Chainsaw adjustment Husqvarna 135 carburetor

Chainsaw Husqvarna (Husqvarna) 137. carburetor adjustment.

The best advice that I can give you is to contact the specialists! Believe me, for very little money, specialists will adjust the carburetor, check the general condition of the saw. But if you still need to adjust the carburetor on the Husqvarna 137 saw yourself, then I will try to describe this process in detail. Also at the end of the post I added a video on how to adjust the carburetor of a chainsaw at idle.

detailed instructions for adjusting the chainsaw carburetor here: How to adjust the chainsaw carburetor step by step!

Adjusting and adjusting the carburetor Husqvarna 137

husqvarna137 carburetor adjustment

In the picture above, you can see three adjustment screws. Each of them has its own purpose:
The T screw is required to adjust the idle speed.
Screw L serves to adjust low rpm.
Screw H adjusts high rpm.

Husqvarna chain saw carb adjustment

Adjustment procedure:
First, with the L screw (rotating it), we are looking for the highest idle speed. After we have found them, it is necessary to turn this screw a quarter of a turn against the clock hand. If in this position the chain continues to rotate, then by rotating the screw T we achieve its stop.
Then we warm up the engine at full speed in the region of 10-15 seconds and turn the screw H a quarter counterclockwise. We wait 10 seconds and listen. the engine should work as a 4-stroke in sound. If a screeching sound is heard, then the mixture is poor (unscrew the screw), if it smokes, the enriched mixture (tighten the screw).

After adjusting the low and high speeds, we set the idle speed with screw T. This is done as follows:
1.The engine must be running
2.Rotate the screw T clockwise until the chain starts to rotate.
3.Rotate the screw in the other direction until the chain stops.

With a properly adjusted carburetor, your chainsaw quickly picks up speed and sounds like a 4-stroke engine.

Remember that a tachometer and experience are required to properly adjust the carburetor of your chainsaw. Therefore, it is better to contact a specialized service.!

Video about adjusting the chainsaw at idle speed:

Another video about Husqvarna carburetor repair in English.

What is the factory setting of a Husqvarna chainsaw carburetor?

In order for the saw to start anyway, even if the setting is incorrect, the factory settings of the screws H and L are applied. Most Husqvarna chainsaws can be started by unscrewing both screws exactly one and a half turns. Only then can the position of the screws be changed in order to achieve the desired fuel consumption and maximum efficiency. It is regulated by XX also after these manipulations.

If you still have questions about adjusting the carburetor on the Husqvarna 137 chainsaw and other models of this line, I recommend watching this

Adjusting the carburetor of a Husqvarna chainsaw

Like all other saws, the husqvarna has the same carburetor adjustment algorithm. Therefore, the instructions will be relevant for other tools and models of chainsaws such as Husqvarna 142.236.

Before starting work, make sure that the air filter is clean and that all other components are working properly. The fuel supply to the float chamber should work without interruptions, and the ignition system is configured correctly and has a fresh spark plug.

  • Set the carburetor to factory settings. This must be done with the engine stopped.
  • Now you can start the engine and be sure to warm it up for a few minutes. Adjustment of the XX carburetor of the Husqvarna 137 is carried out only on a warm engine.
  • Turning screw L clockwise, you need to set the highest speed of the crankshaft, then turn it back a quarter of a turn. Adjust the speed of the crankshaft with the screw T so that the chain does not rotate. It should not be set in motion without pressing the accelerator.
  • Now you need to set the maximum speed and their power. It is enough to connect the tachometer to the ignition system and set the maximum possible speed using the accelerator. Compare them with your passport data. If they differ, then unscrew or tighten screw H. By changing the range, you can create restrictions to make the saw work efficient and save the motor resource.

Fuel mixture preparation

When operating a chainsaw, a fuel mixture of gasoline and oil in a ratio of 15: 1 by volume should be used, that is, 1 liter of oil should be added to 15 liters of gasoline and the mixture should be thoroughly mixed. The amount of gasoline and oil in the fuel mixture is shown in this table:

ATTENTION! Application of oils: Lukony-2T; TNK-2T OIL: AZMOL Sport 2T GD ”and others, and used oil in the fuel mixture will lead to failure of the needle bearing of the connecting rod.

