DIY Husqvarna 240 Chainsaw Carburetor Adjustment

How does the carburetor work on a Husqvarna 137 chainsaw?

The chainsaws of THESE models are most often fitted with a Walbro carburetor 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.

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.?

Adjusting the carburetor of your Husqvarna chainsaw

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

Before starting work Make sure the air filter is clean and 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 Husqvarna 137 is made only when the engine is warmed up.
  • Turning screw L clockwise, you need to set the highest revolutions of the crankshaft, then return it back by a quarter of a turn. Using the T screw, I adjust the crankshaft speed 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 the screw H. By changing the range, you can create restrictions to make the saw work efficient and save the motor resource.

What is responsible for supplying a mixture of fuel and oil

For accurate delivery of fuel with oil, the work of the fuel pump is used, which is mechanically driven from the crankshaft. The carburetor itself is equipped with a diaphragm and a special needle valve, which are responsible for regulating the pressure in the system. Thanks to them, the correct operation of the metering chambers and the pump is organized, which improves the operation of the chainsaw.

What is responsible for the air supply

Two dampers are responsible for the air supply, installed on the diffuser chamber. The first can regulate the amount of air at the moment the accelerator is pressed and is called the throttle, and the second ensures the restriction of the air supply at the moment when the chainsaw is cold started. To facilitate starting, the damper is closed, which means that the mixture becomes rich, as it is saturated with a large amount of fuel. It is easier to work in this mode, but since it increases fuel consumption, this mode does not apply throughout the entire operation. The saw is worn out.

A check valve is used to spray fuel into the cylinders.

The principle of operation is simple: it limits the return of the mixture back to the chamber. All the main malfunctions of chainsaws, most often, manifest themselves when this mechanism does not work properly.

  • The most common mistake is storing the instrument for too long. The fact is that with prolonged inactivity, the valve sticks and either fills the cylinder with fuel, or simply does not open.
  • The second problem is an increase in the amount of air in the mixture, caused by its suction from the outside when the valve does not work properly. It is no longer possible to adjust here, since in this case only valve repair or replacement helps, since the saw will not react to the adjusting screws.

Unlike the car, the tuning of the chainsaw carburetor provides for three adjusting screws that are responsible for the quality of the mixture, the quantity and the nominal crankshaft speed of the Husqvarna engine:

  • Screw L. designed to adjust the number of revolutions when operating in medium modes and regulates low revolutions;
  • Screw H. adjusts the number of high revolutions and thrust of the installation;
  • T. designed to adjust the total amount of fuel and adjust the operation of the throttle assembly.

It is not recommended to touch the first two screws, and not having special skills. The problem is that if you set them incorrectly, the carburetor will NOT be able to start the engine, or even start it in the wrong operating modes. Such adjustment of the screw can lead to its early wear and failure. This principle is embedded in many devices.

Read more:  Adjusting The Carburetor Of Any Chainsaw With Your Own Hands.

Settings parameters do not show any table. Therefore, you should not look for these data in special literature, but only strictly follow the instructions. The table in the passport has only informational value, Regarding the characteristics of the engine.

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, i.E. 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:

What is worth Pay attention?

Once your Husqvarna carburetor adjustment is complete, you need to make sure that the engine is running smoothly and that the saw can easily rev up and down. It is considered abnormal to rotate the chain at idle speed, so you need to re-adjust its connection to the clutch with screw H.

Do not forget that the unit is NOT set up immediately: you need to wait a while, as the Husqvarna chainsaw does NOT immediately react 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.

What is a factory setting for a Husqvarna chainsaw carburetor?

In order for the chainsaw 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 the second models of this line, I recommend watching this:

How to repair a Husqvarna carburetor with your own hands?

During operation and diagnostics, defects in the carburetor may be found. Most of them can be eliminated on their own with a minimum of knowledge and without contacting a specialized repair center.

Among the methods of elimination are:

  • Replacement of various gaskets at the joints of sealed parts;
  • Cleaning or replacing the filter elements of the carburetor;
  • Replacement of pump elements or valves;

Almost all of the above parts can be positioned as a repair kit, which is used for minor repairs of carburetors. After installing them, the carburetor of the Husqvarna 137 chainsaw can forget about the malfunction for a long time, and the regulation will become easier.

What is important to remember the consumer

Chainsaw “Huskvarna 240”, specifications which should help you make the right choice, after purchase, a fine-tuning file is required. In this case, we are talking about setting carburetor. It is also important to remember that this equipment has oil flow control systems for chain lubrication, but it often happens that the oil tank empties faster than the tank dedicated to the fuel mixture.

