How To Adjust The Carburetor On A Stihl Chainsaw

Purpose, design and principle of operation of the carburetor.

The carburetor is needed to prepare the air-fuel mixture to power the engine. If the proportions in this mixture are not correct, the motor will malfunction. If the proportion is not observed in the direction of increasing the amount of fuel, the mixture is called oversaturated, if, on the contrary, there is little fuel, it is called lean. Both of them do NOT have the best effect on engine operation.

In different models of chainsaws, Carburetors differ in design, but they are similar in principle of operation. The air stream moves at high speed through the air channel. A damper blocking the channel allows you to change the speed of the air stream. The fuel is fed through the nozzle into the channel, where it mixes with the incoming air, forming a fuel-air mixture. The resulting mixture enters the engine.

The pressure in the float chamber, where the fuel is located before mixing, is practically equal to atmospheric pressure. But a vacuum is created in the air channel, due to which the fuel is drawn into the air stream. The more the damper is opened, the faster the air moves, and the amount of fuel also increases. the engine speed increases. So you can simplify the principle of the carburetor.

Chainsaw carburetor adjustment is required for efficient, smooth operation of the tool, getting maximum output and at the same time economical fuel consumption. Before adjusting, the fuel and air filters must be checked. they must be clean. On most chainsaws, adjustment is carried out with three screws: idle, high speed, low speed. In the correct setting of the carburetor, the following signs indicate:

  • The chain does NOT move at idle speed.
  • The engine accelerates smoothly and quickly.
  • The sound of the engine running is smooth, similar to the sound of a four-stroke engine.

Adjusting the carburetor must be treated with all possible care, because errors in the settings can lead to very serious consequences, up to the occurrence of engine malfunction. If you are not completely confident in your abilities, you need to contact the service center.

How to remove a carburetor from a chainsaw

Before adjusting, you need to remove it from the Stihl chainsaw. For this you need:

  • Return the retainer to the left to remove the cover.
  • Remove the filter, for which Unscrew the two nuts that hold it. For ease of use, it is recommended to use special screwdrivers with suitable bits.
  • Remove all rods, including the carburetor lever.
  • Remove the carburetor and then disconnect the fuel hose.

It is recommended to remember the location of the parts, so that you can then put the carburetor in place and at the same time there are NO extra fasteners or distortions and cracks.

Device and principle of operation

Before starting the adjustment, it is recommended to study in advance the device of the chainsaw carburetor. Most often, it does NOT depend on the model, the only exceptions are Chinese-made chainsaws. But you can always spy on the instructions.

The carburetor is the part of the chainsaw engine responsible for mixing oxygen and fuel in the correct proportions and feeding the mixture directly to the engine.

It is important that the proportions are observed, otherwise there is a risk of engine failure, which may be manifested by excessive fuel consumption or a complete stop of the device.

The main parts of a gasoline saw carburetor are:

  • Tube. performs the function of air transfer, portioned supply is possible due to the presence of a damper;
  • Diffuser. this part is located directly in the inlet, through which fuel is supplied, capable of accelerating the air flow;
  • The atomizer is capable of injecting gasoline into the created air stream;
  • The float chamber is a cavity that serves to maintain the fuel at the same level, from which gasoline is fed through a nozzle to the sprayer.
How To Adjust The Carburetor On A Stihl Chainsaw

The principle of operation of a chainsaw carburetor is simple. Its structure allows air to pass through the tube, while the speed can be controlled by a damper. After the tube is open, the float is activated. This causes the air to pass through the diffuser and mix with the fuel. Then this mixture moves into the cylinder. Due to the difference in pressure (in the chamber with the float, it is almost equal to atmospheric, and in the tube it is rarefied), the fuel is sucked into the tube, and the more there is, the greater the speed of the chainsaw engine.

Stihl 180 chainsaw carburetor repair

The main malfunctions of the Stihl 180 chainsaw carburetor include the following.