How to adjust the carburetor on a Husqvarna 137 chainsaw

The chainsaw is a great helper for any man living in his home. The chainsaw device is a complex system that requires careful maintenance and requires increased attention. Today you will learn how to adjust the carburetor of a Husqvarna 137 chainsaw with your own hands in the garage.?

What you should pay attention to?

Once your Husqvarna carburetor adjustment is complete, you need to make sure the engine is running smoothly and the saw can easily rev up and down. The idling of the chain is considered abnormal, so it is necessary to re-adjust its connection to the clutch with the screw H.

Do not forget that the assembly is not immediately set up: you need to wait a while, as the Husqvarna chainsaw does not immediately respond to changes in the position of the screws. This time can range from 5 to 15 seconds. This time does not prescribe the table, so you can only find out experimentally.

If, after adjustment, a huge amount of smoke appears during operation, then you need to adjust the supply of the fuel and oil mixture. For these purposes, rotate the screw L.

Do-it-yourself Husqvarna carburetor adjustments?

In order to correctly adjust the carburetor of the chainsaw, you need to stock up on the appropriate tool in advance.

You will need the following list:

  • The most common screwdriver, with which you can unscrew or tighten the adjusting screws;
  • A tachometer designed to count the revolutions of the crankshaft. It is necessary when adjusting the idle speed, since it is quite problematic to determine the number of revolutions per minute by ear;
  • Phillips screwdriver. It is needed to be able to unscrew the screw (T);
  • Compressor with a special gun connected to them. The blowing device will help get rid of excess debris and dirt, since the carburetor must always be clean.
chainsaw, adjustment, husqvarna, carburetor

Many Husqvarna chainsaws use a special section adjusting bolt. See in advance which ones you have installed and purchase the appropriate kit. This will help to avoid many difficulties at the initial stage.

When carburetor adjustment is necessary?

The reasons why it will be necessary to adjust this unit can be listed for a very long time.

Among the main malfunctions are the following:

  • Increase in idle speed;
  • The appearance of a large amount of smoke during operation;
  • Deterioration of starting properties;
  • Insufficient tool power when cutting.

This is not a complete list of all known faults. Sometimes a procedure such as adjusting the carburetor on a Husqvarna chainsaw may need to be done after a major overhaul of the power plant or after maintenance.

The developers of the Husqvarna 137 write in the passport that the carburetor adjustment must be carried out before and after running in the tool.

chainsaw, adjustment, husqvarna, carburetor

How the carburetor works on a Husqvarna 137 chainsaw?

On chainsaws of these models, the Walbro carburetor is most often installed from the factory. Before adjusting the Walbro carburetor on a Husqvarna chainsaw, you need to have a minimum understanding of its structure and know how it works.

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Situations in which adjustment is necessary

New chainsaws are supplied from the manufacturer with pre-adjusted carburetors. This is called standard adjustment. But for the normal passage of the process, it is required to lower the maximum engine speed, adjust the carburetor. After running in, the chainsaw needs fine tuning to achieve maximum engine efficiency.

Also, a signal for cleaning and adjustment is an increased fuel consumption, which negatively affects the operation of the exhaust system. Simply put, the chainsaw begins to smoke heavily and the muffler becomes clogged with carbon deposits, which in turn will lead to a decrease in power. With a lack of fuel in the mixture, engine parts are poorly lubricated and premature wear occurs. Also, a poor-quality mixture can cause the engine to jam due to overheating (this is one of the reasons why).

Adjustment is necessary when the engine does not idle, stalls or does not develop full power.

carburetor adjustment must be done with clean air and fuel filters.

  • HOW TO CORRECTLY ADJUST the carburetor on a Husqvarna 135 chainsaw.
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  • HOW TO SET UP a carburetor on a Stihl chainsaw. How to properly adjust the chainsaw carburetor
  • Situations in which adjustment is necessary
  • Tools
  • How the carburetor is adjusted
  • Process description
  • Adjusting the carburetor of a Chinese chainsaw
  • Video How to adjust the chainsaw carburetor. Service
  • HOW TO SET UP THE CARBURETOR ON A CHAMPION CHAINSAW. Husqvarna Saw Carburetor Adjustment.

