Adjusting the carburetor of a Makita chainsaw with your own hands. How to adjust the carburetor on a chainsaw - all the secrets of the correct settings

A carburetor such as we will consider is installed on many saws of similar brands such as Poulan, Mc Culloch, Max Cut, CHAMPION

We unscrew all three screws (as shown on the indicators) and remove the top cover of this saw from the body.

We remove the air filter from our housing (shown in the figure) - a filtering foam rubber element (green foam rubber in the figure).

Unscrew two nuts at once and remove the air filter housing itself.

In order to remove this air filter housing, it is simply not enough to simply remove it from two bolts. He won't take off. The protrusion indicated on the arrow will interfere with it.
You need to apply very little upward force to the filter housing, until the protrusion is slightly higher than the very top edge of the chainsaw housing, and remove it.

We work on the right side of the carburetor. Filming fuel hose(as on the top arrow) and then the air damper drive rod.

Finally, we remove the carburetor and remove the tip of this cable from the throttle valve drive lever.

On our left side we also pull the gasoline hose together from the carburetor fitting.

The carburetor is now removed and ready for further disassembly.

In the example we are considering - a chainsaw, confusingly, that is, there is no gasoline in the gas tank. Therefore, when we removed the gas hose from right side This carburetor did not have any fuel coming out of the hose at all. Your tank may also be full, and therefore not much time may pass after working with the saw.
During operation, the fuel in the tank is under slight pressure, so after removing the hose from it, fuel will begin to flow out.

Prepare in advance a clothespin or clamp or an ordinary 13 nut.

We completely unscrew the idle speed screw and the screw securing the carburetor cover on top.

Then remove the top cover. This will open an area of the carburetor called - fuel pump where the blue transparent gasket is the fuel membrane.

On the left side of the carburetor, remove two screws (according to the instructions, the screws are marked L and H), first removing the spring clip from them. When assembling the carburetor, these screws cannot be mixed up; screw H has an annular groove; if it is not there, mark the screw with any one.

Remove the four screws from below and remove the very bottom carburetor cover.

Remove the needle valve assembly. For this purpose, remove the screw indicated by the arrow in the figure. Under the two-arm lever, don’t lose it, there is a small spring.

Champion chainsaw carburetor: and its adjustment

We begin the adjustment by adjusting the idle speed; to do this, rotate the T screw (LA) counterclockwise, achieving a complete stop of the chain at stable engine speeds.
Champion chainsaw carburetor design
Detailing a chainsaw carburetor

For further precise adjustment, you will need a tachometer and it is better to entrust it to specialists, especially since in most cases it may not be needed.
Adjusting the carburetor of the Patriot 4518 chainsaw
We start setting up the tool with screw L, then use screw H and finally screw T (LA).

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

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

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

We complete the adjustment by adjusting the idle speed, as already described above. The idle speed is set correctly if the engine runs smoothly at minimum speed and the chain does not rotate.
The carburetor can be considered adjusted if the engine accelerates quickly and sounds like a four-stroke at full throttle.

It is important!

As you know, the “Champion” chainsaw enjoys well-deserved popularity in our country both among construction and logging organizations, and among many owners personal plots and country cottages. This increased demand for a chainsaw is primarily due to its rather long service life and its absolute reliability in operation.

And for the Champion chainsaw to work properly, you need timely adjustment of the carburetor, which not only ensures efficient operation of the entire tool, but also significantly extends its service life.
And such adjustment can only be carried out with a properly tensioned chain and a cleaned air filter. Adjusting the carburetor of the Champion chainsaw is carried out using three screws and is carried out in two stages: with the engine turned off and while it is running. First, the screws for maximum and minimum speed when stopping the engine are turned clockwise until they stop. And then, without stopping, turn the adjusting screws 1.5 turns to reverse side.
The second stage involves adjusting the idle speed while the engine is running. But, before proceeding to the second stage, you must initially thoroughly warm up the chainsaw engine for five minutes. And then, when stopping the engine at idle, slowly turn the adjusting screw clockwise. But as soon as the chain begins to move, you must immediately begin turning the screw in the opposite direction, counterclockwise.
For an inexperienced person, performing all these manipulations to correctly adjust the carburetor can cause certain difficulties. And therefore, it is better, after all, to turn to professionals, with the help of whom the carburetor will be quickly adjusted and the “Champion” chainsaw will be able to work without interruptions. Experienced specialists will not only help you adjust the carburetor, but will also tell you how to use the Champion chainsaw correctly.

