Replacing Carburetor On Chinese Chainsaw

How does a chainsaw carburetor work??

The main purpose of the carburetor is to mix fuel with air in the required proportions. If the latter are violated, this is almost instantly reflected in the operation of the engine.

replacing, carburetor, chinese, chainsaw

Stihl MS 181 C BE chainsaw carburetor

Chainsaw carburetors may vary in design. However, their basic elements and the principle of operation remain approximately the same.

Carburetor device:

  • The foundation

This is a wind tunnel, across which the air damper is located. with its help the intensity of the air supply is regulated.

  • Diffuser

This part is located where the base tube narrows. here the air flow speed increases, i.e. air is always supplied to the carburetor under some pressure.

  • Spray

In this area, the fuel comes into contact with the air flow. Fuel enters the atomizer from the float chamber through the nozzle (metering device).

  • Float chamber

This is a container that allows you to keep the fuel mixture in a stable state.

Structural diagram of a chainsaw carburetor

The chainsaw carburetor works according to the following principle:

  • when the engine is started, the main flap opens and a stream of air is supplied into the air channel at a certain speed;
  • the air flow rate, as well as the level of the float in the chamber, are regulated by the position of the damper, namely, due to the difference in pressure in the float chamber and the air channel;
  • the fuel from the float chamber is sucked into the nozzle, and from there into the diffuser;
  • passing through the diffuser, the air captures the fuel entering there;
  • the resulting mixture is fed into the cylinder chambers through the inlet channels.

The principle of operation of the chainsaw carburetor

The pressure in the float chamber is approximately equal to atmospheric, but in the air channels of the carburetor, when the engine of the chainsaw is started, a vacuum occurs. Opening the damper increases the air flow rate. As a result, more fuel enters the carburetor, and the number of engine revolutions increases.

How to recognize carburetor malfunctions?

Typical carburetor malfunctions are easy to recognize. They are expressed in the fact that the engine of the chainsaw starts up and immediately stalls or does not show signs of life at all. Well, or it consumes fuel with might and main, instead of the intended power, producing clouds of black smoke and aggressive vibrations.

Chainsaw carburetor operation diagram

Carburetor settings can be affected by:

    lack of fixing the adjusting screws;

Chainsaw adjusting screws

New CPG chainsaw Husqvarna 365

Chainsaw air filter with nylon insert

If any problems are found, they should be rectified immediately. But how do you know if the carburetor is the problem? To do this, watch how your tool works.

A list of typical signs that carburetor settings are out of tune include:

  • Unstable motor operation

As a rule, the reason for this is the use of the wrong (lean) fuel mixture.

  • Excessive consumption of fuel

It is expressed in an increased emission of exhaust emissions, which become black. This means that the fuel is not completely consumed, i.e. oversaturated mixture.

Carburetor set correctly. saw starts the first time

  • Arbitrary changes in engine power

May be due to damage to the fastening of the adjusting screws or the protective cap.

  • Increased fuel consumption accompanied by vibrations and pops

It speaks of critical wear of the piston group, so adjusting the carburetor will postpone the overhaul only for a while.

  • Sneezing and jerking of the engine

This picture is observed when the carburetor channels are clogged or its filters are malfunctioning. In this case, the adjustment should be carried out only after thorough flushing of the assembly.

Chainsaw fuel filter

Despite the fact that the carburetor is the most difficult part of the engine, you should not be upset if it detects malfunctions in its operation. Instead, you need to arm yourself with some tool, a constructive node diagram and healthy logic.

Chainsaw carburetor being repaired

What is the primary adjustment for??

In the first hours of operation, the 2-stroke engine of the chainsaw requires running-in, on which the quality of its further work depends. During the running-in process, the initial carburetor adjustment is performed. the optimal parameters for the preparation and supply of the fuel mixture are set.

Chainsaw initial break-in: working with thin material

Most modern chainsaws are sold adjusted. Nevertheless, the quality of the factory settings does not interfere with checking. in the end, you will have to work with the instrument.

The first time you start the chainsaw, it should be running gently. Therefore, for several hours after the start, it is recommended not to overload the engine and only cut small branches and trunks up to 10 cm thick.

To insure against malfunctions in the carburetor of the chainsaw, simple rules will help:

    Always mix gasoline and oil in accordance with the manufacturer’s numbers.

The proportions of the fuel mixture for the chainsaw engine

The chainsaw must start correctly, ensure a stable sprocket speed and smooth power increase / decrease. When the engine is running, there should be no extraneous knocks, pops and noises.