Adjusting the carburetor of a Chinese chainsaw

Carburettors installed on Chinese-made saws are made similarly to European ones and have the same adjustment screws.

The carburetor of a Chinese chainsaw is adjusted according to the algorithm presented above, and differs in that when initially adjusting the screws (L) and (H), they must be turned out two turns. Further, the carburetors of the Chinese saw are adjusted in the same way as the European ones.

The setting of the saw carburetor can be studied in the video below. In this video, the wizard shows how a step-by-step adjustment of a Chinese-made chainsaw is performed without using a tachometer. Carries out after adjustment check in various modes.

Adjusting the carburetor of a chainsaw, although it looks like a fairly simple process, requires a very careful and responsible approach. The article describes the process in sufficient detail, but if you have never adjusted a chainsaw, you should contact a specialist, this will help save time, nerves and money.

Process description

If the carburetor of the chainsaw is not adjusted and it is not possible to start the chainsaw, then the adjustment starts by setting the screws (L) and (H) to the standard setting. This is 1/5 turn of the screws until they are fully tightened. After that, you need to start the engine, let it run a little and warm up. The next step is to set up the low speed mode. Optimum low engine performance can be achieved by adjusting the screw (L) and idle speed (T). To do this, first the screw (L) is tightened until the maximum engine speed is obtained, then it is released by 1/4, and the idle speed is normalized with the screw (T).

After adjusting the work on the “bottom”, the thrust and maximum engine speed are adjusted. To do this, slowly tighten the screw (H) and check the speed according to the readings of the electronic tachometer.

exceeding the maximum engine speed declared by the manufacturer is unacceptable.

An important step is to check the saw in all operating modes after adjusting it, for this you need to let the chainsaw cool down, and then start it according to the cold tool start algorithm. If the saw starts up normally and idles smoothly, you need to check how it cuts. If in the process of checking deficiencies in the power of the chainsaw are found, then it is necessary to repeat the adjustment of the screw (H) by unscrewing it and checking the thrust in operation.

loss of thrust at maximum rpm recommended by the manufacturer is an indicator of CPG wear or poor fuel quality.

HOW TO CORRECTLY ADJUST the carburetor on a Husqvarna 135 chainsaw.

Adjusting the carburetor Husqvarna 372 XP, 365

Adjusting the carburetor of a Husqvarna 372 XP chainsaw means adapting the engine to local conditions such as climate, altitude, gasoline quality and oil type for two-stroke engines.

The carburetor has three control options:

L = low speed jet H = high speed jet T = Idle speed adjustment screw.

Likers L and H adjust the amount of fuel that matches the air flow supplied by the throttle valve.

If the nozzles are screwed in clockwise, the mixture will be poor (less fuel in relation to the amount of air), and when the nozzles are unscrewed, it will be richer.

A bad mixture gives higher speeds, and a richer mixture gives lower speeds. The T screw adjusts the idle position of the throttle.

If the T screw is turned clockwise, the number of turns. and if you turn the arrows, the number of revolutions will decrease.

Presetting and starting your Husqvarna 365 XP chainsaw

The carburettor has been pre-adjusted during the performance check at the factory. Pre-adjustment: H = 1 turn, respectively L = 1 turn.

To ensure that the parts of the Husqvarna saw engine are sufficiently lubricated (pumped in), the carburetor is set with a slightly higher fuel mixture for the first 3-4 hours of operation.

For such an installation, the maximum speed is set at 6-700 rpm below the recommended speed.

If it is impossible to check the maximum number of revolutions using a tachometer, then the H jet should not be set on the preset.

Do not exceed the maximum number of revolutions. If the chain rotates at idle speed, turn the screw T counterclockwise to stop it completely.

Tools

Correct adjustment of the chainsaw carburetor should be carried out using a special tool. a tachometer. It allows you to most accurately determine the maximum number of engine revolutions and adjust them according to the manufacturer’s requirements. A small slotted screwdriver is required for adjustment. For some models of chainsaws, you will need a special adjusting key, without which work cannot be carried out.

The key for adjusting some models of carburetors is available only in service centers authorized for the repair of chainsaws by the manufacturer. This measure is aimed at reducing breakdowns due to incorrect settings by inexperienced users and those who are engaged in repairs without official permission to do so.

