Device and principle of operation of the carburetor of a modern chainsaw, a description scheme

Carburetor. A node of the chainsaw, which is responsible for supplying fuel to the engine, the quality of the work of all other mechanisms depends on the correctness of its operation, which ultimately affects performance. In this article, its device will be examined in detail, purpose. The main malfunctions are also considered and recommendations are given to eliminate them.

Carburetor is the main component of gasoline internal combustion engines. This is the device with which the mixing of gasoline with air occurs. As a result, a combustible mixture is formed that ensures the operation of the engine. All the work of the chainsaw is based on it, because through this node fuel is prepared for further admission to the combustion chamber.

Carburetors of chainsaws are membrane and float.

When working chain chainsaws, it is necessary to constantly turn them at a certain angle, so there was a need to create the best option. Engineers created a membrane. A model of a carburetor, which is specially adapted to strict working conditions. She can work even in an inverted form.

Old models, such as friendship, the Urals could not boast of such an option. The user was forced to resort to various tricks to turn the saw and at the same time maintain its performance. Such saws were equipped with a special mechanism, which allowed to separate the tire itself separately, setting it with a horizontal or vertical direction.

How the carburetor is configured?

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

chainsaw, carburetor, works

  • The engine heated to the operating temperature (it is mandatory only on the heated engine, this will allow you to get a more accurate adjustment).
  • Engine adjustment for uninterrupted operation at low speeds.
  • Carburetor setup for the correct supply of the fuel mixture in maximum speed mode.
  • Accurate control of the carburetor to work in idle mode.
  • Checking the chainsaw in all modes.

Almost all carburetor models have three adjusting screws.

  • Screw (t) is responsible for accurate setting in idle mode.
  • Screw (h) setting work at maximum speeds.
  • Screw (l) regulates the formation of the mixture at low speeds.

Twisting the screws (l) and (h) the supply of fuel and the mixture is impoverished, respectively, the turns increase.

Carburetor adjusting screws L. Minimum revolutions and h. Maximum engine speed.

Now let’s look at how the correct adjustment of the chainsaw carburetor takes place in more detail.

What is the mature of the chainsaw

The considered units of modern chainsaws differ in design from old.Style devices. Over, this difference lies not only in the design, but also in the principle of action. But first things first. To begin with, we learn the main components of the mechanism, and then we will figure out the principle of the functioning of a chainsaw carburetor.

Structurally, a chainsaw carburetor can be divided into three parts:

  • Gas tank fuel suction chamber. This camera is associated not only with the gas tank through the fuel supply, but also with the design of a crooked-shaped mechanism. This part consists of two fittings, a membrane for pumping fuel, two valves, filter and transport channel
  • The fuel mixture accumulation camera and its receipt to the channels of idle, medium revolutions and maximum revolutions. This camera consists of a needle or needle valve, membranes for opening a needle, fuel accumulation chambers, adjusting screws, maximum revolutions, as well as channels of XX and medium.Speeds, which are always open
  • The working area is the main area in which air mixing with fuel occurs and the flow of this mixture into the combustion chamber. The main working elements of the working area include the shutters (air and throttle), as well as a diffuser, in which fuel and air mixing occurs

Adjustment of the chainsaw carburetor instruction

Setting up the chainsaw carburetor begins with the preparation procedure. The preparation is based on the implementation of such actions:

  • Check the air and fuel filter for the presence of contaminants, and if any, you need to clean these elements
  • Make sure the absence of damage to the membrane
  • The health of the needle valve
  • Lack of air leaks, which can occur due to the leaky oil seals, gaskets and seals

After making sure that the carburetor is working, you can adjust it yourself. You can restore the performance of the mechanism to factory settings, but it is not always necessary to do it. Instructions on how to adjust the carburetor on the stihl, Husqvarna, Makita chainsaws, Dolmar, Champion, Sadko and others, described below. Initially, we find out why each screw is intended for the device:

  • Screw h is the main nozzle that is responsible for setting the maximum number of tools of the tool
  • Screw l. A jackler of xx, which is needed to install low.Speed.Strokes
  • Screw la or s or t. An increase and decrease in the amount of mixture supplies to the cylinder

It is interesting! There are mechanisms on which there are two or even one adjusting screw called LD for air supply (on the Stihl 180 and 170 chainsaws). This is done in order to simplify the process of adjusting the gasopyle carburetor unprofessional.