Professional hand-held chainsaw at work

The main thing during the initial running-in of the tool is to make sure that the fuel consumption corresponds to the power used, i.e. in practice, the saw should not go out, “sneeze”, smoke and work in jerks.

DIY disassembly: nothing complicated

First of all, you need to prepare a place for disassembly. This can be a workbench or a regular table. In addition, you need a rectangular piece of cloth or cardboard. on it you will neatly fold the carburetor parts. And, finally, a tool: for disassembly you will need a set of open-end wrenches and screwdrivers, a special cleaning compound and an ultrasonic cavitation bath.

Chainsaw carburetor repair tool

First you have to dismantle the chainsaw carburetor. This is done in this order:

    To get to the carburetor, you need to remove the top cover of the chainsaw, which is fixed with three bolts.

Removing the carburetor cover

Removing the fuel hose and drive rod

Removing the throttle cable

After removing the gasoline hose, the carburetor is ready for disassembly

Disassembly of the carburetor must be carried out in the manner prescribed by the design and functional solutions of its elements. Chainsaw carburetor parts do not differ in size, so they need to be folded carefully and in order, trying not to lose anything.

Dismantling the chainsaw carburetor in the photo

After disassembly, it is necessary to carry out a troubleshooting and replace damaged or worn parts. Next, the entire set should be rinsed with a special product, dried and wiped with a dry, lint-free cloth. The jets and tubes of the assembly must be blown out with compressed air, or, in order to more thoroughly remove formations on their inner surfaces, they must be sonicated beforehand.

DIY chainsaw carburetor repair instructions

A chainsaw is needed in construction, in gardening, and in landscaping. its presence greatly simplifies the implementation of a number of tasks for wood processing. The main unit of this tool is the engine, the operation of which largely depends on the state and settings of the carburetor. This is where the fuel mixture is prepared. This means that if the saw does not start, stalls or does not provide the required power, it is likely that the reason for this is improper operation of the carburetor. Fortunately, you can handle this yourself in many cases. Only for this you need to know and understand the device and principle of operation of this unit and, of course, the chainsaw itself.

Carburetor Tuning: Highlights

Reassembly of the carburetor is carried out only after complete cleaning, drying and blowing with compressed air. At the same time, do not forget that some gaskets and seals, even if there is no damage, must be replaced.

You can start adjusting the carburetor provided it is correctly troubleshooting, high-quality assembly and flawless re-installation on the engine.

Carburetor setting principles:

  • screws H and L adjust the ratio of air and combustible mixture, i.e. throttle position. Tightening the screws clockwise leads to a depletion of the mixture and the transition of the engine to low rpm. When unscrewing (counterclockwise), the mixture is enriched, and the engine speed increases;
  • screw T is responsible for adjusting the idle speed: turning it clockwise gives an increase in their number, against. a decrease;
  • screws are adjusted in L-H-T order.

Chainsaw Carburetor Calibration

The general adjustment algorithm looks like this:

  • Initially, the highest idle speed is found by turning the screw L and then returning it by ¼ turn counterclockwise. If the chain rotates at idle speed, turn the screw T in the same direction until it stops completely.
  • With the engine warm, running at full speed, turn the screw H by ¼ turn to the left, then let the engine run for 10 s, check the maximum speed using a tachometer. It must correspond to the number indicated in the instrument’s passport.
  • After the calibration with screws L and H, the idle speed is adjusted with screw T. If done correctly, the engine will run evenly in all positions.

Memo for calibrating the carburetor on the body of the chainsaw

Upon completion of the adjustment, it remains to reinstall the cover of the chainsaw with an insulating gasket, after which you can start the main work. If the settings are correct, the chainsaw engine will get the optimal fuel mixture. This will ensure its normal efficiency, as well as the overall comfort and safety of working with the tool.

How to replace Carburetor on a Stihl chainsaw

Replacing the carburetor Stihl MC180

In addition to the above malfunctions, other malfunctions may occur with the chainsaw. This mainly concerns consumables that have their own service life. So, in the process of work, the outcome of the tire, the drive sprocket and other parts may occur.

To prevent the occurrence of more complex malfunctions, it is necessary to timely change such parts. With this knowledge, you will be able to repair chainsaws such as Druzhba 4, Stihl 180, Husqvarna, Ural, with your own hands. This will significantly reduce repair costs.

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How does a chainsaw carburetor work??