Setting up the chainsaw, if possible, should be carried out in official service centers that have a certificate from the manufacturer.

HOW TO SET UP a chainsaw carburetor. Chainsaw carburetor device

To independently adjust the carburetor of a chainsaw, you do not need to be a professional motor technician. However, you still have to memorize some aspects of the carburetor’s operation regarding the process of preparing the fuel mixture.

The vast majority of chainsaws are equipped with Chinese-made Walbro carburetors. In their structure, they are simple, if not primitive. There is a monoblock body of the straight-through type with a through hole. A diffuser is located inside the hole. a narrowing of the passage with the fuel injection channel. There are dampers on both sides: the smaller one is the throttle one, it regulates the amount of the fuel mixture to be fed into the cylinder. A larger damper. air, serves to limit the air flow during a cold start.

Walbro carburetor device: 1. fuel inlet fitting; 2. impulse channel of the membrane pump; 3. inlet valve; 4. membrane of the fuel pump; 5. exhaust valve; 6. filter mesh; 7. air damper; 8. throttle valve; 9. fuel channel; 10. idle speed adjustment screw; 11. needle; 12. idle nozzles; 13. control membrane; 14. fuel chamber; 15. main jet; 16. diffuser; 17. the main adjusting screw

All the magic of fuel preparation takes place in the covert channels and the diaphragm pump chamber. When the throttle valve is turned, the cross section of the channel through which fuel is injected into the mixing chamber increases slightly and the fuel enters in a larger volume. In this case, the carburetor has two kind of valves: for feeding at low and high speeds. When changing the position of the throttle valve, the fuel flow changes proportionally between the two valves.

The need for such a device is that the quality of the mixture should be different at idle and under load. At the same time, the channel through which the fuel is supplied to the mixer at idle speed does not completely overlap when the engine accelerates and vice versa. the maximum speed channel is slightly undercut at idle speed.

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Adjusting the carburetor of a Chinese chainsaw

Carburettors installed on Chinese-made saws are made similarly to European ones and have the same adjustment screws.

The carburetor of a Chinese chainsaw is adjusted according to the algorithm presented above, and differs in that when initially adjusting the screws (L) and (H), they must be turned out two turns. Further, the carburetors of the Chinese saw are adjusted in the same way as the European ones.

The setting of the saw carburetor can be studied in the video below. In this video, the wizard shows how a step-by-step adjustment of a Chinese-made chainsaw is performed without using a tachometer. Carries out after adjustment check in various modes.

Adjusting the carburetor of a chainsaw, although it looks like a fairly simple process, requires a very careful and responsible approach. The article describes the process in sufficient detail, but if you have never adjusted a chainsaw, you should contact a specialist, this will help save time, nerves and money.

Algorithm and description of setting the carburetor Husqvarna

Husqvarna carburetor, adjustable in the same way as carburetor settings on other brands of chainsaws.

Immediately before adjusting, it is necessary to carry out a complete diagnosis of the saw and make sure that there is no difficulty in supplying fuel and air leaks into the crankcase of the chainsaw. It is also necessary to make sure that the air filter is clean and, if necessary, replace it with a new one.

The order of work is as follows:

  • Saw muffled with Husqvarna carburetor factory setting.
  • The engine starts and the saw warms up for a few minutes.
  • By turning the screw (L) clockwise, the position is found at which the engine develops maximum speed, after which the screw must be unscrewed 1⁄4 back. If at the same time the chain of the chainsaw rotates, then it is necessary to reduce the idle speed by adjusting the position of the screw (T).
  • The next stage is adjusting the power of Husqvarna at maximum speed and adjusting their number. To do this, the tachometer is connected to a running chainsaw, the throttle knob is squeezed out to full, after which the tachometer readings are checked. If the value of the maximum speed differs from the maximum number recommended by the manufacturer, then by changing the position of the screw (H), the tachometer readings are returned to normal.

