How to adjust the idle speed of a Husqvarna chainsaw

How to adjust idle speed on a Husqvarna chainsaw

The chainsaw is an indispensable tool for people living in private households. It is a mechanism consisting of carefully fitted parts and assemblies.

Like any mechanism, it requires periodic maintenance and adjustment. Especially because of poor quality fuel. Consider the principles and procedure for adjusting the carburetor of a Husqvarna chainsaw.

What tool is required

First of all, you need to prepare a tool for adjusting the chainsaw carburetor. You will need a set of screwdrivers and open-end wrenches, a special cleaning compound that dissolves carbon deposits and debris.

Disassembly is best done on a table or workbench. On a part of the table, lay a flap of clean, preferably light and monochromatic fabric, on which the parts to be removed and a container for washing will be laid out. It is optimal if it is an ultrasonic bath.

How to properly adjust the carburetor on a Husqvarna chainsaw

How to tune the carburetor on a chainsaw Husqvarna Adjusting the carburetor on a chainsaw using three THL screws.

Check not idle speed adjustment.

Finding the highest turnover idle move, for this purpose, 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 for all this, the screw T on the other (S) should be turned clockwise until the oil stops.

Checking not 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 fifteen thousand rpm. The process of fine tuning Husqvarna on the idle chain saw is carefully described. A slightly increased speed is not provided by ignition, as oil becomes dangerous for the engine today. Limit turns are determined by misfiring. If they come, turn the screw H slightly counterclockwise.

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

With a smooth press on the gas trigger, the engine should confidently not quickly gain speed from idle to maximum (from two thousand eight hundred arr. To 11500-15000 arr. Based on the unit). If the revolutions are gained slowly, with a lag, screw L must be slowly unscrewed counterclockwise, but less than 1/8 of a turn.

Modern chainsaws have a complex system and consist of several main units that periodically require maintenance and adjustment. In this article, we’ll talk about how to adjust the carburetor on a Husqvarna chainsaw.

Adjusting and tuning the carburetor Husqvarna 137

In the picture above, you see three adjustment screws. They have their own mastery purpose:

The T screw is required to adjust the idle speed.

Screw L serves to adjust low rpm.

First, with the L screw (rotating it), we look for the highest idle speed. When we have found them, it is necessary to turn the myth screw a quarter of a turn against the clock hand. If the chain continues to rotate in this position, 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, do not turn the screw H a quarter counterclockwise. We are waiting for ten seconds without listening. 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 low, not high revolutions, we set the idle speed with screw T. This is done in this way:

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

The device and principle of operation of the carburetor

The carburetor is used to prepare a combustible mixture in a ratio determined by the operator from gasoline and air.

An excessively rich, as well as an excessively lean mixture will lead to unstable engine operation, can cause overheating and accelerate the wear of the piston system.

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The correct functioning of the device depends on the correct setting and adjustment.

How To Actually Tune A Chainsaw!

And for this you need to know the principles of the Husqvarna chainsaw carburetor.

Its design consists of the following elements:

  • body with clamping bolts and a set of gaskets;
  • fuel pump. a device that pumps a gasoline-oil mixture into the carburetor;
  • diaphragm. designed to limit the supply of a combustible mixture to the engine;
  • float chamber. fuel is collected in it, the level is regulated by the float, as necessary, the mixture is fed into the main chamber for mixing with air;
  • the main chamber. air passes through it, and fuel is injected there, the amount of the mixture supplied to the engine is regulated by the throttle valve located here;
  • diffuser. section of narrowing of the air supply tube at the place of fuel injection;
  • needle valve. a device that regulates the fuel supply;
  • jet. screws that regulate the supply of the mixture at high and low speeds, as well as an idle screw.

Also in the carburetor device, in addition to the throttle, there is a damper located at the inlet from the air filter. It artificially reduces the air supply, making the mixture richer for easier cold starting.

The injector valve is responsible for fuel injection into the main chamber, it also prevents air from entering. When adjusting the carburetor on a Husqvarna chainsaw, special attention should be paid to this valve, since its condition has a direct impact on engine performance. Long-term storage may cause the nozzle to stick. This will restrict fuel flow and prevent the engine from starting.

Also, from prolonged use or due to a factory defect, the valve can let air into the main chamber. In this case, only replacing it will help fix the problem.

The carburetor works as follows: the air flow entering the diffuser is mixed with the injected fuel, the resulting mixture is fed into the engine. The amount of the mixture is regulated by the throttle valve. The more mixture, the higher the engine speed.