Each type of stihl, Husqvarna, Makita, Dolmar, Partner instrument is an instruction that has a section where this process is described in detail. It will not hurt if before setting up, you will find instructions and read it before twisting the screws.

Preparations for setting up the gasopyle carburetor include the following manipulations:

  • DIY chainsaw installation on a flat surface. It is also recommended to fix the tool so that it does not move when exposed to screws on the screws
  • Direct the tire away from yourself
  • Ensure a safe distance for others, since adjustment of the carburetor of the chainsaw is carried out on a working engine
  • It is not necessary to extract a carburetor from the unit for its configuration

2-Stroke. ‘How Engine Carburettor Work Together’. Chainsaw/Trimmer/Lawnmower/Stihl/Husqvarna

The process of setting up the chainsaw mechanism:

  • Warm up the engine, letting it work for 10 minutes
  • Find the location of the screw l and using the screwdriver we rotate it in one and the other. Upon rotation, an increase in revolutions will be observed (the engine will work louder) and a decrease (when rotating in the other direction)
  • We determine the optimal value of revolutions, which should be 1.5-2 thousand revolutions. It will be problematic to determine the newcomer by ear, so you can connect a tachometer. Details about the connection and use of the tachometer are described here
  • After choosing the optimal speed value, you need to turn the screw L to 1/8 or ¼ turn (indicated in the documentation for the unit) counterclockwise, and click on the accelerator button. If the engine responds instantly and evenly, that is, it gains speed quickly, then you can continue the procedure. If the failures are found, then the speed should be reduced, and again repeat the check by the accelerator
  • If after these manipulations the chain on the unit does not move, then you need to smoothly begin rotation of the screw t or s clockwise. Move the screw along the time of the clockwise you need to until the chain starts to move
  • As soon as the chain begins to move along the tire, you need to twist the t or s screw back to a quarter of turn
  • The chain must stop the chain. If it continues to move, then you should also twist the screw s. Ideally, the chain should not move at the idle speed of the unit
  • The motor with a configured carburetor should work evenly, and when you press the gas button, the speed should increase sharply. With uneven operation of the motor, you need to repeat the settings from the screw L, checking it for 1/8 turnover counterclockwise. After that, the process of moving the screw S is repeated, on which the adjustment of the gasopyle carburetor is completed

The regulation process is not finished on this, but the tool can already be checked in action. For beginners and inexperienced sawmills, it is recommended to complete the setting process on this. For a more accurate adjustment of the carburetor of the chainsaw, you need to set up maximum speeds. We proceed to setting the screw H for experienced sawmills:

How to tune a chainsaw carburetor

  • Determine the enrichment of the mixture by exhaust. To do this, we develop the turnover to the maximum, and look at the nature of the exhaust. The presence of brutal smoke and a strong vibration of the tool indicate excessive enrichment of the mixture
  • A tachometer (if it is connected) will show a large number of revolutions. More declared in the characteristics
  • To reduce maximum speed, you need to move the screw h by several revolutions counterclockwise
  • The maximum revolution is re.Conducted, and the process is repeated again if necessary

It is interesting! You can determine the depleted mixture by such signs as screaming of the motor, its rapid heating, interruptions in ignition and detonation. It is impossible to allow the depleted mixture, since it will lead to a rapid failure of the cylinder-piston group.