The main purpose of the carburetor is to mix fuel with air in the required proportions. If the latter are violated, this is almost instantly reflected in the operation of the engine.

Chainsaw carburetors may vary in design. However, their basic elements and the principle of operation remain approximately the same.

This is a wind tunnel, across which the air damper is located. with its help the intensity of the air supply is regulated.

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This part is located where the base tube narrows. here the air flow speed increases, i.e. air is always supplied to the carburetor under some pressure.

In this area, the fuel comes into contact with the air flow. Fuel enters the atomizer from the float chamber through the nozzle (metering device).

This is a container that allows you to keep the fuel mixture in a stable state.

The chainsaw carburetor works according to the following principle:

  • when the engine is started, the main flap opens and a stream of air is supplied into the air channel at a certain speed;
  • the air flow rate, as well as the level of the float in the chamber, are regulated by the position of the damper, namely, due to the difference in pressure in the float chamber and the air channel;
  • the fuel from the float chamber is sucked into the nozzle, and from there into the diffuser;
  • passing through the diffuser, the air captures the fuel entering there;
  • the resulting mixture is fed into the cylinder chambers through the inlet channels.

The principle of operation of the chainsaw carburetor

The pressure in the float chamber is approximately equal to atmospheric, but in the air channels of the carburetor, when the engine of the chainsaw is started, a vacuum occurs. Opening the damper increases the air flow rate. As a result, more fuel enters the carburetor, and the number of engine revolutions increases.

Repair is not likely if you do not know how the mechanism being repaired works. Repair of ignition in a Chinese chainsaw, how to proceed it is necessary to remove the flywheel, under it. If you know the mechanism of operation and the constituent elements of the device, the breakdown will be found even earlier.

Tubes in which a transverse flap is provided to regulate the air flow.

Diffuser. constriction allowing to increase the air flow rate. Placed near the fuel inlet.

  • An atomizer that serves to supply fuel (indicated by a fuel needle in the diagram).
  • Float chamber, where the fuel level is adjusted at the inlet channel.
  • Diagram showing the process of interaction of fuel and air flow

Description of the principle of operation: with the help of an air jet, fuel is sprayed in the diffuser area, and a mixture is created that enters the cylinder cavity. With an increase in the amount of fuel supplied, the speed in the engine increases. Different carburetors work according to the same principle.

Correction of the maximum number of revolutions

New chainsaws are supplied from the manufacturer with pre-configured carburetors. This is called a standard setting. But for normal break-in, it is necessary to lower the maximum engine speed in order to tune the carburetor. After starting the chainsaw, fine adjustments are required to maximize engine efficiency.

In addition, a signal for cleaning and adjusting. this is an increase in fuel consumption, which negatively affects the operation of the exhaust system. Simply put, the chainsaw starts to breathe heavily, and the muffler becomes clogged with carbon, which in turn leads to a decrease in power. With a lack of fuel in the mixture, engine parts are poorly lubricated and premature wear occurs. In addition, a poor-quality mixture can lead to engine stuck due to overheating (this is one of the reasons why the chainsaw does not start).

Correction is necessary when the engine does not idle, does not run, or does not develop full power.

Carburetor adjustments should be done with clean air and fuel filters.

Before adjusting the carburetor on the Partner 350 chainsaw, you must locate the H9raquo; screw. It is required to adjust the maximum speed. It should be rotated clockwise, while if it is necessary to reduce the number, then the movement of the screw should be directed in the opposite direction.

The maximum frequency should be set between 11500 and 15000 rpm. If this value is exceeded, then the engine will work for wear, which will certainly lead to a malfunction during ignition. By turning the screw under the letter “H9raquo; you need to consider how the ignition occurs. If malfunctions occur, then the rotation should be stopped by turning the screw counterclockwise.

How to adjust the carburetor

The chainsaw setting algorithm is quite simple and consists of the following steps:

  • Engine tuning for smooth operation at low rpm.
  • Adjusting the carburetor for the mixture at maximum speed.
  • Fine tuning the carburetor at idle speed.
  • Check your chainsaw in all modes.

The carburetor should be adjusted after starting the engine a little and warming up.

Now let’s look at how to fine-tune carburetor chainsaws. Almost all carburetor models have three adjusting screws. The screw (T) is responsible for fine tuning in standby mode. The screw (H) will adjust to the maximum speed. The screw (L) controls the mixture formation at low rpm. By tightening the screws (L) and (H), the fuel supply and the mixture are depleted, and the revs increase accordingly.

