Husqvarna 142 chain saw repair with your own hands video. Husqvarna 142 chainsaw review, from device to repair

Problems, the solution of which can be an adjustment of the carburetor, quite a lot. Adjustment of the carburetor of a chainsaw Husqvarna is necessary when there are such malfunctions as:

  • Increased idle speed;
  • Strong fuming when the tool is running;
  • Difficulty starting a cold or hot engine;
  • Lack of traction and reduced maximum rpm.

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

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

adjust, carburetor, chainsaw, husqvarna

It is considered proper to adjust the idle speed when:

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Note: From the manufacturer (Husqvarna) the idle speed screw was turned from fully wound to 8 full turns and “2 hours” (now it stays on). Recommended idle speed of Husqvarna gasoline engine is 2,900 rpm. 3) Left screw H. adjusts the high RPM mixture enrichment (adjusted in the last turn). It regulates the maximum speed, engine power, temperature, and fuel flow.

Note: The Husqvarna engine should not run at full power for more than 10 seconds!

  • Fully open the throttle (give full throttle) and slowly turn the left screw clockwise until the Husqvarna engine speed decreases (by ear).
  • Then slowly turn the left screw counterclockwise until the engine begins to run unevenly.
  • Then slowly turn the screw a short distance clockwise until the Husqvarna engine runs smoothly.

The carburetor’s purpose, design, and principle of operation.

The carburetor is needed to prepare the fuel-air mixture to power the engine. If the proportions in this mixture are wrong, the operation of the motor is disturbed. If the proportion is not correct, the mixture is called oversaturated, and if there is not enough fuel, the mixture is called lean. Both of these things don’t work well for the engine.

In different models of chainsaws carburetors differ in design, but in the principle of operation they are similar. Air flows at high velocity through the air duct. A damper that closes the channel lets you change the speed of the air jet. Fuel is fed into the channel through the atomizer, where it mixes with the incoming air, forming an air-fuel mixture. The mixture flows into the engine.

The pressure in the float chamber, where the fuel is before mixing, is almost equal to atmospheric pressure. But in the air duct, a vacuum is created so that the fuel is drawn into the air flow. The more the damper is opened, the faster the air moves and the amount of fuel also increases. the engine speed rises. This is a simplified representation of how a carburetor works.

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For efficient, smooth operation of the tool, getting maximum output and at the same time economical fuel consumption requires adjusting the carburetor of a chainsaw. Before adjusting, check the fuel and air filters. they must be clean. Most chain saws have three adjusting screws: idle speed, high rpm, low rpm. Proper carburetor adjustment is evidenced by these signs:

  • Chain does not move when idling.
  • The engine accelerates smoothly and quickly.
  • The sound of the engine is smooth, like a four-stroke engine.

You must be as careful as possible when adjusting the carburetor, because a mistake in the settings can have very serious consequences, up to and including engine failure. If you are not absolutely sure about your abilities, contact a service center.

When to adjust the carburetor?

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

Among the main faults are the following:

  • Increase in idle speed;
  • Large amounts of smoke during operation;
  • Deterioration of starting characteristics;
  • Insufficient power to cut through the tool.
adjust, carburetor, chainsaw, husqvarna

This is not a complete list of all known problems. Sometimes such a procedure as adjusting the carburetor on a Husqvarna chainsaw is necessary after a major repair of the power unit or after maintenance.

The developers of the Husqvarna 137 write in the datasheet that carburetor adjustments should always be performed before and after the tool runs in.

Specifications

Technical characteristics of the chainsaw Husqvarna 142:

  • The chain pitch is 0.325 inches;
  • The chain thickness is 1.3 mm;
  • the number of links is 64;
  • fuel tank capacity. 410 ml;
  • oil tank capacity 200 ml;
  • the bar length is 38 cm;
  • weight of chain saw. 4,6 kg without saw part.

Husqvarna 142 chainsaw

Adjusting the carburetor on your Husqvarna chain saw

Like all other saws, the Husqvarna has the same algorithm for adjusting the carburetor. Therefore, the instruction will be also relevant for other tools and chainsaw models, such as Husqvarna 142. 236.

Before you start, check that the air filter is clean and all other parts are working properly. The fuel supply to the float chamber must work without interruption, and the ignition system is set correctly and has a fresh spark plug.

  • Set carburetor to factory settings. Do this with the engine stopped.
  • Now you can start the engine and be sure to warm it up for a few minutes. Adjusting the idle speed of the Husqvarna 137 carburetor only when the engine is warm.
  • Turn the L screw clockwise to set the highest rpm of the crankshaft, then turn it back a quarter of a turn. Use the T screw to adjust the crankshaft RPM so that the chain doesn’t rotate. It should not be driven without depressing the gas pedal.
  • Now you have to set the maximum rpm and its power. It is enough to connect the tachometer to the ignition system and set the maximum possible revolutions with the gas pedal. Compare it with the data sheet. If they are different, then unscrew or tighten the screw H. By varying the rpm range you can create limits to make the saw efficient and save motor life.
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What to watch out for?