Make sure that the tool is correctly configured by the following signs:

  • The chain at idle does not move
  • The engine works like a four.Stroke motor
  • When you press the gas handle, a quick response of the motor and a set of revolutions occurs

To make the most only possible setting, you will need to use the wired or wireless tachometer.

On the Stihl 170 and 180 chainsaw, the tuning process of the chainsaw carburetor looks somewhat simpler, since there is only one screw there. A detailed description of the process of regulating the carburetor on the Stihl MS180 chainsaw is shown in the video.

How the carburetor of a chainsaw of a membrane chainsaw works

The membrane carburetor is assembled from 20-30 parts, depending on the model. They include fastenings and gasket screws, as well as 17 functional elements. The principal device is shown in the scheme below.

  • A fittings under the gas tank for supplying gasoline.
  • The channel through which the fuel is pumped when pressing the primer button (sucker) when starting a cold engine.
  • Inlet valve, which overlaps when filling the camera.
  • Sungee membrane.
  • Fuel exit valve from a membrane chamber.
  • Mesh filter.
  • Rotary damper that controls the supply of air from the air filter.
  • Throttle (gas) damper, which regulates the supply of fuel mixture in the combustion chamber.
  • Fuel supply channel.
  • Idle speed adjustment screw.
  • Needle regulating the amount of fuel-air mixture.
  • Holocaucus nozzle.
  • A membrane that determines the position of the needle and the number of incoming mixture.
  • Fuel chamber.
  • The main jet.
  • Camera-Diffusor where gasoline mixing with air occurs.
  • Work speed adjustment screw.

The carburetor provides engine operation in 3 modes:

With a cold start, manually pressed the primer button (sucker). At the same time, the pump membrane 4 is compressed and revealed. A vacuum is created, and due to it there is a direct pumping of gasoline, from a tank to the fuel channel of the carburetor. This accelerates and facilitates the launch of a cold engine after a long downtime.

Then, when operating the engine, the vacuum is created already due to the course of the piston in the combustion chamber. Fuel begins to be sucked from a gas tank into a carburetor through a fitting 1. This happens until the camera 14 is filled. When filling from the pressure of the membrane, it changes its position and through the rocker presses on the needle 11. The needle rises and covers the fuel supply. Due to this, it is excluded overflowing the fuel into the diffuser and then into the combustion chamber.

After gasoline from the chamber 14 goes into the diffuser and then into the combustion chamber, the membrane bends, changing the position of the needle, and the fuel supply resumes until the camera is filled.

The cycle is repeated. Thus, in chamber 14, the amount of fuel is always the necessary for the engine and tightness, which ensures the flow of fuel into the combustion chamber due to the vacuum from the piston course.

When the gas handle is pressed, the throttle is opened, the supply of the fuel mixture in the combustion chamber and engine speed increases.

In the idle mode, the damper is closed, and the minimum amount of fuel comes through a slot at the bottom of the damper. The amount of incoming fuel, and therefore the frequency of idle speeds is regulated by a screw 10.

There are models of carburetors where the frequency of idle revolutions is regulated by the position of the throttle. The adjusting screw in this case regulates the supply of fuel through the channel, but the position of the damper.

To consolidate the information read, we recommend that you watch the corresponding video, the author of which tells in detail and shows the device and principle of operation of the chains’ membrane carburetor. In the course of the story, the author covers the main problems, malfunctions. Pretty useful video on this topic.

How to remove a carburetor from a chainsaw?

Or the engine does not start or immediately stalls, most likely, the carburetor was clogged and needs to be cleaned. How to check the gasopyle carburetor? Will have to disassemble. Otherwise it will not work out in any way.

Before cleaning the carburetor on a chainsaw, it is still recommended to check other nodes: air and fuel filters, a candle of ignition and a silencer. It is possible that it was they who were clogged. It is easier to clean the filter or replace the candle than to clean the carburetor on the chainsaw. By the way, it is the problem with the candles that is the reason why the chainsaw shoots at the carburetor. Too later the ignition leads to the fact that an excess of the fuel mixture is formed, since it does not have time to burn completely.