When carburetor adjustment is required

As already mentioned, the new chainsaw already has standard fuel settings. But for proper break-in, it is recommended to limit the maximum engine speed, and this is done using the adjusting screws located on the carburetor body. Also, after running in, it will be necessary to again make a more accurate adjustment of the supply of the combustible mixture.

In addition, you will have to adjust the carburetor in the following cases:

  • due to strong vibration, the factory settings are lost;
  • The internal combustion engine does not start well and immediately stalls;
  • The internal combustion engine starts up, but the speed does not develop, and it stalls;
  • the piston group is worn out. in this case, adjusting the carburetor of the chainsaw is possible as a temporary measure;
  • the engine does not function at idle;
  • increased gasoline consumption, due to which the unit emits a lot of smoke, the muffler and spark plugs become dirty with carbon deposits, the engine power decreases.

You should be aware that the carburetor can only be adjusted correctly if:

  • cleaning filters (gasoline and air) are not contaminated;
  • the jets and the channels that fit them are clean;
  • membranes are not damaged;
  • the needle valve is in good working order and the required volume of the fuel mixture enters the float chamber.

To adjust the carburetor of imported chainsaws, you must adhere to the following rules.

  • Before adjusting, if possible, warm up the engine at idle or minimum speed for about 10-15 minutes.
  • By rotating the “L” regulator, the engine is operated so that it produces at idle one and a half to two thousand revolutions per minute. But you should pay attention to how the engine picks up speed. When pressing the throttle lever, acceleration should go quickly and evenly. If a “dip” of revolutions is detected, the screw should be slightly unscrewed until this phenomenon is eliminated, since it is caused by insufficient enrichment of the fuel mixture.
  • When the mixture is adjusted at low speed, start tightening the “T” screw until you notice the saw chain turning. After that, the screw should be unscrewed by half or a third of a turn, observing the behavior of the clutch mechanism. Normally, the saw should not rotate at idle speed.

The screw “H” compensates for the underestimated or overestimated speed due to the change of the type of fuel, changes in the concentration of oil or humidity of the ambient air.

Screw “H”, not having enough experience, it is better not to adjust. If the tuning of the carburetor of the chainsaw is carried out by an incompetent person, there is a great danger that a too lean mixture will enter the combustion chamber at high speeds, especially under load. Such operation of the engine will inevitably lead to rapid wear of its piston system and to a failure in the ignition system.

It is possible to start adjusting high speeds if the person who will perform the tuning has the knowledge and skills in adjusting carburetor engines. The master-tuner must have a special device. a tachometer or a multimeter with an oscilloscope function.

Setting up the carburetor of a chainsaw, namely, high engine speed, follows a simple scheme.

  • It is necessary to tighten or unscrew the screw “H” until at maximum gas the engine develops about 15 thousand revolutions per minute (according to the tachometer) or the value indicated in the manual for this unit.
  • When using an oscilloscope, the spark discharge frequency should be between 230 and 250 Hz. It should be borne in mind that under load, the frequency can decrease by approximately 10-15%.

The carburetor of a Chinese chainsaw should be adjusted in the same way as described above. There are holes on its body, into which, in order to adjust the engine speed, you need to insert a flat screwdriver. Each hole is labeled with one of the three letters. As a rule, you can see the letter “T” near the upper hole, and the letters “L” and “H” near the lower ones (shown by arrows).

The Chinese chainsaw Carver (CARVER) has the same arrangement of screws. The following figure shows what a Chinese chainsaw carburetor looks like outside the unit body.

Immediately after starting work, the motor stops. How to remove the clutch from a Chinese chainsaw? Part. It happens that in general it does not start working. repair of a Chinese chainsaw: you need to remove the handle of the chainsaw and who, like a carburetor. The prerequisite for this task is an excess of air and a lack of fuel.

Cleaning the carburetor on a Chinese chainsaw Repairing the carburetor adapter for the benzotrimer Service website.

To implement the adjustment of the chainsaw carburetor, you will have to use only 3 screws (some models are equipped with just one screw). Screws L and H are identical only from the outside, their functions are completely different

Each screw has its own letter designation:

  • “L”. to adjust low rpm;
  • “H”. to adjust the upper speed;
  • “T”. to adjust idle speed (models in which one screw owns only this).