Ignition adjustment after carburetor adjustment

If cleaning and adjusting the carburetor did not correct the existing problem, you need to check the spark plug and tune the engine. It is worth acting in the following order:

  • The candle is unscrewed and a visual inspection is carried out. If it is dry with light brown carbon deposits, it can be considered intact.
  • If traces of gasoline are found on the spark plug, readjust the carburetor. This is because it supplies an excess amount of fuel to the internal combustion engine, filling it.
  • If the candle looks normal, check the electrical equipment. First of all, the cable that supplies current to the candle. The end of it is brought a short distance to the radiator grille of the cylinder and the starter is turned with a cord. A spark should slip through. If not, the cable is checked with a tester and, if necessary, replaced.
  • If the cable is in good condition, the ignition coil is tested. If the inspection does not reveal singed or broken wires, the coil is called with a tester, comparing the data with the accompanying documentation. If deviations are found, the block must be replaced with a similar one.

After replacing the coil unit, the magneto gap should be set. The gap between the ignition coil and the flywheel should be between 0.2 and 0.4 mm. To set the gap, you need a set of probes or you can use foil of a suitable thickness. The probe is clamped between the coil and the flywheel at the time of installation, and then pulled out.

When adjustment is needed

The need to adjust the carburetor of a chainsaw is rare. often there are problems with the flow of fuel, air or wear of parts. But sometimes adjustment is still required:

  • a running engine stalls after a few seconds, or it does not start. the reason for this is a too rich mixture;
  • excessive exhaust, high revs, increased consumption. in this case, on the contrary, the mixture is too lean, that is, there is not enough air;
  • RPM is kept at the same level after its decrease or increase by the operator. the cause may be a stuck needle valve.

The factors leading to such changes can be the following:

  • Severe vibration damages the protective cover and the adjusting jets are unscrewed, changing the setting. In this case, it is possible to adjust the carburetor on the chainsaw.
  • Wear of elements of the piston system. Adjusting the carburetor in this situation can be of temporary help. Replacement of worn-out components is recommended.
  • Poor quality fuel, faulty filter, or long storage can cause blockages. In this situation, the carburetor must be removed, rinsed with a special liquid or clean gasoline, assembled and re-adjusted.

It is best to start tuning the saw by checking the jets, fuel and air supply. After that, proceed to dismantle the carburetor, and then. to check the piston system.

When does the carburetor of a Husqvarna chainsaw need adjustment?

There are a lot of problems that can be solved by adjusting the carburetor. Adjusting the carburetor of a Husqvarna chainsaw is necessary when such malfunctions appear:

  • increased idle speed;
  • strong smoke during tool operation;
  • Difficulty starting a cold or hot engine;
  • lack of traction and reduced maximum revs.

This is by no means a complete list of problems that can be solved by tuning the Husqvarna carburetor. In some cases, the quality and quantity of the fuel mixture is adjusted after an overhaul of the engine or in the process of scheduled maintenance of the chainsaw.

Husqvarna AB recommends adjusting the carburetor before and after running in.

Situations in which adjustment is necessary

New chainsaws are supplied from the manufacturer with pre-adjusted carburetors. This is called standard adjustment. But for the normal passage of the process, it is required to lower the maximum engine speed, adjust the carburetor. After running in, the chainsaw needs fine tuning to achieve maximum engine efficiency.

Also, a signal for cleaning and adjustment is an increased fuel consumption, which negatively affects the operation of the exhaust system. Simply put, the chainsaw begins to smoke heavily and the muffler becomes clogged with carbon deposits, which in turn will lead to a decrease in power. With a lack of fuel in the mixture, engine parts are poorly lubricated and premature wear occurs. Also, a poor-quality mixture can cause the engine to jam due to overheating (this is one of the reasons why).

Adjustment is necessary when the engine does not idle, stalls or does not develop full power.

How To Adjust / Tune a Chainsaw Carburetor | Husqvarna Stihl BEST Way

carburetor adjustment must be done with clean air and fuel filters.

How to remove the carburetor and whether to do it before tuning

In the event that the chainsaw does not develop speed or, on the contrary, works at excessively high, the carburetor can be adjusted without removing.

But if the chainsaw does not start, the rpm freezes at the same level or it is unstable. Chainsaw carburetor tuning will not change the situation. It must be removed to clean or replace parts. In this case, it is necessary to act in the following order:

  • Having unscrewed the retaining fasteners, remove the upper saw casing.
  • We remove the gasket and part of the air filter by unscrewing the bolts or snapping off the fasteners.
  • There is a fuel hose on the right side of the carburetor. We remove it together with the air damper control rod.
  • Remove the carburetor from the mounts that hold it.