In the event that the problem is not fixed, you will have to remove the carburetor. To do it is very simple:

  • Remove the plastic back cover. It holds on a fixer or on the thread.
  • We dismantle the air filter.
  • With a flat screwdriver, you need to put air rods and remove them. There can be two or three rods, depending on the model.
  • The carburetor is attached with two mounts. They are diagonally. We need to unscrew them.
  • Disconnect the gasoline hose along which fuel is supplied to the gas tank carburetor.

How to adjust the carburetor on the chainsaw Husqvarna 365

There are three screws for adjusting Walbro HD 6B on the carburetor case:

The tuning of the Husqvarna 365 chainsaw carburetor can conditionally be divided into two stages: preliminary tuning, accurate tuning.

Husqvarna 365 chainsaw carburetor adjustment can be made through special holes in the case of the saw itself (the location is noted in the photo above).

Preliminary setting. At the manufacturer during the testing of the chainsaw, the main adjustment of the carburetor is performed. The basic setting is as follows: h. 1 turnover, l. 1 turnover.

After buying a chainsaw, it is necessary to carry out a full engine running. For this, it is necessary that the engine work on a rich mixture for the first 4 hours. To ensure this mode, it is necessary to configure the maximum speed by 600-700 rpm below maximum, this is about 11800 rpm.

On a note! The maximum speed of the Husqvarna 365 chainsaw should not exceed 12500 rpm, the violation of this requirement will entail increased wear of the cylinder. Piston group and even its failure.

Accurate setting. After running in the chainsaw, it is necessary to conduct an accurate setting of the carburetor. First you need to configure the screw l, then the screw t and only after that the screw h. Before setting, it is recommended to start a chainsaw engine and warm up for 10 minutes.

chainsaw, carburetor, works

The algorithm for the exact adjustment of the carburetor is as follows:

  • We set up a jet. We try to find the maximum rotation of the engine by turning the screw L clockwise or against (for a more accurate definition, you must use the electronic tachometer). Когда нужные обороты будут найдены, отворачиваем винт L на 1/4 оборота.
  • Set the idle speed of the engine with a screw t. Turning the screw t, we find idle speed recommended by the manufacturer. 2700 rpm. When the revolutions are found, we turn the screw t until the chain stops rotating. It is necessary to achieve such a mode when the engine starts to work smoothly from any position, and when the throttle is released, the chain ceases to rotate.
  • We set up a nozzle h. Turn the screw h until it stops and turn it out for 1/4 turnover. Let the saw work at maximum speed for 10 seconds. We follow the nature of the sound. If I drank at full speed, the mixture is too poor. In this case, the screw h must be unscrewed by another 1/4 turnover. With the correct setup of the chainsaws at high speeds, slightly “four” (the sound of the exhaust is similar to the sound of a four.Stroke engine). If the saw is strongly “fades” and smokes strongly, then the mixture is too rich. In this case, the screw h must be slightly twisted. We twist the screw h until we achieve the correct sound of the engine.

When the carburetor is correctly configured, the chainsaw works evenly and slightly “four” at full engine speeds. The chain does not rotate at idle. With a sharp opening of the throttle, the saw is gaining momentum smoothly, without failures.

How to adjust the carburetor on a chainsaw correctly?

To configure the node, install the tool on a solid even surface. It is best to regulate the gasopyle carburetor in a place protected from dust and moisture.