  • Gasoline is NOT going to the carburetor. A commonplace reason is the failure of the fuel pump. The diaphragm has lost its elasticity or is leaky. This happens due to material fatigue with prolonged use. As a result, when the engine is under vacuum, the diaphragm does not rise and does NOT open the fuel channel with the valve. It can be replaced with a spare one from the repair kit by disassembling the carburetor.
  • Gasoline may also fail due to a clogged filter element (mesh) in the channel between the fuel pump and the needle valve. It is also treated by replacing from the repair kit.
  • Carburetor overflows. It’s not hard to guess that the problem lies with the main camera. Dirt particles enter the cavity between the needle and the channel, i.e. The valve does not completely close the channel when needed and the chamber is flooded. Very often the membrane stops performing its function due to stretching (natural wear). As a result, when lowering, the diaphragm does not fully raise the needle, and fuel continues to flow. The main membrane is also included in the repair kit. It will NOT be difficult to replace it.
  • Very often, after a winter standstill, owners of Stihl 180 chainsaws are faced with a difficult start. In this case, the valve sticks in the nozzle. The manufacturer recommends burning the remaining gasoline into the carburetor before storing the chainsaw. Gasoline tends to evaporate and during long storage, engine oil remains in the carburetor, upon contact with which the injector valve begins to stick to the body. As a result, fuel does NOT enter the diffuser. Since the nozzle is not part of the repair kit, you have to knock it out and rinse it thoroughly. This must be done very carefully.
  • If the idle jet or the nozzle is forgotten, it is enough to blow them with compressed air. Or wash it in gasoline, in 90% of cases it helps. But you cannot use needles or wires, because. There is a risk of changing the flow area, thereby changing the throughput of the nozzles.

A common problem due to which the Stihl 180 is unstable is the loss of a retaining ring on the throttle shaft, as a result, it begins to wobble and play, which in turn leads to interruptions in operation.

So, you’ve decided to remove the carburetor and run a diagnosis. The withdrawal procedure is as follows:

  • Pull the gas trigger and lower the choke lever down. We turn the latch and remove the cover of the chainsaw.
  • We unscrew both fastening nuts with an 8 socket wrench and remove the air filter with the housing.
  • We remove the gas thrust (throttle valve) of the carburetor.
  • Disconnecting the cable from the control lever
  • We take out the engine control lever from its place. Disconnecting the air damper rod in parallel.
  • Pulling the carburetor towards you, remove it from the studs. Don’t forget to disconnect the fuel hose.

A more detailed and intuitive algorithm for dismantling the carburetor from the chainsaw is presented on.

As for disassembling the carburetor of the Stihl 180 chainsaw, everything is simple. 1 bolt is unscrewed on the fuel pump cover and 4 bolts on the main chamber cover. This is enough to change all the necessary components from the repair kit.

After disassembly, the carburetor must be rinsed in gasoline, and the channels and nozzles must be blown out with compressed air. In no case should the carburetor be blown out under high pressure and in the assembled state. Otherwise, you can stretch the membrane or diaphragm. Carburetor stops working properly.

In order to assess the condition of the filter mesh and membrane, you need to perform the following sequence of actions:

  • Unscrew the screw.
  • We assess the condition of the membranes, remove dust and dirt, and, if necessary, replace the membrane with a new one. Everything under the membrane must be clean. There must be no dirt on the membrane.
  • We check the condition of the filter mesh for the presence of dirt, if available, clean.
  • Putting everything back and disassembling the carburetor from the other side. Unscrewing 4 bolts, remove the cover, remove the membrane and assess the condition of the insides. In total you need to Unscrew 4 screws
  • To check the correctness of the fuel supply, putting the hose on the fitting.
  • We blow into it with our mouth, while opening the needle valve with our fingers, everything should work clearly.
  • Blow out 2 holes in the nozzles, with the same hose, they must puff calmly, without excessive effort. If necessary, it is enough to clean it with a conventional WD-40 cleaner.
  • Remove the jet-nozzle located on the right and clean it with a thin wire from the back.
  • Everything clean and collect. When installing the cover, be sure to fit it correctly. See the photo below.
  • As for the Stihl 180 carburetor repair kit, it includes a set of gaskets for covers, a diaphragm and a membrane, a needle valve, a rocker arm with an axle and a spring.