Adviсe

Determination of cutting chain wear

Before each start of work, special attention should be paid to the appropriate sharpening rules and the tension of the cutting chain. The chain tension is correct when the chain rests against the underside of the bar and can be easily turned by hand. To be able to do this, the chainsaw chain brake must be released.

A chainsaw chain requires sharpening in the following cases:

When sawdust produced when sawing wet wood looks like wood flour.

The chain enters the wood only when pressed firmly.

The cutting edge is noticeably damaged.

While sawing, the saw is pulled to the left or right. This is caused by uneven sharpening.

Timely determination and elimination of the wear level of a chainsaw chain is the key to long service life of the entire cutting set.

With your own hands

Instructions for running in chainsaws

Before using any imported chainsaw, it requires preliminary running-in. It is necessary, on the one hand, to extend the service life of the gasoline engine. During the running-in phase, the moving parts must first get used to each other, because Increased friction resistance is observed in the drive mechanism. On the other hand, during break-in you can acquire the necessary skills to work with a chainsaw. This is especially important for those who are working with a chainsaw for the first time.

For use with a chainsaw when cooking fuel mixture Use only branded oils. The brands of oil that can be used to prepare the fuel mixture are indicated in the operating instructions. Observe strictly required proportions oil and gasoline. The octane number of the gasoline used must be at least 90 (except for those cases where this is specified in the operating instructions).

Before starting the chainsaw, be sure to check the presence of oil in the chain lubrication tank. At high speeds, in the absence of chain lubrication, the chain and tire may fail. During operation, you can easily check the presence of chain lubrication. With the chainsaw running at high speeds, point the bar towards Blank sheet paper If the lubricant flows normally, a strip of oil will be visible on the sheet.

Read the instructions carefully, those sections regarding starting a hot and cold engine. The principle of starting the engine is the same in all saws. The only differences can be in the location of the saw controls (STOP button, air damper lever). Remember to check the position of the inertia brake before each start. The inertia brake must be switched off. When the inertia brake is switched off, the chain on the bar is pulled freely by hand (this operation can only be carried out while wearing work gloves).

When operating a chainsaw with the inertial brake on, the chainsaw body melts in the clutch area and the chainsaw may catch fire. Repairs required in this case will be considered non-warranty and will be carried out solely at the expense of the client.

Run-in must be done within 3-4 hours. Prohibited during break-in long time operate the chainsaw in idle mode. It is allowed to idle for 15-20 minutes with periodic gas release of the engine at intervals of 20-30 seconds. Then you need to continue running in operating mode with a light load. This involves sawing small-diameter wood with minimal effort on the part of the operator.

After running in the chainsaw, you must present it to service center for checking carburetor settings. Settings can only be made qualified specialist. After setting up, you can use the gas powered tool according to the operating instructions.

Characteristics

Technical parameters of saw chains

When choosing a chain for a chainsaw, you need to pay attention to several important characteristics:

number of links;
chain pitch;
drive link thickness;
purpose of use.

In addition, on our website you can select a chain according to your saw model through the chain saw directory.

Number of chain links. Determined by the internal teeth of the chain.

Chain pitch- the distance between three consecutive rivets, divided by two. This is a defining parameter, and depending on its value, all existing chains are divided into five groups with pitches of 1/4’’, 0.325’’, 3/8’’, 0.404’’ and 3/4’’.
The 1/4” (6.35 mm) pitch is typical for small chains installed on low-power one-handed saws.

0.325'' (8.25 mm) and 3/8'' (9.3 mm) pitch chains are the most common options. More than 80% of saws produced around the world are equipped with them.

0.404'' (10.26mm) and 3/4'' (19.05mm) pitches feature larger link chains for increased performance. For several decades they were equipped with saws Russian production, but are now installed only on powerful felling saws and harvesting equipment.