Factory settings

The factory default setting for the Husqvarna carburetor is the position of the screws (H) and (L), in which a working chain saw is guaranteed to start. For Husqvarna tools, this is one and a half turns from fully tightened screws (H) and (L). In the process of adjustment, you must first set the screws to the standard position, then start the chainsaw and make precise adjustments to the power, the number of maximum revolutions and idle speed.

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

With a properly adjusted carburetor, your chainsaw develops quickly and does not sound the same as the operation of a 4-stroke engine.

Remember that a tachometer is not necessary to properly adjust the carburetor of a chainsaw. Therefore, it is better to contact a specialized service.!

Find out how the idle speed adjustment of the chainsaw goes

Chainsaw idle adjustments help reduce fuel consumption and wear when you are not using your chain saw. Typically, this is about 25-30% of the operating time of the chain saw with the engine running.

In this article we will show you how to adjust the idle speed for all popular models of gasoline saws, for example, Partner 350, Husqvarna, STIHL, etc.

If you have a Husqvarna chainsaw, idle adjustment. necessary step. Step by step instructions

Immediately, we note that all manufacturers on the chainsaw set the optimal adjustments. both for idle and for work under load. Therefore, the main task of the user is to return to the original factory settings. As an example, we took a Husqvarna chainsaw; idle speed adjustment is performed according to the following algorithm:

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

  • The engine warms up for sure. To do this, run the engine idling for about 10-15 minutes. If you adjust the operation of the chainsaw at a temperature of 5-10 degrees Celsius, then this interval should be increased to 20-25 minutes.
  • The L screw (it is he who is responsible for idling) turns to the maximum. To adjust the idle speed of the gasoline saw, it is necessary to start at maximum speed.
  • Further, the engine power is reduced. To do this, screw L is gradually turned in the opposite direction. Each time it should be turned no more than a quarter.
  • If during the regulation the chain starts to move, it means that you should turn the screw T counterclockwise until the chain stops.
  • Adjust the screw H. To do this, turn on the chain saw to maximum for 10 seconds, at the same time moving the screw a quarter turn. Repeat the operation until you reach peak power.
  • If you set it too high, more smoke will come out of the muffler than usual. With insufficient power, the chainsaw will make characteristic squealing sounds.
  • Adjust screw T at idle speed. To do this, rotate it clockwise until the chain starts to move.
  • Then turn the screw in the opposite direction until the chain stops.
Read more:  How to Adjust a Carburetor Partner 350 Video

This operation is applicable for chainsaws of all manufacturers. STIHL, Husqvarna, Partner, for Chinese chainsaws.

When you set idle speed in the chainsaw, you need to check the operation of the device

We have already said that at the factory, all gasoline saws from all manufacturers are set to the optimal settings. They generate the highest torque with the lowest fuel consumption and wear on parts. The idle operation also minimizes fuel consumption and wear of parts. But over time, the original factory settings gradually get lost.

The fact that it is time to regulate your chainsaw can be understood by the following signs:

  • She’s gaining momentum too slowly.
  • Unable to reach peak power.
  • The engine is unstable.
  • Saw power is noticeably reduced when working under load.
  • There are extraneous noises.
  • Too much smoke appears in the exhaust of the chainsaw, and its volume increases noticeably during sawing.

If at least one of the above signs was demonstrated by your chainsaw, the idle setting should be done as soon as possible.

With prolonged operation with an unbalanced carburetor, temperature conditions are violated, the fuel in the piston-cylinder does not burn completely. As a result, carbon deposits form on the surface of the cylinders and pistons, and micro-caverns in the depths of the metal. All this will very quickly lead the engine to complete disrepair.

But after you have adjusted the carburetor, you should check the operation of the chainsaw. If the adjustment is correct, then:

  • The idle chain spins freely, the sound of the engine running is smooth, without extraneous sounds, the exhaust gas exhaust is insignificant;
  • At maximum speed, the gasoline saw works confidently, including under load, the sound of the engine running is high, but stable, the amount of exhaust gases has increased, but the exhaust is homogeneous, the stream is even, without breaks;
  • Acceleration is smooth and fast after lightly pressing the throttle.

In order to finally make sure that your chainsaw works according to the factory settings, you can watch another corresponding video.

Our catalog contains an extensive range of spare parts, consumables and assemblies for all models of gasoline saws present on the Ukrainian market. For example, the cost of spare parts for a Motor Sich chainsaw is one of the lowest in Ukraine. You can also buy cheap spare parts for other brands of gasoline and electric saws.