How to properly adjust the carburetor of a Husqvarna chainsaw with your own hands

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 low-quality fuel. Consider the principles and procedure for adjusting the carburetor of a Husqvarna chainsaw.

How to properly adjust

For this, the device has 3 adjusting nozzles. The idle speed screw (T) is located at the top of the carburetor. Below there is a pair of jets for adjusting the fuel supply at minimum (L) and maximum (H) rpm, left and right, respectively.

The procedure for adjusting the carburetor on a Husqvarna chainsaw is as follows:

  • Warm up for 5 minutes.
  • Turning screw L, we bring the engine to the highest speed in an unloaded state and return it back by a quarter of a turn.
  • Hold the throttle button with one hand for 15 seconds. At this time, we turn the jet H to the right until it stops and reaching the maximum speed. Then we turn it back one and a half turns, or Until the “squeal” of the engine disappears.
  • With the throttle released, turn the idle screw (T) clockwise until the chain does NOT move. After that, we rotate it in the opposite direction until the chain stops moving.

During the adjustment process, a situation may arise in which the chainsaw stalls. This may be due to excessively twisted jets, too rich or poor mixture.

If this happens, it is necessary to tighten the jets of the minimum and maximum speed until they stop. Then turn them back one and a half turns and try to get dust.

How to adjust the carburetor on a Husqvarna 240 chainsaw?

Any technique is subject to breakdowns from time to time. The main malfunctions of the Husqvarna 240 chainsaw are associated with the repair of the carburetor, the second components of the fuel system, with malfunctions of the oil pump. If the oil pump breaks down, the chain for the Husqvarna 240 chainsaw stops rotating due to lack of lubrication. Also, damage to the gas tank or fuel hoses can be a prerequisite for why gas is leaking from the saw. If the saw has completely stopped starting, first of all you should make sure of the quality of the fuel mixture, check the spark plug spark. If necessary, the spark plug is cleaned or replaced with a new one, the carburetor is adjusted.

Adjustment of the carburetor is also required in cases where the chainsaw starts to start poorly, stalls under load, and also if the type of fuel or operating conditions have changed. Carburetor is adjusted after preliminary cleaning of air filters and engine warming up.

Read more:  Oil Pump Does Not Work On Chainsaw

Then proceed according to the following algorithm:

  • Screw L turns to the maximum. Then immediately return the screw a quarter of a turn back.
  • Holding the throttle handle a quarter turn Turn screw H.
  • Release throttle and turn screw T clockwise until the chain starts moving. Then immediately turn the screw back until the chain stops.

The location of the corresponding screws is shown below:

DIY Husqvarna 240 chainsaw carburetor adjustment. 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 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. a prerequisite may be a stuck needle valve.

The factors leading to such changes can be the following:

  • Strong vibration will damage the protective cover and the adjusting jets are unscrewed, changing the settings. In this case, it is possible to adjust the carburetor on the chainsaw.
  • Wear of elements of the piston system. Adjusting the carburetor in such a 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, washed 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, he proceeds to dismantle the carburetor, and then to check the piston system.

Husqvarna 240 is back in the carburetor. Construction blooper or what is it?

Carburetor for Husqvarna Chainsaw HUSQVARNA 240 carburetor problem. One of the most.

Chainsaw “Husqvarna 240”, the technical characteristics of which you can see below. It is the equipment that follows the Husqvarna 236 mowing line. If a comparison is made between these two options, it should be noted that the latter has a higher power, a slightly longer tire and has an engine that saves fuel up to 25%.

The Huskvarna 240 chainsaw, which does not need to be repaired as often, is an environmentally friendly tool that is very important for some consumers. The volume of harmful emissions into the atmosphere is reduced, and the number of cuts on one fuel for refueling increases. Quite often, the products of the aforementioned Swedish company are compared to the manufacturer of the Stihl chainsaw. As an advantage of the former, it should be noted that a primer is available to facilitate start-up. However, as practice shows, this does not have a significant effect on the equipment startup process.

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 a light brown carbon deposit, it can be considered intact.
  • If traces of gasoline are found on the spark plug, the carburetor should be readjusted. This happens because it supplies an excess amount of fuel to the internal combustion engine, we fill 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 did 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 unit must be replaced with a similar.

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.

DIY carburetor repair

If in the course of carrying out a complete diagnosis of a 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.

Gaskets, diaphragms and rocker needle valve can be found in the repair kit, which is available for every Husqvarna chainsaw carburetor.

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 dust 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 control levers of the air and throttle valves. Then Unscrew the carburetor fixing screws.

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 dismantled with the usual open, the fuel pump cover is fixed with one wide screw.