    How to adjust the carburetor on a chainsaw. all the secrets of correct settings

    Stable stable operation at any speed, developed power, efficiency, the use of technical capabilities in the amount provided by the manufacturer until now, and even the service life of a chainsaw. all this depends on its carburetor. In addition to the fact that this unit also needs to be kept in proper condition and serviced in a timely manner, it also needs to be properly adjusted. Setting up the carburetor of a chainsaw is not an easy thing, but with a leisurely, thoughtful approach and clearly following the instructions, it is feasible for almost anyone, and it should be carried out at the first sign of the need for this, and regardless of whether the new chainsaw is in operation or well-worn.

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    In the need to adjust the fuel supply unit (hereinafter referred to as the UPT, that is, the carburetor), the following reasons, symptoms and malfunctions indicate:

    • Factory or custom settings were knocked off due to loosening of the adjusting bolts and vibration, or in the process of unsuccessful attempts to adjust the carburetor again;
    • Damage to the HVAC housing cover;
    • The engine does NOT start or it starts up with an effort, and then stalls almost immediately;
    • The saw DOES NOT idle steadily or does not hold them at all;
    • Excessive fuel consumption and too thick exhaust;
    • Spark plug electrodes are black (over-rich mixture supplied to the engine) or white bloom (lean)
    • The saw does NOT develop maximum rpm or power;
    • The engine stalls during a set of revolutions;
    • There is a strong vibration of the chainsaw;
    • Due to irregularities in the operation of the air-cleaning system, particles of debris have entered the mechanism for distributing the air-fuel mixture;
    • In the piston group Significant wear. in this case, the DCC regulation is used as a temporary measure to make the operation of the tool more stable.

    Naturally, if dirt gets into it, the fuel system must be flushed. adjusting the carburetor cannot solve this problem. A worn out piston needs overhaul. However, in THESE cases, the setting is also performed.

    Chainsaw carburetor adjustment

    It may also be necessary to adjust the DCS even if the brand or quality of fuel, atmospheric pressure, humidity and ambient temperature, altitude above sea level changes (when the place of operation changes from a plain to a mountainous area, it is due to the rarefaction of air, and vice versa).

    Before adjusting the DCC, it is imperative to 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 oil seals, a gasket under the UPT or its accelerating pump, or elsewhere), otherwise it will NOT be possible to adjust the carburetor.

    Preparing to adjust the carburetor

    Almost any VAC is regulated by 3 screws:

    • 1. Main Jet Bolt, designated “H” and Used to set the saw motor to maximum speed.
    • 2. Idle Jet Bolt, designated “L” and Used for low speed setting. That is, to regulate idle speed.
    • 3. Bolt adjusting idle speed, designated in different manufacturers in different ways: “S”, “LA” (Stihl), “T” (Partner, Husqvarna).

    There are also carburettors with fewer adjusting screws. This is how manufacturers protect their products from unprofessional interference and at the same time try to simplify their customization.

    Before starting the adjustment, you should carefully study the operating instructions attached to the chainsaw, especially the part where the angles of rotation of the adjusting bolts are given. This is an important condition that will allow you to make adjustments without going beyond the operating parameters of the engine, correctly.

    For safe regulation during its implementation, the following rules should be followed:

    • 1. The tool must be stably placed on a flat surface of a rigidly fixed object (workbench, rack, table).
    • 2. The chain should be directed away from yourself and others present.
    • 3. Between the chain and any surrounding objects there must be a safe distance, which guarantees the impossibility of their mutual contact.

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

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

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

    • If the chain after manipulations with the bolt “L” is stationary, then it is necessary to smoothly rotate “S” (“LA”, “T”) clockwise (hereinafter POChS) until It starts to move. Then we twist “S” 1 / 8-1 / 4 turn back.
    • If the chain moves, we rotate “S” (“LA”, “T”) PRCHS until It stops, and then we twist “S” 1 / 8-1 / 4 turns in the same direction.