The factory adjustment is considered to be more suitable, and the screws are used to adjust the operation of the motor for special situations (work, in difficult weather conditions). Chainsaw is customizable with special inventory

Adjustment is made using screws L and H. To increase the speed, they turn in the clockwise direction. Stihl chainsaw carburetor how to recognize the nut and / or remove it from. How to remove the clutch from a Chinese chainsaw? Part of replacing an asterisk on a Chinese chainsaw. And to reduce the speed. in the reverse direction.

Correctly adjusted chainsaw carburetor ensures efficient operation at full power with the most economical fuel consumption.

The need to adjust the carburetor of a chainsaw arises infrequently, since the adjustment is initially carried out by the manufacturer to achieve optimal operation. The adjusting screws are designed for more accurate adjustment of the chainsaw carburetor, if necessary.

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When and why does this need arise??

Among the reasons for the failure to fix the adjusting screws, the most common are:

  • Strong vibration or damage to the protective cover. It rarely happens, but it does happen.
  • Serious engine wear (piston). Of course, in this case, it is worth taking more care of repairing the chainsaw engine, but still adjusting the carburetor can improve its functionality for a while.
  • Blockage in the carburetor due to damaged air filter, poor quality gasoline, or scale formation. In this case, in addition to adjusting the carburetor, flushing it cannot be avoided.

What signs indicate the need to adjust the chainsaw carburetor?

  • Firstly, the engine does not start, or it starts, but immediately stalls. This is most often due to a lean mixture.
  • Secondly, a significant increase in fuel consumption and exhaust emissions. An increase in exhaust emissions indicates that the fuel does not burn completely, which means that the cause may be oversaturation of the fuel mixture.

Cheap Chinese HUZTL 15 Carburetor for a Stihl

The chain saw carburetor adjustment scheme may differ slightly depending on the manufacturer (the process of adjusting the chainsaw carburetor of a particular brand and model is described in detail in the operating instructions), but the general principles remain the same for all brands. The purpose of the saw adjustment is to change the quantity and quality (richness) of the fuel mixture supplied to the engine cylinder.

To find out how to adjust the carburetor on a chainsaw, you should learn to distinguish between three screws (some models have only one).

The L and H screws are similar only in appearance, in fact they are different

Each screw has its own letter designation:

  • “L” is for setting low rpm;
  • “H” is needed to adjust the upper speed;
  • “T” is needed to adjust the idle speed (models with one screw only have it).

There are mandatory safety requirements that must be observed when adjusting the carburetor of any chainsaw:

  • Make sure the chain is facing away from you.
  • The saw must be firmly positioned on a level surface, and its cutting edge must not touch any objects.

Please note: the exact values ​​of the angle of rotation of the adjusting screws can be found in the operating instructions for your specific model of chainsaw. Strict adherence to the manufacturer’s instructions will help you avoid engine damage.

The process of tuning the carburetor of a chainsaw consists of two stages: basic (engine off) and final (running warm engine).

Slowly turn the maximum and minimum speed adjusting screws (H and L) clockwise until they stop, then turn counterclockwise 1.5 turns.

Every carburetor owner should have the necessary tools to adjust this system. There are three adjusting screws that are located on the body of the device. They have their own markings:

  • L. screw for low speed correction.
  • H. screw for high speed adjustment.
  • T. regulates the idle speed, in most cases it is used for experiments.

Chainsaw air filter

Before adjusting the carburetor, you need to prepare the device:

  • The engine warms up, that is, it starts about 10 minutes before the repair, and turns off when you start work (see how to start the chainsaw).
  • The air filter is checked and washed.
  • The chain is stopped by turning the screw T as far as it will go (see chain oil).

Step-by-step disassembly of the carburetor

The process of disassembling the carburetor plays a huge role in how to adjust the carburetor on a chainsaw. The carburetors of various chainsaws do not fundamentally differ from each other, for this reason, we will consider the disassembly of the Partner chainsaw. All elements must be carefully removed and folded to facilitate the next assembly.

First of all, you need to prepare a place for disassembly. This can be a workbench or a regular table. In addition, you need a rectangular piece of cloth or cardboard. on it you will neatly fold the carburetor parts. And, finally, a tool: for disassembly you will need a set of open-end wrenches and screwdrivers, a special cleaning compound and an ultrasonic cavitation bath.