The process of setting up the node should look as follows:

  • First you need to unscrew the fasteners and remove the protective file of the saw. This will allow you to inspect the carburetor and, if necessary, clean it;
  • Next, you need to extract the standard tool air filter. If the saw is equipped with an additional foam insert, then it also needs to be removed;
  • After that, you need a screwdriver, which needs to tighten the bolts with the labeling h and l clockwise until it stops. You need to do this very carefully so as not to break the bolts;
  • Then both screws should be unscrewed by 1.5 turns in the opposite direction;
  • Next, you need to start the chainsaw motor and let it work for about 7 minutes;
  • As soon as the motor cylinder heats up, you will need to start turning the Bolt B to the moment until the ICE becomes at maximum speeds. Immediately after this, the bolt must be turned into 1/4 turnover in the opposite direction;
  • Then you need to configure the operation of the motor at high speeds. To do this, you need to connect an electronic tachometer to the engine, and start turning the bolt H until the indicators on the device’s board coincide with the instructions for the recommended maximum speeds in the instructions for the saw;
  • At the end, it remains to set up the work of the internal combustion engine at idle. To do this, you will need to slowly twist the t bolt against the watch arrow until the engine becomes stable and without failures. If the motor began to stall, then the bolt t should turn in the direction of the watch arrow.

To configure the carburetor on the chainsaw, you should work as accurately as possible with adjusting bolts. Excessive twisting of the screws will lead to an increased load on the engine and other important nodes of the garden tool.

Yak correctly launched a carburetor of a chainsaw?

Belshist of the models of the carburetor of the gasoline drank three Gwinti reguluvannya:

Glorious parameter is the way, the Tsih Gvintiv wrap.

For an accurate carburetor lamb frying, frying tachometer. Vin to allow the vanity of the Obteri of the Dvigun chainsaw.

The base of the carburetor regulating

Gwinti H Tu L is not at one time for an hourly tan to the stop, and Potim vicrutiti for 2 wrappers in the giking side. Tse Standard Order of the Primary Council of Popular Models of Chainsaws. Takozhi.

Regulswoman of idle

In Pershu Cherga, Treasel Vidshukati, in the way, in the yakut nashchi idle wrap, turning gvint l. Kolya vi, behind the pre.Nostalum of the tachometer, you know the position of the position, Trustly turn Gwint of the Nizyki Obertiv (L) on the check (1/4) Office. Lancyug was chainsaw at the cum. Yakshcho Ts Vidbuvay, Treasel Vruchuvati Guint idle (t) opposed the hour of the case, the otystyuye navigation did not stop rubbing.

Yak Nalastuvati maximum wrappers of a chainsaw?

Shcho Zmіnity maximum wrap. Yakshcho Krachuvati Gwint, Oberti will be Vishche, and Yakshcho Vidkruchuvati. Nizhge. Yak Rule, Nyabilsh let the number of Obertiv Dvigun collates in DIAPAZONI 11500-15000 on Khvvin. Yakshcho to the prazuvati with a foul number, the problem of the shock. In such a vipad, Guint Trochi.


Yakshcho Natisnuti on the gas.Rosopi gas button, the Dvigun is guilty. Tse dashingly. Yakshcho iztrument is the wrap, Trokhi Vidkrutiti Gwint L, not more, NIZh for 1/8 wrapper.

If the lalastuvannya is Zakinchenen, Treaselly Trick Perekiti Robot was chainsaws on the idle of the wrappers. The Dvigun was guilty of the Praitsevati, and Lancyug. Fluttered Neuruhomim. Yakshcho Dvigun Prazuu unbearably abundant Lancyug, to repeat the reguluvannya, dropping the ETAP of the basic lamb.

Nuance, about yaki Trratіno Pam’yatati in the process of launcher

Do not shit Guint Nizyki Obertiv (L) Nadto very much to the Gwintic of the Tysuquate Obertiv (H). Tsna to the cause of the supra.Winner to the Dvigun Zbidneno Sumyshi (Nadto Bagato VITROUS BEAUTY BAST). Yak naslіdok, Porshneva wake dry pir hour of Roboti, he is very heated.

Painfully for all the smell of the elaboration of the Powanthous of the Gwintiv carburetor, the skew is to fill the Snow Snow Glorov to the factory launcher, Yakshcho saw Rapta not to start the abdoma of pratsyuvati unnecessary.

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