    The engine should run smoothly. And we check it, how it accelerates. It is considered that the motor operates normally in acceleration mode if, when the accelerator is pressed smoothly, the revolutions for a short time and without “dips” increase to their maximum value. If the engine runs unevenly and / or accelerates poorly, then it is necessary to slightly. maximum by 1/8 of a whole revolution. turn the “L” PRCHS. After that, it is necessary to make the above setting “S” (“LA”, “T”) again. We repeat these adjustments until the motor runs evenly and accelerates well.

    Chainsaw operation check

    Now check the setting of the adjusting bolt “H”. To do this, accelerating the engine to maximum speed. Only it is impossible to drive it for a long time without load, you need to pause. We look at the exhaust and listen to the engine. If there is too much gray smoke coming out of the muffler, and the chainsaw makes a lot of noise, then the carburetor is making an too rich mixture. In addition, the maximum speed of the power unit is lower than it should be. And also carbon deposits will form in it. In this case, it is necessary to slightly tuck the “H” POCH. Then again we check the operation of the engine and, if necessary, repeat the adjustment.

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

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

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

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

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

    After maintenance, such as disassembly and flushing, or previous unsuccessful attempts to adjust, this assembly may become completely misaligned. So much so that the chain saw will not start at all. In this case, it is necessary to configure the device of the engine power system in 2 stages, conventionally called:

    • Basic. when the engine is not running;
    • Final. done on warm up the engine.

    In the first step, the adjusting screws “L” and “H” slowly screw in the POPS until it stops. In this case, you do not need to make great efforts and try to tighten them. Then we turn both screws back. for many models, dust is 1 turn. And for some. by 1.5 turns. There may be other settings. This should be clarified in the technical documentation for the chainsaw. In some models, the tip is applied directly to the cover of their case near the adjusting screws.

    This will perform the recommended factory default carburetor setting. In this case, DO NOT touch the screw “S” (“LA”, “T”), unless, of course, it has already been turned. When he is already twisted, you will have to work with him. Slowly screw in the “S” PRChS until it stops.

    Let’s move on to the final stage. We are trying to start the engine. If there were no manipulations with the adjustment “S” (“LA”, “T”) and exactly as recommended, set “L” and “H”, then it should start.

    If “S” had to spin for the above reasons, then the engine, most likely, will NOT start right away. After each attempt, it will be necessary to tighten this screw by 1/4 of the POCHS turn and try to start the engine again. In the end he must earn.

    Then we warm up the engine for 10 minutes. If after starting it or in the process of warming up the motor is unstable or the chain starts to move, then it is necessary to slowly and carefully rotate “S” (“LA”, “T”) of the PRChS. As soon as the engine starts running steadily and / or the chain stops, stop adjusting immediately. If the motor stalls, then we turn this screw by 1 / 8-1 / 4 (see the technical documentation) of the POChS turnover.

    In the process of warming up, the idle speed may start to increase, then, again, it will be necessary to “S” (“LA”, “T”) start slowly turning the PRCHS until they become normal by ear. On already warming up the engine, we continue to adjust the power supply system assembly, as described in the previous chapter.

    After running-in on saws, only fine tuning of the DCS is performed. To do this, you will definitely need a tachometer and technical documentation for the dusting tool used. The fact is that almost optimal settings have already been set at the manufacturer’s factory. Just for running in the engine and grinding in the second moving parts of the chainsaw, the carburetor is set to prepare a slightly more enriched air-fuel mixture than the calculated optimal one. Due to this, the maximum speed is slightly lower than the manufacturer’s design and, in addition, the motor is better lubricated. Thanks to this, the engine running-in and the running-in of the remaining moving parts take place in a gentle mode.

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    Therefore, if there is no tachometer and / or reliable information (passport data) at the maximum speed and at idle, then it is not worth changing the factory settings after running in, since it will NOT work correctly. And in general, fine adjustment in this case is not necessary. the chainsaw will work fine with the existing basic settings. And if you really do it, then it’s better in a service center. It is recommended to entrust the jewelry tuning of the carburetor of a still completely new tool to specialists.