Chainsaw carburetor repair tool

First you have to dismantle the chainsaw carburetor. This is done in this order:

  • To get to the carburetor, you need to remove the top cover of the chainsaw, which is fixed with three bolts.
    Removing the carburetor cover
  • After removing the cover, do not forget to remove the gasket, which is an integral part of the air filter, and the body of the latter, for which you need to unscrew the corresponding nuts and / or remove it from the clips.
  • There is a fuel hose on the right side of the carburetor, it must be removed together with the air damper drive rod, not forgetting to pull it off the fitting on the left.
    Removing the fuel hose and drive rod
  • After removing the hose and rod, remove the throttle cable tip from the fixing socket and finally dismantle the gasoline hose.
    Removing the throttle cable
  • After that, the carburetor can be removed from the mountings for subsequent disassembly.
    After removing the gasoline hose, the carburetor is ready for disassembly

Disassembly of the carburetor must be carried out in the manner prescribed by the design and functional solutions of its elements. Chainsaw carburetor parts do not differ in size, so they need to be folded carefully and in order, trying not to lose anything.

After disassembly, it is necessary to carry out a troubleshooting and replace damaged or worn parts. Next, the entire set should be rinsed with a special product, dried and wiped with a dry, lint-free cloth. The jets and tubes of the assembly must be blown out with compressed air, or, in order to more thoroughly remove formations on their inner surfaces, they must be sonicated beforehand.

Most common tool breakdowns

Unfortunately, regardless of the build quality, chainsaws break sooner or later. In frequent cases, repairs can be done by hand. But in order to do this, you must first determine the cause of the problem. Often a failure in work is associated with a malfunction of the power unit or other parts of the chainsaw.

So, if we talk about the power unit, then the problem may arise in the ignition, fuel supply and starter. Also, the problem may lie in the piston and even in the cylinder. You can determine the malfunction of the power unit by the following signs:

  • complete engine failure during operation;
  • the unit starts up, but immediately stalls;
  • the engine is not able to develop the required power;
  • interruptions occur.

You may be interested in an article on how to repair a Partner 350 chainsaw.

Read about how to make a screw log splitter with your own hands in our article.

Before proceeding with any action, it is necessary to carefully analyze the situation.

How to replace a carburetor on a chainsaw

How to set up a carburetor on a chainsaw: recommendations

Chainsaw carburetor. this is one of the main components of this tool. He is responsible for the fuel supply. The efficiency and power of the equipment depends on how correctly this unit functions. Timely adjustments are also economical.

Before adjusting the carburetor on a chainsaw, you should know that adjustments to this part of the device are rarely carried out. As a rule, the factory setting is sufficient for normal operation. However, if a more precise adjustment is required, then special screws can be used. Before starting such work, you need to understand the subtleties and nuances of the process.

Specialist’s recommendations for working with the Druzhba chainsaw carburetor

Before adjusting the carburetor of the Druzhba chainsaw, you must carry out maintenance on the tool. It involves flushing the engine, cleaning the carburetor, replacing the spark plug, checking the chain tension, cleaning the air filter, warming up the engine and adjusting the idle speed. Once the screws “H” and “L” have been tightened all the way, they must be unscrewed one turn. This must be done when the chainsaw is muffled.

Then the tool is warmed up, full throttle is given, and the first of the mentioned screws is rotated in such a way as to reach 14,000 revolutions per minute. The maximum speed should be held for 10 seconds or less.

By turning the last screw, the chain should begin to move. Then the bolt is loosened a quarter turn counterclockwise. If after that the idle speed turned out to be not so stable, and the tool accelerates slowly, the screw under the designation “L” must be turned counterclockwise, only then the chainsaw will pick up speed.

It is important to remember that the adjustment will not give results if air is sucked into the engine from the side. This can happen through:

  • accelerating pump;
  • carburetor;
  • a gasket under the carburetor;
  • crankshaft oil seals.

After completing the procedure, the instrument’s engine can be started by warming it up for 10 minutes. In this case, you can set the average speed. Then you can tackle the idle screw.

Basic adjustment step

First you need to use the rotational screws. They are wrapped clockwise all the way. Then turn it back one and a half turns.

When carburetor adjustment is required

If it happens that the adjusting screws are loosened, then the carburetor should be adjusted. Other signs may indicate the need for these manipulations, among them:

  • breakage of the protective cap;
  • significant piston wear;
  • interruptions in the operation of the motor;
  • strong vibration;
  • no response from the engine when trying to start the tool;
  • increased fuel consumption;
  • strong exhaust.