How to properly adjust the carburetor on a Husqvarna chainsaw

How to tune the carburetor on a chainsaw Husqvarna Adjusting the carburetor on a chainsaw using three THL screws.

Check not idle speed adjustment.

Finding the highest turnover idle move, for this purpose, 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 for all this, the screw T on the other (S) should be turned clockwise until the oil stops.

Checking not 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 fifteen thousand rpm. The process of fine tuning Husqvarna on the idle chain saw is carefully described. A slightly increased speed is not provided by ignition, as oil becomes dangerous for the engine today. Limit turns are determined by misfiring. If they come, turn the screw H slightly counterclockwise.

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

Husqvarna.Increase idle.Repair carburetor.carburettor adjustment

Raises idle on Husqvarna 555 chainsaw.

Start the chain saw and let it run for about 10 minutes.

Place your Husqvarna 365 chain saw on a level surface with the bar facing away from you and with both bar and chain in contact with the surface.

Find the highest idle speed by slowly turning the low speed jet clockwise and counterclockwise.

When the highest RPM is found, turn the L jet counterclockwise by 1/8. 1/4 turn.

Precise setting of idle speed with T screw

The idle speed setting is carried out with a screw marked with the letter T.

If adjustment is necessary, the idle screw T should be turned clockwise until the chain starts to turn.

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Then turn the screw counterclockwise until the chain is motionless.

The correct number of revolutions is considered when the chainsaw engine works exactly in numerous positions with sufficient supply up to the same number of revolutions when the chain starts spinning.

Do-it-yourself carburetor adjustment on a chainsaw

Chainsaw carburetor adjustment ensures efficient operation of the tool at a workable power version with economical fuel consumption. Adjustments must be made with a clean fuel filter, not an air filter. For a larger number of carburetors, the adjustment is carried out with three screws: for maximum not minimum revolutions, no idle speed adjustment.

The screws H not L regulate 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, the revolutions do not accordingly fall, 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. When, for ease of adjustment, 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. not final, produced on a running warm engine. The exact value of the angles of rotation should be taken from the operating instructions for the specific chainsaw. Failure to follow the manufacturer’s instructions will result in engine damage.

The adjusting screws for maximum H and not minimum L turns are slowly turned clockwise in full, then turned back two turns, other settings are also possible

Factory settings

The factory default setting for the Husqvarna carburetor is the position of the screws (H) and (L), in which a working chain saw is guaranteed to start. For Husqvarna tools, this is one and a half turns from fully tightened screws (H) and (L). In the process of adjustment, you must first set the screws to the standard position, then start the chainsaw and make precise adjustments to the power, the number of maximum revolutions and idle speed.

Tools required for work

Before proceeding with the tuning of the Husqvarna carburetor, you need to take care of having all the tools that may come in handy. To carry out this type of work yourself, you will need:

A regular slotted screwdriver will not work for adjustment, as the adjusting screws on Husqvarna chainsaws may have different cross-sections. You will have to purchase a special, this is a feature of repairing Husqvarna chainsaws, they did everything so that the saw could be repaired only in a specialized Husqvarna service.

About the carburetor device

The carburetor serves to mix the combustible mixture with air, while observing the predetermined proportions. If the correct dosages are not followed, the correct operation of the engine is jeopardized. When a large amount of air enters during mixing of the components, and there is not enough fuel, then such a mixture is considered “lean”.

Over-saturation should not be allowed, since with a large amount of fuel compared to air, malfunctions or engine wear are also possible. Carburetor adjustment is necessary not only before initial use, but also when any abnormalities in its operation are detected. Before starting work with the chainsaw, do not forget to run it in.

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

  • The foundation. It is a special tube that visually resembles an aerodynamic structure. Air passes through it. In the transverse direction in the middle of the pipe there is a damper. Its position can be changed. The more it is pushed into the passage, the less air enters the engine.
  • Diffuser. This is the constricted part of the tube. With its help, the air flow rate increases exactly in the segment from which the fuel comes out.
  • Fuel supply channels. The fuel mixture is contained in the float chamber, then passes into the nozzle, from which it flows into the sprayer.
  • Float chamber. It is a separate structural element, reminiscent of the shape of a tank. Designed to constantly maintain an optimal level of fuel fluid in front of the entrance to the channel where the air comes from.

Not sure which chainsaw to choose? Read our article.

Looking for models that are cheaper, but reliable and time-tested? Pay attention to Russian-made chainsaws.

Alternatively, check out foreign chainsaw manufacturers such as STIHL.