The larger the chain pitch, the larger the links that make it up and the higher its performance, but the wider the cut. To overcome the increasing cutting resistance, a more powerful saw is required. Fine pitch chains have other advantages - larger number teeth per unit length, smooth movement in the cut and, accordingly, reduced vibration, cleaner cut.

Drive link thickness. During operation, the chain slides in the groove of the bar, and this sliding should be smooth, without snagging and at the same time without unnecessary “bumpiness”. The thickness of the shank and the thickness of the groove must strictly correspond to each other, which increases the reliability of the chain fit and eliminates the possibility of it “jumping off.” Everything is provided in five standard sizes:

1.1 mm (0.043’’) for low-power saws
1.3 mm (0.050’’) household and semi-professional chains,
1.5 mm (0.058’’) powerful and productive saws,
1.6 mm (0.063'') and 2.0 mm (0.080'') highly professional saws.

Purpose of use imposes its own requirements on the circuits used. For example, if it is necessary to saw hard and contaminated wood or during demolition and construction of structures, it is better to use special carbide chains Picco Duro or Rapid Duro, which have carbide teeth or linings, giving them unsurpassed strength and durability. Some jobs simply cannot be completed without their help.

It is also known that for longitudinal sawing of wood (along the grain) it is advisable to use special chains. The main difference between longitudinal and transverse type chains is the angle of attack of the cutting links. For crosscut chains they are 25–35 degrees. At the chains for rip sawing(For example Stihl chains Picco Micro X) angles are sharper - from 5 to 15 degrees.

The use of chains inappropriate for their purpose leads to either reduced performance or increased “aggressiveness”, strong vibration and additional load on the chainsaw engine.

Additional characteristics of the chain are the profile height and cutting depth.

Profile height. Chains are available in high and low profile depending on the height of the cutting edge above the plane of the guide bar. High profile chains are usually used for professional purposes to obtain maximum performance sawing. Low-profile chains are installed on household and amateur chainsaws, because... Thanks to the increased support area of the cutting links and the reduced thickness of the cut chips, they are safer.

Depth of cut- this is the size of the gap between the upper edge of the tooth and the cut stop, which regulates the thickness of the chips. Most often, there are samples with gaps of 0.025 inches (or 0.635 mm) and 0.030 inches (or 0.762 mm), less often - with gaps up to 0.07 inches (or 1.778 mm), the latter are intended for machine felling units.

The depth of cut largely determines sawing performance. The larger the gap, the higher the performance. The downside to performance is vibration. So chains with a small cutting depth in the cut move more softly and “twitch” less. Therefore, to balance vibration and performance, cutters with a small depth of cut are often installed on a chain with a large pitch, and vice versa.

Prices / Order

PETROL TOOLS
BOSCH training 01/04/13.
Mechanical lawn mower BOSCH AHM 38C (38cm, 5 blades, smooth adjustment 7kg) Germany 0600886102	3"545.00 rub.	PC.
CHAMPION student 01/04/13
CHAINSAWS CHAMPION
Chainsaw Champion 55 -18"- 0.325-1.3-72 in case (2.4 kW; 4.95 kg, easy start) pr. China S5518	5"370.00 rub.	PC.
Chainsaw Champion 137-16" -3/8-1.3-56 (1.55 kW; 4.5 kg) pr. China S3716	3"490.00 rub.	PC.
Chainsaw Champion 341-18"-3/8-1.3-62 (1.6 kW; 5.8 kg, easy start) pr. China AC3112B8TD-40-AO	4"735.00 rub.	PC.
CHAMPION PETROL TRIMERS
Petrol trimmer CHAMPION T221 (0.5 kW, trimmer head, 4.5 kg) (PRC) T221	3"450.00 rub.	PC.
Petrol trimmer CHAMPION T266 (detachable rod, 0.75 kW, trim head + knife, steering wheel handle, weight 5 kg) made in China T266	4"730.00 rub.	PC.
Petrol trimmer CHAMPION T334FS (4-stroke 0.75 kW, 33.5 cm3, trim head + 3 blades, handlebar handle, 8 kg.) China CG335	6"950.00 rub.	PC.
Petrol trimmer CHAMPION T436 (split shaft, 1.25 kW, trim head + 3 blades, handlebar handle, 8.9 kg) China T436	5"470.00 rub.	PC.
Petrol trimmer CHAMPION T516 (1.46 kW, split shaft, trim head + 3 blades, handlebar handle, 9.5 kg) China T516	5"990.00 rub.	PC.
Electric trimmer CHAMPION ET450 (450W, lower motor, 2 lines, 1.6 mm, width 350 mm, 3kg) China YT5243	1"640.00 ruble	PC.
Electric trimmer CHAMPION ET1003A (1000 W, bent shaft, line 2.4mm, width 350mm, 4.1kg) China ET1003A	2"390.00 rub.	PC.
Electric trimmer CHAMPION ET1004A (1000 W, straight shaft, 2 lines, 2.4 mm, width 450 mm, 4 blades, 5.5 kg.) China ET1004A	3"120.00 rub.	PC.