The nuances of adjusting the carburetor of the Stihl MS 250 chainsaw

You may have a question about how to adjust the carburetor on a Stihl chainsaw. First you need to decide when such a need arises. The work described may be required if the spark plug electrodes have changed color. When it turns out to be black, this indicates over-enrichment, while with a brick-gray color, you can be calm, since this is the norm. When a master notices a white bloom, then he can be sure that the mixture is depleted.

The main role in the adjustment is played by the upper screw, in the described model it is located closer to the muffler. If you follow the factory parameters, which you can find on the tool cover, then this screw must be unscrewed one turn, and then corrected. When unscrewing, the mixture will be enriched, while if the screw is screwed in, the mixture will be leaner, while less gasoline will enter the air-fuel mixture.

Idling check

You should know how to adjust the carburetor on a Chinese chainsaw. In this case, another check is carried out at idle speed. Once the acceleration adjustment has been completed, it is necessary to bring the tool to idle. If you did everything correctly, the chain will remain stationary, and the motor will pick up speed in a short time when you press the accelerator.

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You should also listen to the operation of the engine. The sound should be like a four-stroke unit. If you are thinking about how to properly tune the carburetor on your chainsaw, you must take care that the above conditions are met. If this is not the case, then the adjustment must be repeated, while the basic stage is omitted. You should not take to work if you do not have sufficient experience, because in this case, a misalignment of the unit may occur. When self-tuning is not possible, then stable work can be achieved by contacting professionals.

Additional signs

If piston wear has occurred, then it will also be necessary to repair the engine, but adjusting the carburetor will act as a temporary measure, while the unit will work more stably. If the described unit turned out to be clogged, which led to interruptions in the operation of the motor, then it will also be necessary to flush.

Whereas when a situation arises when the engine stalls or does not start, we can conclude that the working mixture was depleted. Incomplete combustion of the fuel mixture is also indicated by the abundant exhaust. This conclusion can be reached if the tool began to consume excessive amounts of fuel.

Chainsaw carburetor setting

To configure the aforementioned equipment, you do not even have to dismantle it from the chainsaw. All you need to set up is a Phillips screwdriver.

The carburetor trimming screws are located on the tool body. It is only necessary to select the correct position of the screws to ensure stable operation. In other words, in this case, the fuel mixture will be optimal for specific tasks and weather.

The entire carburetor setting can be divided into the following steps:

  • the fuel supply screw is fully tightened;
  • the fuel quality screw is fully tightened;
  • the idle screw is unscrewed (but not completely. it is not necessary for it to fall out of the bore).

After the above preparation has been completed, you can proceed directly to setting up the carburetor.

The fuel screw must be loosened 1 full turn. It is recommended to unscrew the fuel quality screw one and a half turn.

You can make sure in the future that this arrangement is considered ideal. Indeed, in fact, we are talking about the factory settings of the chainsaw, which periodically go astray due to the presence of high vibrations during operation.

How to adjust the carburetor on a Chinese chainsaw?

Contrary to popular belief, Chinese chainsaws are quite attractive from the point of view of systematic use. If you cannot afford a branded tool (a la Stihl), you can rely on a Chinese manufacturer.

In addition, inexpensive chainsaw parts can always be purchased online. That is, there will be absolutely no problems with the repair kit. The main problem with Chinese chainsaws is that they periodically have to adjust their carburetor to achieve stable and efficient operation. This is not as difficult as it seems at first glance.

Idling adjustment

After the two screws (fuel quality, fuel delivery) have been adjusted to the correct position, it is recommended to proceed to the idle setting. To do this, we tighten the idle screw one and a half turns.

Now you should start the chainsaw and carry out further idle adjustments directly with the engine running. Following the above methodology, you are guaranteed to rebuild the instrument (bring it to perfect functioning).

In the video, the master clearly demonstrates how he sets up a Chinese chainsaw:

Chainsaw carburetor 4500-5200 series

Manufacturer: ChinaModel: Code. 0194

Carburetor for chainsaw 4500-5200 series. The purpose of the carburetor is, first of all, the correct composition of the proportion of fuel with air and converting them into a fuel mixture. The carburetor has adjusting jets that regulate idle speed and fuel supply. Also in the carburetor of the chainsaw there is an air and throttle valve. The carburetor fits all Chinese chainsaws with cylinder size. piston group 43 mm and 45 mm.

How to replace the carburetor on a 4500-5200 chainsaw.

You can replace the carburetor on a chainsaw yourself without using special tools.