    It is strongly recommended to mark the previous position of the adjustment bolts as accurately as possible before making fine adjustments on your own. This will allow, in case of an unsuccessful attempt, to return them to their place. to the basic factory settings. We start with the bolt “H”. After setting the maximum speed, we check the idle ones. If they differ from normal, set them first with “L” and then with “S” (“LA”, “T”). In doing so, we are guided by the rules and principles set forth in the second chapter of this article. But we turn the adjusting bolts, focusing on the readings of the tachometer. Then we continue to tune the carburetor as described in the same chapter. The screws are steep, follow the tachometer.

    The carburetor of Stihl 180, 170 and other low-power chainsaws is adjusted with only one screw. “LD”. They are set to idle speed.

    The basic default setting is as follows:

    • 1. Fully tighten the “LD” PRChS to its tight fit.
    • 2. Then we turn it back POPS by 2 turns.

    If you need to make additional or other adjustments, then first you need to warm up the engine for 10 minutes. Then if:

    • Idling speed is too low. with a steep “LD” POChS, Until the chain starts to move, then turn this bolt 1/2 turn back, PRChS;
    • The tool chain moves at idle speed. slowly steep “LD” PRCHS until it stops, after which we turn this bolt another 1/2 turn in the same direction.

    And it is better to tune with a tachometer, Do not forget that the chain does not have to move at idle speed. The maximum idle speed of the Stihl 180 and 170 models is 13,500 rpm. Idle. 2800 rpm.

    Adjust the carburetor of a Stihl chainsaw equipped with a more powerful engine in the same way as described in the previous chapters. This also applies to such the most popular models as Stihl 210, 230 and 250. For basic adjustment (discussed in the third chapter), “L” and “H” after tightening are turned back 1 turn. There are also carbureted saws that have a basic “H” setting of 3/4 turn. By the way, this information is indicated on the instrument case cover.

    The angle (step) of rotation of the adjusting bolts during the DCT adjustment is 1/4 turn. Idle speed of the Stihl 210, 230 and 250 models. 2800 rpm, maximum no load. 13000 rpm.

    The cost of repair work and replacement of the carburetor

    If there is no experience in repairing parts of a Stihl chainsaw, it is better to entrust it to specialists. The price depends on the complexity of the repair and the region. The average values ​​are as follows:

    • Gasoline saw diagnostics. 300 rubles;
    • Replacing the carburetor. 300 rubles;
    • Comprehensive service (the complex includes flushing, installation and adjustment). 1000 rubles;
    • External cleaning indiscriminately. 300 rubles;
    • Adjustment. 300 rubles;
    • Bulkhead carburetor and engine. 2000 rubles;
    • Sealing the branch pipe. 200 rubles.

    Adjusting your carburetor regularly can improve the efficiency of your chainsaw and reduce fuel costs. At the same time, it is recommended to strictly follow the technology or entrust the work to specialists.

    Advantages and disadvantages

    Zama carburettors are very reliable and easy to operate. It is on the Stihl 180 Chainsaw that a carburetor is installed, on which there are no screws for adjusting the quality and quantity of the mixture, as we are used to. One screw greatly simplifies adjustment.

    The membrane carburetor has significant disadvantages. With such a carburetor, the chainsaw works in any position. With side cut, vertical, etc.

    Despite the aforementioned pros, the carburetor is sensitive to fuel quality. In addition to clean air from the air filter, the carburetor must be supplied with Cleaned fuel from the gas tank. But this is not always possible, so at least once every six months it must be cleaned and blown.

    Husqvarna Saw Carburetor Adjustment.

    For the running-in mode, so that the parts receive sufficient lubrication, the carburetor of the Husqvarna chainsaw is set in such a way that the maximum speed is 600-700 rpm. Below working. If it is not possible to set the operating maximum frequency by the tachometer, change the presettings with the screw H Do not. It is forbidden to exceed the value of the maximum number of revolutions by the manufacturer. If, after completing the adjustment, the saw chain moves when the engine is idling, turn the screw T counterclockwise to bring it to a complete stop.