Disassembly of the carburetor is carried out in accordance with the instructions supplied with the kit. When disassembling, be very careful when folding the parts onto the prepared fabric. Due to the small size, there is a risk of losing components during disassembly and flushing.

All parts obtained in this way are washed in a special liquid, dried and wiped with a lint-free cloth.

Channels, tubes and nozzles are blown out with compressed air, if possible, after rinsing them in an ultrasonic bath.

DIY carburetor repair

If in the process of carrying out a full diagnosis of the Husqvarna chainsaw, carburetor defects were found, then some of them can be repaired without contacting a Husqvarna AB service center. For example, you can independently:

  • change the gaskets under the covers of the main chamber and the fuel pump;
  • clean or replace the strainer;
  • replace the diaphragm or needle valve of the main chamber;
  • troubleshoot the fuel pump diaphragm.
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Gaskets, diaphragms and a rocker needle valve can be found in the repair kit provided for each Husqvarna chainsaw carburetor model.

Also, if you have some experience, you can try to restore a faulty injector valve, but you cannot guarantee a positive result when trying to restore an injector, if it is faulty, manufacturers recommend changing the carburetor completely.

The first thing to do before removing the carburetor from Husqvarna is to clean the saw with a compressor, since dirt can interfere with a quality repair. Next, you need to open the top cover of the chainsaw, remove the air filter, disconnect the rods from the air and throttle control levers. After that, unscrew the screws securing the carburetor.

It is quite easy to disassemble the carburetor body for repair. The main chamber cover is held in place by four screws, which can be removed with a regular screw, the fuel pump cover is secured with one wide screw.

Below is a video that will make it clear how exactly you can repair the carburetor without contacting a Husqvarna service center.

Adjusting and adjusting the carburetor Husqvarna 137

husqvarna137 carburetor adjustment

In the picture above, you can see three adjustment screws. Each of them has its own purpose:

The T screw is required to adjust the idle speed.

Screw L serves to adjust low rpm.

Screw H adjusts high rpm.

Adjustment procedure:

First, with the L screw (rotating it), we are looking for the highest idle speed. After we have found them, it is necessary to turn this screw a quarter of a turn against the clock hand. If in this position the chain continues to rotate, then by rotating the screw T we achieve its stop.

Then we warm up the engine at full speed in the region of 10-15 seconds and turn the screw H a quarter counterclockwise. We wait 10 seconds and listen. the engine should work as a 4-stroke in sound. If a screeching sound is heard, then the mixture is poor (unscrew the screw), if the enriched mixture smokes (tighten the screw).

After adjusting the low and high speeds, we set the idle speed with screw T. This is done as follows:

1.The engine must be running

2.Rotate the screw T clockwise until the chain starts to rotate.

3.Rotate the screw in the other direction until the chain stops.

With a properly adjusted carburetor, your chainsaw quickly picks up speed and sounds like a 4-stroke engine.

Remember that a tachometer and experience are required to properly adjust the carburetor of your chainsaw. Therefore, it is better to contact a specialized service.!

Adjusting the carburetor on a Husqvarna chainsaw

Chainsaw Husqvarna (Husqvarna) 137. carburetor adjustment.

The best advice that I can give you is to contact the specialists! Believe me, for very little money, specialists will adjust the carburetor, check the general condition of the saw. But if you still need to adjust the carburetor on the Husqvarna 137 saw yourself, then I will try to describe this process in detail. Also at the end of the post I added a video on how to adjust the carburetor of a chainsaw at idle.

Do-it-yourself carburetor adjustment on a chainsaw

Chainsaw carburetor adjustment ensures efficient operation of the tool at full power while saving fuel. Adjustments must be made with a clean fuel and air filter. For a larger number of carburetors, the adjustment is carried out with three screws: for maximum and minimum revolutions and idle speed adjustment.

The H and L screws adjust the ratio of the mixture of gasoline and air, which is determined by opening the throttle valve of the carburetor. When the screws are unscrewed, the mixture is enriched, and the revolutions fall accordingly, when the screws are tightened, the mixture becomes leaner. the revolutions grow.

