustment of the UTP by determining the position of the tuning screw “L”, at which the idle speed will be the highest. To do this, very slowly and smoothly turn this bolt one way, then the other. And so several times until the desired position is found. After that, we turn “L” 1 / 8–1 / 4 turns (the required value is indicated in the technical documentation for the tool) counterclockwise (hereinafter referred to as the PSD).

Then we continue to idle control using the screw “S” (“LA”, “T”):

  • If, after manipulating the bolt “L”, the chain is stationary, then it is necessary to smoothly rotate “S” (“LA”, “T”) clockwise (hereinafter referred to as PSR) until it starts to move. Then we twist “S” 1 / 8–1 / 4 turns back.
  • If the chain moves, rotate the “S” (“LA”, “T”) of the EMR until it stops, and then twist the “S” 1 / 8–1 / 4 turns in the same direction.

The engine should run evenly. And check it, how it accelerates. It is believed that the motor in acceleration mode works fine if, when you press the accelerator gently, the speed in a short time and without “dips” increases to its maximum value. If the engine does not work uniformly and / or accelerates poorly, then slightly. at a maximum of 1/8 of a whole revolution. it is necessary to twist the "L" frequency converter.

Checking the operation of the chainsaw

Now we check the adjustment of the adjusting bolt “H”. To do this, we accelerate the engine to maximum speed. Only for a long time it is impossible to drive it without load, you need to pause. We look at the exhaust and listen to the engine. If too much smoke comes out of the muffler, with bluish smoke, and the chainsaw makes a lot of noise, then the carburetor makes an excessively rich mixture.

When the chainsaw makes a screeching sound, the engine is very hot, the exhaust is accompanied by a crash and / or interruptions in the ignition are heard, that is, detonation occurs. the mixture is too lean, and the maximum engine speed is higher than it should be. This leads to overheating of the power unit, burnout of the piston, rapid wear of the cylinder and burnout of the plug. In this case, it is necessary to “H” turn 1/4 of the turn of the PSD.

At the end of the adjustment, we check the saw at idle. With a properly adjusted UPT, it should work like this:

  1. 1. The chain is stationary.
  2. 2. The sound of the engine is almost like a four-stroke.
  3. 3. Pressing the accelerator leads to a quick set of maximum speeds.

If these conditions are not fully complied with, use “S” (“LA”, “T”), as indicated above, or repeat the setting from the very beginning.

This is an approximate setting. For accurate, you need a tachometer. We do the same thing, just turn the adjusting bolts, focusing on the readings of this device. This will allow you to accurately and, most likely, adjust the carburetor the first time, depending on the model of the tool for working with the tree, set the idle speed at the level of 2800–3300 rpm or higher and the maximum. 11000-15000 rpm. Which ones should be set should be looked at in the technical documentation (operating instructions) for the saw.

After maintenance, such as disassembling and flushing, or previous unsuccessful attempts to set up this unit, it may turn out to be completely deregulated. So much so that the chainsaw will not start at all. In this case, it is necessary to configure the device of the engine power system in 2 stages, conditionally called:

  • basic. with the engine idle;
  • final. produced on a warm engine.

At the first stage, the adjusting screws “L” and “H” are slowly screwed in with the POPS until the stop. In this case, it is not necessary to make great efforts and try to tighten them. Then we turn both screws back. for many models I drank 1 revolution. And for some. by 1.5 turns. There may be other settings. This should be clarified in the technical documentation for the chainsaw. For some models, a hint is applied directly to the cover of their case near the adjusting screws.

This will carry out the recommended factory default carb setting. In this case, the screw "S" ("LA", "T") in no case do not touch, unless of course it has not been twisted. When he is already twisted, you have to work with him. Slowly screw in the “S” SPSF as far as it will go.

We pass to the final stage. We are trying to start the engine. If there were no manipulations with the “S” adjustment (“LA”, “T”) and exactly as recommended “L” and “H” are set, then it should start.

If the “S” had to be tightened for the reasons stated above, then the engine most likely will not start immediately. It will be necessary after each attempt to tighten this screw 1/4 turn POPS and again try to start the engine. In the end, he must earn.

Then warm up the engine for 10 minutes. If, after starting it up or during warming up, the motor is unstable or the chain starts to move, then slowly and carefully rotate the “S” (“LA”, “T”) of the frequency converter. As soon as the engine starts to work stably and / or the circuit stops, we immediately stop the adjustment. If the motor stalls, then turn this screw 1 / 8–1 / 4 (see technical documentation) of the RPM.

In the process of warming up, the idle speed can begin to increase, then, again, it will be necessary to “S” (“LA”, “T”) begin to slowly twist the PSRF until they become normal by ear. With the engine already warmed up, we continue to adjust the power supply unit, as described in the previous chapter.

Ural adjustment

It is slightly different in that it should not be carried out at sharp maximum revolutions, but to ensure that the chain picks them up quickly, but smoothly, without shifting along the tire.

In any case, it is worth taking the adjustment very seriously, because if you spend it incorrectly, the saw will not stay with you for a long time. Take care of your tools and if you are not confident in your abilities, it is better to take it to a professional.

Any of them, even strong Friendship, needs attention and care. And then the chainsaw will be your faithful assistant for many years to come.

When purchasing a HUS365 brand chainsaw, you should be prepared for the fact that after a month of using it, you will not want to deal with any kind of saw other than this brand. This is explained by its reliability, affordability, and most importantly. ease of management.

Throttle damper

A throttle is installed in the carburetor body and is responsible for increasing the supply of the fuel mixture directly to the engine cylinder. At the moment of pressing the gas, the throttle opens slightly, thereby increasing the channel capacity and fuel from the carburetor cavity, rushes into the cylinder in a larger volume.

The carburetor air damper is installed on the reverse side of the throttle and is responsible for starting a cold motor, its control is carried out by the motor control lever. For a cold start, the air damper is 100 percent closed, for normal operation open.

Removal and Installation Algorithm

In cases where the Stihl 180 carburetor needs to be cleaned or disassembled, for starters it will be necessary to remove the assembly from the chainsaw. Adjusting the carburetor of the Stihl ms 660 chainsaw. This must be done in compliance with a certain method of action:

  1. Attach a protective cover for the chainsaw to the tire.
  2. Remove the top cover of the chainsaw.
  3. Unscrew the two nuts securing the air filter and carburetor.
  4. Remove the air filter housing.
  5. Disconnect wire from engine control lever.
  6. Carefully pull the lever out of the landing position in the housing, immediately disconnecting the air damper rod from it.
  7. Pull the carburetor towards you and disconnect the fuel supply, also the throttle link.

To facilitate dismantling, you can additionally untwist the rear handle and disconnect the throttle rod at first from it, and later only from the carburetor. This may be necessary, because without certain experience, disconnecting the thrust from the carburetor is quite problematic and easier to first disassemble the handle.

Install the part in place, following the reverse order of the method.

When removing and installing the control lever of the chainsaw engine, you should be as careful as possible, because the landing place on the saw body is a weak link in the saw, and very often inexperienced users break it.