    For accurate adjustment, the saw must be warmed up for at least 10 minutes, placed on a flat surface. The tire should point away from the person making the tune. At the initial stage, the highest idle frequency should be found. To do this, screw L is smoothly turned first from left to right, then vice versa. When the maximum revolutions are found empirically, it is necessary to Unscrew the screw L counterclockwise by a value from 1/8 to a quarter of a full revolution.

    Idling is adjusted by the nozzle marked with the letter T. It must be turned from left to right until the chain starts moving. Then push back smoothly until the chain does NOT stop rotating. The H screw is correctly installed if the noise of the saw at full throttle without load remains low. If the exhaust is too smoky and the saw makes a lot of noise, the mixture is too rich. The H jet must be turned clockwise until the correct sound is set. How to properly tune the carburetor can be seen below.

    How much does a new carburetor cost

    Chainsaws Stihl 180 are in great demand, primarily due to their reliability. The carburetor is no exception and is also quite reliable and unpretentious. Adjustment or repair of the carburetor is required only after long-term operation, and not less than after 5-7 years (with an average load). The tuning process itself is simplified as much as possible by Stihl engineers, this is the first chainsaw in which only one screw is provided for adjustment.

    How to properly adjust the carburetor with your own hands?

    After rinsing and completely cleaning the carburetor, assemble it and start adjusting. First of all, you should understand the purpose of the adjusting screws. The instruction will help with this, but some general points should be considered right away. The most common designations for screws are:

    • H. adjusts the state of the main jet, i.e. Adjusts the maximum rotation speed of the motor shaft;
    • L. adjusts the idle jets (responsible for the minimum shaft rotation speed)
    • T. regulates the engine idling. It can also be designated LA or S, on some carburetor models it is not at all.

    Turning screws H and L clockwise depletes the air-fuel mixture, and counterclockwise enriches it (the amount of gasoline increases). When the screw T rotates, the idling speed of the shaft changes. it increases clockwise, and decreases in the opposite direction.

    Figure 2. Carburetor adjustment mechanisms

    Before proceeding with direct actions, you should find and carefully study the information on the position of the adjusting screws (the magnitude of the angles of rotation during adjustment). This information is available in the instructions for the chainsaw. Then you need to prepare the workplace. lay the dust on a flat horizontal plane, direct the chain in the opposite direction from you. Detach all covers, remove foam rubber and air filter. At this preparatory operations are considered completed, you can proceed to the main part of the work.

    Carburetor adjustment procedure:

    • Smoothly tighten the screws H and L clockwise until they stop. Be careful not to break the screws. this will lead to the complete loss of the carburetor.
    • Unscrew both screws one and a half turn.
    • Run the engine for 10 minutes and warm it up. This is a necessary moment, since it will NOT be possible to correctly adjust the carburetor on a cold engine.
    • Turning the screws H and L, alternately adjust the rotation of the shaft at maximum and minimum speed.
    • Adjust the position of the screw T (or it may have another designation), the idle speed of the chainsaw is adjusted. It is necessary to achieve smooth and stable engine operation. Important Observe whether the chain is idling or not. If it moves, turn the screw a little more counterclockwise.

    You can check the operation of the engine visually and by ear. Too rich mixture will cause thick smoke from the exhaust. When the lean mixture is being fed, a whistling sound is heard while the saw is running. Excessive economy mode is harmful. if the L screw is set to “lean” fuel, there will be problems with starting the engine. If the H screw is set to lean, the saw will noticeably lose power. You can determine the correct setting by the following criteria:

    • At idle speed, the engine does NOT stall, and the chain is motionless;
    • When the engine is running, there is excessive smoke from the exhaust pipe;
    • The engine demonstrates good throttle response (picks up speed quickly when you press the accelerator).

    A detailed description of the setting is available in the instructions that come with the instrument in the delivery set. It should be carefully studied as there may be some features or specific requirements set by the manufacturer and related only to this saw model. If all requirements are met exactly, the performance of the chainsaw will be restored to its original state.

    Adjustment tools

    To tune the carburetor, you will need a Phillips or slotted screwdriver of different lengths or thicknesses, the size depending on the design of this unit and the features of the engine assembly. It should be noted that some manufacturers make Carburetors designed to use special tools.