Firms

Review of popular models

For Russia, this country of logging, forests, forest industry; great country, in which firewood procurement for the bulk of the population is constant urgent need; countries where hobbies for gardening and wood processing are becoming widespread, chainsaws are of particular importance.

Traditionally, in order to understand the features of chainsaw models, we will focus on some frequently mentioned characteristics. All household chainsaws are intended for occasional work. These are usually low-power instruments with the necessary minimum functions for a user who uses a saw occasionally and does not have professional skills in this area.

Semi-professional chainsaws are chainsaws with which you can perform any kind of work: repair and construction, felling forests. " Weakness"is the impossibility of using it for more than 8-10 hours daily. Such saws are often used as loppers in logging.

And professional chainsaws that have high power with a wide range of functionality. They are used in the form of shaft saws and can work up to 16 hours a day. Lightweight and low-power saws, convenient and simple, designed for household work and firewood preparation. Such chainsaws are sometimes used professionally by loggers for pruning branches. There are also universal chainsaws - powerful for felling forests and easy for pruning. Signs: smooth, level bottom of the car; rounded corners; shortened, flat wheel cover; tubular inclined handle; anti-vibration system.

Prolonged work with a vibrating tool can lead to some serious diseases of your joints, therefore the presence of an anti-vibration system is important for professional models- it's necessary.

Any chainsaw is equipped with a two-stroke single-cylinder carburetor engine. Early models of chainsaws were equipped with contact ignition, but now almost all manufacturers use electronic ignition, so there is no need to constantly clean the contacts and adjust the gap between them.

The air-fuel mixture to operate the engine is mixed in the carburetor. Using a special damper, you can manually lean or enrich the fuel mixture for a specific purpose - for example, for cutting hard wood.

From a working one technical condition The carburetor directly affects both the health of the engine and the performance of the chainsaw. Let's take a closer look at how a chainsaw carburetor works.

Almost all chainsaw models use an identical carburetor design. As an exception, we can name the carburetor of some very cheap Chinese chainsaw - some parts may be missing, and most of the components are made of very cheap materials.

The main components of the carburetor are:

Frame. It is made of aluminum to make the structure lighter and has a one-piece shape. The housing contains a diffuser, an inlet fitting, a pulse channel, a main screw and an idle screw, a damper that regulates the air supply, as well as other elements.
Diffuser. Located at the carburetor inlet.
Jets. Special valves through which the amount of fuel is regulated.
Spray.
Float chamber.

The principle of operation of a chainsaw carburetor

Before you adjust the carburetor on a chainsaw, you need to understand the principle by which it works.

When the engine starts, the air damper located at the bottom of the housing opens.
A vacuum is created in the air channel and float chamber caused by the stroke of the piston, as a result of which an air flow is sucked through the diffuser.
The intensity of the air flow suction is regulated by the position of the air damper.
Gasoline enters the float chamber through the inlet fitting from the gas tank.
The speed of passage of gasoline from the chamber to the diffuser is controlled by means of jets.
In the diffuser, gasoline is mixed with air.
The prepared air-fuel mixture enters the intake channels, from where it is directed into the working combustion chamber of the cylinder.