Once you have finished adjusting your Husqvarna carburetor make sure that the engine is running stably and that the saw can easily reach and stop at desired RPM. It is considered abnormal for the chain to rotate at idling speed and it is therefore necessary to re-adjust its relationship with the clutch by means of the screw H.

Don’t forget that it takes some time to adjust the assembly as the Husqvarna chain saw does not immediately react to the screws’ position. This time may vary from 5 to 15 seconds. This time is not prescribed by the table, so you can only find out experimentally.

If after adjustment you see a huge amount of smoke, you need to adjust the fuel and oil mixture. To do this, turn the L screw.

What is the factory setting on the carburetor on a Husqvarna chainsaw??

In order to ensure that the chainsaw will still start even if the setting is wrong, the factory positions of the H and L screws are used. Most Husqvarna chain saws can be started by loosening both screws exactly a turn and a half. Only after this time is it possible to change the settings of the screws to achieve the desired fuel consumption and maximum efficiency. The throttle trigger is also adjusted after these manipulations.

If you still have questions about carburetor adjustment on the Husqvarna 137 chain saw and other models of this line I recommend taking a look at this

Adjusting the carburetor on a Husqvarna chainsaw

Like all other saws, the Husqvarna has the same carburetor adjustment algorithm. Therefore, the instructions will also be relevant for other tools and chainsaw models such as the Husqvarna 142. 236.

Before you start, make sure the air filter is clean and all other components are working properly. The fuel supply to the float chamber must run smoothly and the ignition system must be correctly set and have a fresh spark plug.

  • Set the carburetor to factory settings. Do it with the engine stopped.
  • Now you can start the engine and be sure to warm it up for a few minutes. Adjust the idle speed of the Husqvarna 137 carburetor only when the engine is warm.
  • Turning the L screw clockwise, you need to set the highest revolutions of the crankshaft, then turn back a quarter of a turn. Use the T screw to adjust the crankshaft RPM so that the chain doesn’t rotate. It should not be driven without depressing the gas pedal.
  • Now you have to set the maximum rpm and its power. It is enough to connect the tachometer to the ignition system and use the gas pedal to set the maximum rpm. Compare them with the passport data. If they are different, unscrew or tighten the H screw. By changing the range you can create limits to make the saw work efficiently and save the life of the motor.
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Things to watch out for?

Once the adjustment of the carburetor Husqvarna is completed, you need to make sure that the work of the engine is stable, and the saw easily picks up and resets the necessary revolutions. The rotation of the chain at idle is considered an abnormal phenomenon, so you need to re-adjust its connection to the clutch with the screw H.

Do not forget that it takes some time to adjust the clutch, because your Husqvarna chain saw does not respond immediately to the screws. This time can range from 5 to 15 seconds. This time is not prescribed by the table, so you can only find out experimentally.

If after the adjustment you see a huge amount of smoke during operation, you need to adjust the fuel and oil mixture. For this purpose turn the screw L.

What is the Husqvarna chain saw’s factory carburetor setting??

In order to ensure that the chainsaw still starts even in the case of improper adjustment, the factory positions of the H and L screws are used. Most Husqvarna chain saws can be started with exactly one and a half turns of the two screws. Only then you can change the screw positions to obtain the correct fuel consumption and maximum efficiency. The idle speed is also adjusted after these manipulations.

If you still have questions about carburetor adjustment on the Husqvarna 137 and other models of this range I recommend taking a look at this

Correct tuning

Chainsaw and chainsaw carburetor adjustment is critical for chain saws and other two-stroke engines. Adjustments that give too rich a mixture will cause the saw to have insufficient power, increase carbon and can damage the engine. Proper carburetor tuning will produce maximum power from the equipment, prolong engine cycling, produce minimal exhaust, and run smoothly and smoothly. Most chain saws have three carburetor mounting screws:

  • Throttle stop is an adjustment that determines how much the throttle valve stays open when the throttle trigger is released. If this setting is set low, the engine will stall when the throttle trigger is released.
  • Low Fuel Adjustment (L), an adjustment that controls the fuel at idle.
  • High-speed fuel adjustment (H). controls the proportion of fuel at rated operating speed. This is the most important setting.

It should be noted that some chainsaw designs do not have a high-speed adjusting needle. These saws have a so-called stationary jet that is set by the factory. Fixed-jet carburetors are used to prohibit the operator from making adjustments himself, which can damage the saw. Unfortunately, these factory settings often do not allow the saw to reach its maximum performance.

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