The designation H refers to the maximum speed screw that controls the main jet, L. to the minimum speed screw that controls the idle jet. The S screw is used to fine-tune the idle speed. Sometimes, to simplify tuning, the number of available carburetor adjusting screws is reduced.

Chainsaw carburetor tuning is divided into two stages. basic (factory settings), carried out with the engine off. and the final, produced on a running warm engine. The exact value of the angles of rotation should be taken from the operating instructions for the particular chainsaw. Failure to follow the manufacturer’s instructions may result in engine damage.

Basic carburetor adjustment.

chainsaw, adjustment, husqvarna, carburetor

The adjusting screws for maximum H and minimum L turns are slowly turned clockwise until they stop, then turned back 2 turns, other settings are also possible

Checking and adjusting idle speed.

We find the highest idle speed, for this we slowly turn the screw L in different directions. After finding the position of the highest engine speed, turn the screw L 1/4 turn counterclockwise. If the chain rotates at idle speed, screw T or (S) should be turned clockwise until it stops.

Checking and adjusting the maximum speed.

The maximum number of revolutions is changed by screw H. When screwing it in (clockwise rotation), the revolutions increase when it is turned out. decrease. Chainsaw engines have the highest rotation speed of 11500 rpm. up to 15,000 rpm. A higher speed does not provide ignition, moreover, it becomes dangerous for the engine. The rpm limit can be determined from the ignition interruptions. If they come, turn the screw H slightly counterclockwise.

If the engine is not checked for acceleration and maximum speed, then the adjustment of the chainsaw cannot be considered complete.

When the throttle trigger is smoothly pressed, the engine should confidently and quickly gain speed from idle to maximum (from 2800 rev. To 11500-15000 rev. Depending on the unit). If revolutions are gained slowly, with a lag, screw L must be slowly unscrewed counterclockwise, but no more than 1/8 of a turn.

After adjusting the acceleration and maximum speed, the saw should be checked again at idle speed. the engine must run steadily and the chain must not move. Chainsaw tuning should be repeated if this condition is not met but with the exception of the basic adjustment step.

Chainsaw carburetor adjustment

Most chainsaw carburetors have three adjustment screws:

  • L. jet screw for adjusting low speed
  • H. jet screw for high speed adjustment
  • Screw. T at Partner and Husqvarna (at Calm LA). adjusting the idle speed of the chainsaw

The H and L screws adjust the ratio of the mixture of gasoline and air, which is determined by opening the throttle valve of the carburetor. When the screws are unscrewed, the mixture is enriched, and the revolutions increase accordingly, when the screws are tightened, the mixture becomes leaner. the revolutions fall.

The screw T (LA) is designed to adjust the idle speed. The basic setting of the chainsaw is made at the factory during the final test. The carburetor is usually adjusted for a richer (than optimal) fuel mixture. The factory setting must be maintained during the first hours of saw operation. Then (optional) a more precise carburetor adjustment is made.

We begin the adjustment by setting the idle speed, for this we rotate the screw T (LA) counterclockwise, achieving a complete stop of the chain at stable engine speeds.

For further fine adjustment, you need a tachometer and it is better to entrust it to specialists. especially since in most cases it may not be needed.

We start setting up the tool with screw L, then use screw H and finally screw T (LA).

We find the highest idle speed, for this we slowly turn the screw L in different directions. After finding the position of the highest engine speed, turn the screw L 1/4 turn counterclockwise. If the chain rotates at idle speed, the screw T should be turned clockwise until it stops.

The H screw adjusts the power and speed. Adjusting the carburetor to a lean mixture leads to excessive speed, engine overheating and failure of the piston chainsaw.

We warm up the chainsaw engine at idle speed for at least 10 seconds and turn the screw H 1/4 turn counterclockwise. Let the engine run for about 10 seconds. then we check the maximum engine speed with a tachometer. If the maximum speed does not correspond to the passport one, the operation should be repeated. When the mixture is too rich, the muffler starts to smoke, when the saw is too lean, it squeals and overheats.

We finish the adjustment by adjusting the idle speed, as already described above. The idle speed is set correctly if the engine runs smoothly at minimum speed and the chain does not rotate.

The carburetor can be considered adjusted if the engine accelerates quickly and sounds like a four-stroke at full throttle.