Basic carburetor malfunctions on a chainsaw

It should be understood that the dimensions of all holes are very small. Even the smallest contamination can block the flow of air or fuel, which is why filter elements are installed at the inlet ports. Unfortunately, they do not always cope with the task. The following signs indicate a malfunction of the chainsaw carburetor:

High gasoline consumption and thick smoke from the exhaust;
The engine “does not pull”;
Floating speed;
The engine starts, but stalls immediately or after a few seconds;
The engine does not start at all.
Chainsaw shoots at carburetor

All these malfunctions are a sign that the carburetor on the chainsaw is not adjusted correctly or that it is dirty. This implies the need for adjustment, cleaning or repair. Let's look at how to do this below.

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

The factory settings of the chainsaw carburetor provide optimal fuel and air suction parameters. But during operation, they can become confused due to vibration - even a ¼ turn shift in any of the screws can lead to a serious change in the parameters for preparing the air-fuel mixture and it is necessary to adjust the chainsaw carburetor.

The chainsaw carburetor is adjusted using three screws marked H (High), L (Low) and S. The last screw, depending on the brand and manufacturer, may have other names, for example T or LA.

H: is responsible for the operation of the main jet and regulates the maximum speed.
L: adjusts the position of the idle jet and allows you to set low speed.
S/T/LA: designed to regulate engine idle speed.

To know how to properly adjust the carburetor on a chainsaw, you need a technical passport - it indicates information about the angles of rotation of the adjusting screws. After this, we proceed directly to the adjustment. By the way, here you will need a screwdriver to adjust the chainsaw carburetor or a regular flat-head screwdriver:

Place the chainsaw on a flat surface, preferably a table or something similar.
IMPORTANT: The chainsaw must be positioned so that the bar points in the opposite direction. The engine must be turned off.
Using a wrench or screwdriver, unscrew the fastenings of the housing casing cover and remove it to get to the carburetor.
Remove the air filter that covers the carburetor for the chainsaw. The manufacturer may install a shock-absorbing foam insert on top of the carburetor - this must also be removed.
Now begins setting up the chainsaw carburetor. Screws L and H must be tightened until they stop. Tighten them slowly and carefully so as not to break them.
Unscrew both screws approximately 1.5 turns.
Start the engine and let it run for about 7-10 minutes so that it warms up well - you won’t be able to adjust the chainsaw’s carburetor on a cold engine.
After the engine has warmed up, set it to run at medium speed.
Slowly begin to tighten the idle screw counterclockwise. You need to turn it until the motor runs smoothly. If the engine starts to stall, you need to continue adjusting the chainsaw carburetor and gradually return the screw clockwise.

After the carburetor of a Chinese-made or any other chainsaw has been adjusted, it is necessary to “drive” the engine at different speeds.

Either the engine does not start or stalls immediately, most likely the carburetor is clogged and needs to be cleaned. How to check a chainsaw carburetor? You'll have to take it apart - otherwise it won't work.

Before cleaning the carburetor on a chainsaw, it is still recommended to check other components: air and fuel filters, spark plug and muffler. It is possible that they are clogged - it is easier to clean the filter or replace the spark plug than to clean the carburetor on a chainsaw. By the way, it is the problem with the spark plugs that is the reason why the chainsaw shoots into the carburetor - ignition too late leads to the formation of an excess of the air-fuel mixture, since it does not have time to burn completely.

If the problem persists, you will have to remove the carburetor. It's very easy to do this:

We remove the plastic back cover - it is held on by a latch or thread.
Remove the air filter.
Use a flat-head screwdriver to pry up the air rods and remove them. There can be two or three thrusts, depending on the model.
The carburetor is secured with two fasteners - they are located diagonally. You need to unscrew them.
Disconnect the gasoline hose that supplies fuel to the carburetor from the gas tank.

How to clean the carburetor on a chainsaw?

It is necessary to flush or clean the chainsaw carburetor only when it is removed and disassembled. Before cleaning, you need to prepare everything you need in advance: two screwdrivers (plus and minus), open-end wrenches, but preferably a head with attachments, clean rags, a special cleaning agent, a pump and an ultrasonic cleaner (recommended). Before you start cleaning, you need to drain all the gasoline - this is mandatory. After the remaining fuel has been drained and the entire instrument has been prepared, we proceed to cleaning:

Detach the top cover and remove it.
Carefully remove the fuel pump diaphragm.
There are spring clips on the left side of the housing. After they are disconnected, you can see screws under the brackets - these also need to be unscrewed.
Unscrew the bottom cover.
By unscrewing the screw, you gain access to the needle valve. It and the spring located under it must be carefully removed, and so as not to dull the needle.
The air damper is dismantled with a slight longitudinal force, after which the damper axis is removed.
Lastly, remove the throttle valve, lever and axle.