  • remove the filter cover
  • take out the air filter
  • disconnect the throttle and choke lever
  • disconnect the fuel hoses from the carburetor
  • there are two fastening bolts under the knee of the air filter, which must be unscrewed
  • then remove the carburetor from the seat

In order to install the carburetor on the chainsaw, do all these steps in reverse order.

How to adjust the carburetor on a chainsaw. Carburettor adjustment is a very difficult process and is best left to a specialist. Since after adjustment you will violate the factory settings of the chainsaw.

Dimensions:

  • Dimensions. 65x50x29 mm.
  • Chamber diameter. 16 mm.
  • Center mount size. 31 mm.

Difficult replacement of a piston on a Chinese chainsaw Photo report

How to repair the cylinder block of a chainsaw?

For restoration, the master completely disassembles the motor and examines its working parts. Measurements are made that allow you to accurately assess the condition of the equipment and understand what repair procedures need to be performed. During major repairs, boring of parts is possible if they are made of suitable materials.

Also, the recovery process includes other stages:

  • evaluation of the efficiency of the piston stroke, measurement of the generated compression in the working chamber;
  • checking the integrity of the equipment, searching for mechanical damage, scratches;
  • analysis of the condition of the piston fasteners, elimination of backlash and other problems;
  • inspection of other equipment that affects the operation of the piston group.

In order for the restoration of the chainsaw cylinder to be successful, the master conducts a series of checks after assembling the equipment

It is important that the power corresponds to the factory parameters, and during idle work and under load, the saw demonstrates stable rpm. Only after such checks can the equipment repair be considered complete

Why motor parts break?

Breakdowns can be planned and emergency. The planned failure depends on the manufacturer, the materials of the group, the intensity of operation. Usually, the saw resource is calculated in engine hours. After working out the prescribed number of engine hours, the tool should be returned for repair to prevent the engine.

Causes of unexpected piston breakdowns:

  • operation at increased loads, incomparable with the power of the tool;
  • lack of normal maintenance, which leads to dry operation of the motor and increased wear;
  • the use of low-quality fuel, which does not provide stable engine operation;
  • large age of the saw, despite the low intensity of use.

Each start of the tool puts a certain stress on the piston and cylinder. Therefore, the resource of the device also depends on the number of starts. If you notice extraneous sounds from the motor, a decrease in power, an increase in consumption, it’s time to return the equipment for preventive repair to a service center.

How to increase the life of your chainsaw

You need to have a pair of tires and at least four chains in stock. For a uniform wear process, the chain must be turned 180 ° after three hours of operation, after the same period of time, the chain must be replaced with another.

Timely cleaning of the tool ensures that the various holes are not clogged, which can lead to difficulty or even stop the flow of the fuel mixture, which will affect the working condition of the chainsaw.

If you are not confident in your abilities and are afraid to spoil the unit, then it is better to contact the professionals. They, by virtue of their experience, will always be able to correctly diagnose the problem and qualitatively fix problems in your chainsaw.

How to properly run a chainsaw. the main threats

What is, in fact, the problem of many councils. Let’s figure it out in order.

P / p No.Meeting councilArguments for”Arguments against”
oneThe chainsaw must be run in at idle speed.Lowest idle.The most harmful advice I come across. A great way to kill a cylinder / piston group. Idling, even in cars, is allowed only for a short time: in this mode, the fuel burns out not in optimal proportion, the possibility of lubricating surfaces sharply deteriorates, heat dissipation deteriorates sharply, carbon deposits appear, and in long-term operation, seizures occur.
2For the chainsaw, you need to prepare a special mixture of oil and gasoline. In a special proportion (some sites write. more oil, some. more gasoline).Arguments “For” are offered by both. What exactly to stop at is up to the one who listens to the advice of “experts”.Deviation from the instructions of the instructions developed by the manufacturer entails inevitable problems either from oil starvation or from an overabundance of lubricant. In either case, nothing good will come of it.
3It is necessary to carefully study the instructions, prepare a mixture, pour oil into a container for lubricating the chain and work carefully.“For”. because it is recommended by the manufacturer.There are no arguments against. But why do many sites chew this banality for a dozen paragraphs? To make the article voluminous?
fourUsing the adjusting screw “H” you need to lower the minimum speed of the chainsaw and make the mixture richer.Low rpm improves surface lubricity. This is recommended by the “leading saw manufacturers”.It’s a lie. No manufacturer will recommend pouring oil into their saw, thereby trying to shift the imperfection of their own production onto the shoulders of the consumer.

There are other options for advice. Don’t list everything.