Read more:  How to Dilute Gasoline with Stihl Chainsaw Oil

Below is presented. Seeing which it will become clear how exactly you can repair the carburetor without contacting a Husqvarna service center.

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 if such faults occur as:

  • Increased idle speed;
  • Strong smoke during tool operation;
  • Difficulty starting a cold or hot engine;
  • Lack of traction and reduced maximum speed.

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

Adjustment carburetor

Chainsaw “Husqvarna 240”, carburetor setting that you can do yourself. It is a tool that cannot be repaired at home. However, the configuration of the mentioned assembly can be performed independently, for this it is necessary to learn how to distinguish the screws. Each of them has a letter designation, the first. For adjusting low rpm, another for adjusting high rpm, and a third. To adjust idle speed.

Although the factory setting is considered optimal, the screws can be used to adjust the motor operation. This is sometimes necessary when climatic conditions differ from those Recommended by the manufacturer. To increase the speed, the indicated first two screws must be turned clockwise. The sequence for using the screws is as indicated above. If you have any doubts, it is better to consult a specialist, because if the carburetor chainsaw “Husqvarna 240” is not adjusted correctly, the engine may be damaged.

Tools needed for work

Before you start setting up the Husqvarna carburetor, you need to take care of the presence of all the tools, which may come in handy. To carry out this type of work yourself, you will need:

The structure and principle of operation of the Husqvarna carburetor

To successfully tune your Husqvarna chainsaw carburetor, you need to know its design and understand how it works. In fact, everything is not as difficult as it seems at first glance.

The saw carburetor has a built-in fuel pump, which is responsible for transporting a mixture of gasoline and oil, as well as a diaphragm, a needle valve from the rocker arm. Their joint work allows metering the fuel supply to the main chamber and two dampers.

One of the valves is designed to adjust the fuel supply to the cylinder when the gas is pressed, it is called the throttle, the second is responsible for restricting the air supply from the air filter to facilitate starting a cold Husqvarna chainsaw. At the moment when the operator cuts off the air supply to the carburetor with the help of the air damper, the fuel mixture becomes leaner and its supply to the cylinder increases, due to which the chainsaw starts much easier than in the case when a cold start is carried out in normal mode.

In the operation of the Husqvarna carburetor, a nozzle valve is involved, which atomizes the fuel and prevents air from entering the main chamber. Often, problems with saw operation can be caused by defects in this particular element. For example, the valve, if the chainsaw is not stored properly, may stick, the fuel supply will stop, which will make the engine impossible to operate. Also, irregularities in the operation of the injector can become a prerequisite for air leakage into the main fuel chamber of the carburetor. In such cases, correcting the position of the adjusting screws will NOT correct the situation, it will be necessary to repair or replace the unit.

By setting the quality and quantity of the mixture, as well as the number of revolutions of the crankshaft in idle mode, there are three adjusting screws installed in the carburetor body:

  • Screw (L). adjusts the amount of fuel in the low and medium speed modes;
  • (H). is responsible for traction at high speeds and their number;
  • (T). changes the position of the throttle valve, thereby regulating the amount of fuel mixture entering the cylinder and the operation of the engine of the tool in idle mode.

What is important to remember the consumer

Chainsaw “Huskvarna 240”, specifications which should help you make the right choice, after purchase, a fine-tuning file is required. In this case, we are talking about setting carburetor. It is also important to remember that this equipment has oil flow control systems for chain lubrication, but it often happens that the oil tank empties faster than the tank dedicated to the fuel mixture.

Husqvarna 240 is back in the carburetor. Construction blooper or what is it?

Carburetor for Husqvarna Chainsaw HUSQVARNA 240 carburetor problem. One of the most.

  • Brake lever;
  • Economical fuel consumption;
  • Anti-vibration system.

But this consumer list is not considered complete. They love the presence of a brake lever in the model, it attracts both the ergonomic design, the low exhaust volume and the chain tensioner.

DIY Husqvarna 240 Chainsaw Carburetor Adjustment

Chainsaw specifications Husqvarna 240

At the heart of the Husqvarna 240 is a 2-stroke engine with carburetor. Powered by a gasoline-oil mixture. The service life has been increased due to improvements in the crank assembly and a special coating of the cylinder. Fuel economy is reduced by 20% thanks to the innovative X-Torq system, which also reduces the harmfulness of exhaust gases. Capacious fuel tank and low fuel consumption extend the operating time of the tool, without interruption for refueling.

The rest of the saw has the following technical characteristics:

  • Productivity. 2 liters. From.;
  • Chain pitch. 3/8 inch;
  • Fuel tank capacity. 300 ml;
  • Oil tank. 200 ml;
  • Tire length. 40 cm;
  • Weight. 4.7 kg.