After the carburetor is disassembled, all parts must be laid out on a flat surface on a clean rag. Carefully inspect each part for blockage or wear. Special attention pay attention to the jets and inlet fitting. Their clogging is the main reason why gasoline does not flow into the carburetor of the chainsaw.

If any part shows that it is very worn out, it is better to immediately replace it with a new one, so that in the future you do not have to think again about how to repair a chainsaw carburetor.
Do-it-yourself cleaning of a chainsaw carburetor is done using a special detergent. You need to rinse each part well, then dry them with a lint-free cloth, or better yet. compressed air. All channels are also purged with air.

If you have an ultrasonic cleaner on hand, that's even better. Pour diesel fuel into the bath, carefully place the contaminated parts there for 5-10 minutes and after cleaning, dry them with compressed air.

Assembly is carried out in reverse order. Very important point is the installation of a needle valve - it should rotate freely in the seat. If the petal sticks, lightly press it or push it down so that it sits deeper.

After cleaning, it is strongly recommended to wait 20-24 hours to allow the cleaning agent to completely evaporate. Otherwise, it will mix with the air-fuel mixture and enter the cylinder, leaving carbon deposits on the walls after combustion.

High-quality adjustment of the chainsaw carburetor can provide effective work this tool at full power. In addition, such DIY actions allow you to use fuel more economically during work.

Misadjustment of a chainsaw is a fairly common occurrence, especially for Shtil and Ural chainsaws. The need is determined in accordance with the presence of the following signs:

Instability of motor performance. The tool may be difficult to start and stall almost immediately, or may not start at all. The root cause most often lies in the use of a fuel mixture with a low octane number.
Significant excess fuel consumption. Significant exhaust emissions and incomplete fuel consumption may occur. This situation is typical for the use of highly oversaturated mixtures in Stihl saws.
Defects or fluctuations in the coating over the protective caps of the adjusting screws. Such a violation is extremely rare and occurs as a result of inept handling of the adjusting parts.
Severe piston wear, which can be corrected briefly by adjustment, but requires overhaul chainsaw engine.
Karuburator blockages of varying degrees caused by the use of low-quality gasoline, as well as malfunctions of the air filter or the ingress of scale. Such a violation requires adjustment in conjunction with high-quality washing.

Features of do-it-yourself adjustment

The adjustment occurs in two stages.

First setup– basic (factory), carried out with the engine turned off.
Final– performed with the engine running and fully warmed up. For precise definition values of rotation angles, especially in the Ural chainsaw, it is necessary to use the data from the operating instructions for the specific tool.

The adjustment is performed using clean fuel and air filters. Most carburetors are adjusted using three screws: maximum and minimum speed, as well as idle speed.

L– used for low-speed settings;
H– allows you to tune at high speeds;
T– belongs to the visible category and regulates idle movement.

Husqvarna chainsaw carburetor

On initial stage it is necessary to find the highest speed at zero load, which is done by slowly turning bolt L.
Next, the screw is turned a quarter turn in a counterclockwise direction. When the chain rotates at idle speed, it is necessary to adjust the T element in a counterclockwise direction until the chain stops, which you can sharpen yourself, following the instructions and tips available.
Screw H is responsible for power and speed indicators. Using a lean mixture during the adjustment process can cause excessive speed, which can lead to damage to the saw.
Warming up the motor of the Husqvarna instrument full speed ahead is done within a few seconds. Screw H is then adjusted by turning it a quarter turn in a counterclockwise direction. All results must be checked with a tachometer and comply with the passport documentation for Husqvarna equipment.
Precise adjustment of the idle speed of the T screw is possible after adjusting the fastening components L and H. To adjust the idle speed, the T part should be adjusted while the engine is running. Rotation is carried out in the standard direction (along the direction) until the chain begins to rotate. Then the screw is turned counterclockwise until the chain stops completely.