    In particular, special types of screwdrivers may be required to tune Husqvarna carburettors worthy of imported tools. It is advisable to clarify this question even when buying a chainsaw, so that you can purchase the necessary additional equipment in advance.

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    In addition, you will need refined gasoline or acetone to flush and clean the device. They are used to clean the outer surfaces of the carburetor. All internal channels are washed with kerosene, diesel fuel or white spirit. Before flushing, the carburetor is disassembled, all rubber or plastic parts that may suffer from contact with aggressive chemical compounds are removed.

    Open-end or spanner wrenches are used to disassemble the carburetor. The internal channels are flushed in specially designated trays, sometimes plastic syringes are used for this.

    Design and working principle

    A carburetor is a device in which fuel (gasoline) and air are mixed in predetermined proportions, with the subsequent supply of the prepared mixture to the engine cylinder. Almost all models of chainsaws are equipped with Carburetors of the same type, so the device and principle of operation are the same.

    The main structural elements of the carburetor are:

    • The body is made of die-cast aluminum for light weight. Chainsaws constantly have to be moved from place to place, during operation they are held by hands, therefore, reducing the weight of the tool is the primary task of manufacturers;
    • Diffuser with air damper, which are located at the inlet;
    • Nozzles, which are valves for metering fuel;
    • Sprayer that injects gasoline into the chamber (in the diagrams it is designated as the main jet)
    • Fuel (Float) chamber.

    Figure 1. Diagram of a chainsaw carburetor

    The principle of the carburetor can be described as a cycle consisting of the following steps:

    • Air damper opens during engine start.
    • The piston stroke creates vacuum in the air channel, as a result of which air enters the diffuser, the amount of which is regulated by the position of the air damper.
    • Gasoline flows from the gas tank to the float (fuel) chamber. The rate of its admission is regulated by jets.
    • Gasoline and air are mixed in the diffuser, resulting in the formation of a fuel-air mixture, which then enters the engine cylinder. The more mixture enters the combustion chamber of the cylinder, the higher the power and speed on the engine shaft will be.

    How to properly adjust the carburetor on a chainsaw with your own hands?

    A chainsaw is a useful, and sometimes simply necessary tool for the owner of a private house. It has a high degree of autonomy, can be used in the field, where there is no possibility of connecting to the power supply network. For some craftsmen, the chainsaw is one of the main devices that perform large amounts of work almost daily. Such loads knock down the factory settings, which were installed for all fundamental engine components.

    The operating mode most often changes in the carburetor, which has to be adjusted again. Without understanding the design and principle of operation of this element, it is impossible to properly adjust it. The question concerns many users who closely operate chainsaws, so it will be useful to consider it more carefully.

    • Design and working principle
    • When is carburetor adjustment necessary?
    • Adjustment tools
    • How to properly adjust the carburetor with your own hands?
    • How to customize China-made dust?

    When is carburetor adjustment necessary?

    Initially, from the moment the instrument was sold, all Carburettors were adjusted and tuned at the factory. However, in the process of operation, the settings gradually go astray, and the operating mode changes in accordance with the operating conditions. Signs of a carburetor malfunction may include:

    • Too high consumption of gasoline, thick smoke comes from the exhaust pipe;
    • The engine power is clearly not enough to perform normal tasks;
    • Engine speed “floats”;
    • After starting, the motor stalls either immediately or after a few seconds
    • The engine cannot be started at all;
    • The chainsaw “shoots”, there are sharp claps in the tool engine.

    It should be noted that during the running-in of a new engine, the carburetor is set to a reduced fuel supply in order to limit the engine power. After the end of the run-in, the fuel supply increases to the nominal value. These adjustments are made using the adjusting screws on the carburetor body (usually two or three).

    How to customize China-made dust?

    The design of the carburetor on Chinese chainsaws is not fundamentally different. The order and principle of adjustment also do not differ and are performed in the same order. The only difficulty that may arise during work is determining the purpose of the adjusting screws. Typically the T screw is at the top and the H and L are at the bottom of the carburetor body. One additional screw may be present.

    Figure 3. Location of adjusting devices

    Usually their purpose is determined empirically, slightly changing the position and follow the result. After the purpose of the elements is clearly defined, further adjustment is not difficult and is carried out in the usual way.

    Chainsaw carburetor tuning is an important and necessary procedure that must be periodically performed to restore the normal operation of the tool. This process does NOT create fundamental complexity, but requires the user to be careful, attentive and follow safety rules. The chainsaw chain will usually NOT be removed as you will need to observe its position. Therefore, it is important to constantly remember about the possibility of launching it and take the necessary caution.

    The adjustment should be done smoothly, with small changes in the position of the screws, so as not to cause too sharp changes in the shaft rotation mode. The result depends on the care and thoroughness of the user, and a properly tuned carburetor will extend the life of the tool.

    So let’s get started!

    What do you need?

    • First, the instruction manual for the device itself.
    • Secondly, the tachometer. What exactly we need it for, we will consider a little later.
    • Third. a screwdriver.

    To get started, carefully familiarize yourself with the design of your saw. The first thing you need to do is determine where the carburetor jets are, and even more importantly, the adjusting screws. Usually, there should be two to three screws. One of them regulates idle speed, and the other two. low and high.

    It is them that you will need to regulate, either twist or unscrew in order to enrich or lean the fuel mixture.

    If you need a lean mixture, simply turn the regulator clockwise, if you enrich it, then accordingly.

    To adjust the idle speed, the screw, which is responsible for this, also needs to be either turned clockwise in order to increase the speed, or, as you may have guessed, in the opposite direction to decrease them.

    But I want to warn you, be careful when adjusting the carburetor. After both leaning and enriching the fuel mixture, as well as playing with the revs, it has very serious consequences.

    Now let’s take a look at the features of adjustment on different models, both more modern and domestic, and more familiar to us.

    When You May Need Adjustment

    With proper operation, a good Stihl 180 chainsaw (or any other) should serve you well for a long time. But everything happens.

    The most common reasons are:

    • Loose fixing screws
    • The engine is worn out (in this case, adjusting this chainsaw, like GoodLuck, or Sturm will only help for a while, ideally it is better to immediately carry it for repair)
    • The carburetor is clogged (in this case, it will also have to be cleaned).

    Step by step setup

    “Partner 350” is regulated similarly to many models of chainsaws.

    In this model, we have three regulators:

    • Low rpm. L
    • High. H
    • Singles. T.

    Once released from production, these chainsaws are tuned to deliver more mix than necessary. This should be the case only in the first hours of work.

    When the motor warms up, it is best to re-tune it. At idle, turn the screw T counterclockwise until the chain stops, after which we adjust each of them in the order: L, H, T.

    Screw L must be returned counterclockwise ¼ turn at the moment when the largest turns begin at idle.

    Adjust the screw H as follows: warm up the convertible and turn it counterclockwise ¼ turn. To determine if everything is in order you will need a tachometer. Turns must be the same as indicated in the maximum in the passport of the chainsaw.

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

    The Husqvarna carburetor is adjusted in the same way.

    Partner 351 differs only in that its factory settings initially supply the optimal amount of mixture, that is, everything should work correctly at once. But, if necessary, the instructions above will help you set up the carburetor correctly.

    Ural adjustment

    It differs slightly in that it should not be carried out in sharp maximum revolutions, but Make sure that the chain picks them up quickly, but smoothly, without moving along the bus.

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

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

    The best info on adjusting carburetors on a chainsaw

    Greetings to you dear and most loyal readers of my blog. In today’s article, I decided to consider how to adjust the carburetor on a chainsaw. After all, as it seems to me, you have repeatedly encountered a problem that your “darling” let you down when it was so necessary. And since you and I are Economical and do not want to spend money on what we can do ourselves, then let’s learn how to adjust the carburetor on our chainsaws with our own hands, without involving professional repairmen. And as you will see shortly, this is very easy to do. You don’t even need anything special to do. I specifically considered the adjustment of carburetors of all famous brands of dust, each of which has its own tricks and nuances, and in my opinion this is the best information on the network!

    For a snack

    Good luck and see you soon! Andrey Noak was with you.