Chainsaw carburetors Partner, Shtil and Ural

Setting up the carburetors of these tools can be done independently only if you have certain knowledge and a tachometer. Otherwise, instrument adjustments should be carried out by professional mechanics.

The manufacturer adjusts the carburetor for optimal operating conditions. The consumer is given the opportunity to make corrective adjustments, the need for which arises quite rarely.

If in the process of adjusting chainsaws of the Partner, Shtil and Ural brands, fuel that differs high-quality composition from the standard, adjustment is performed with screws L and H. To lower the octane number of gasoline and increase the speed, you need to turn the screws from left to right. To increase the octane number, you should set the speed to low and turn the screws from right to left.

High-quality debugging of the carburetor of chainsaws Partner, Shtil and Ural implies the implementation following conditions:

fine tuning work is carried out exclusively under hot engine conditions with a minimum working time of ten minutes;
adjustment is made only with a clean air filter;
The rotating chain is stopped by using the adjusting screw from left to right until it stops completely.

When performing adjustment work, you must follow safety precautions and hold the chainsaw chain away from you. To set up a Ural brand tool, it is recommended to use the services of professionals.

Checking the operation of a Husqvar chainsaw

A properly adjusted carburetor is characterized by slow acceleration of the “engine” and noise characteristic of a four-stroke engine under full throttle conditions.

Screw adjustment using a mixture that is too lean causes difficult starting and poor engine acceleration.

Correct idle speed is characterized by uniform operation of the engine in all positions with a sufficient circulating supply during the rotation of the chain.

The sound of a properly running engine is similar to a four-stroke one. A lean mixture causes the chainsaw to squeal, and when using an overly rich mixture, the muffler smokes.

The carburetor of each chainsaw has three adjusting screws: for the jet - low speed, for the jet - high speed and a screw for idle speed.

The adjustment components H and L adjust the balance between the fuel and lubricant mixture and air masses, which is determined during the process of opening the throttle valve. Screw tightening in a clockwise direction contributes to the leanness of the mixture and the formation of low speeds. Screw unscrewing in a counterclockwise direction causes mixture enrichment and an increase in speed.

Operation without load of a chainsaw, the rules for choosing which we have already described in one of our previous publications , is brought to the required state by screw T. Using it in a clockwise direction helps to increase the speed, and turning the bolt counterclockwise allows you to reduce speed.

All chainsaws undergo the basic type of carburetor tuning. Such manipulations must be carried out in the factory during testing. It is typical to adjust the carburetor to operate at a richer temperature than optimal type mixtures. Such indicators must be maintained during the first hours of operation of the chainsaw. Next, you need to fine-tune the carburetor system. You should pay special attention to the precise settings of Ural chainsaws.

The exact type of adjustment involves using the T screw counterclockwise while rotating at idle speed chains. Screw rotation stops when the chain comes to a complete stop. It is advisable to perform fine adjustments yourself when using special equipment under hot conditions.

Repairing a Stihl chainsaw carburetor (video)

A chainsaw is an indispensable tool in private households. Therefore, its smooth functioning is very important. The high-quality operation of a chainsaw largely depends on how effectively the carburetor performs its functions. Let's try to figure out how to adjust the carburetor on a chainsaw yourself.

Design and principle of operation of a chainsaw carburetor

As with any other mechanism, before doing anything, you need to understand its structure and operating principle. So, the carburetor is the part of the engine designed for mixing oxygen and fuel in certain proportions, and supplying this mixture to the engine. Violation of the proportions leads to poor engine performance or excessive fuel consumption, or to its complete stop.

The carburetor design is, in general, the same in all saws, with the exception of Chinese-made chainsaws. But, in principle, it would not be superfluous to look at the instrument’s data sheet and study the structure of the carburetor. Its main components are:

tube - an element responsible for portioned air supply by opening or closing the damper;
diffuser - an element located at the inlet through which fuel is supplied and designed to accelerate air flow;
atomizer - a mechanism for injecting fuel into the air flow;
float chamber - a cavity designed to maintain combustible mixture on the same level. It is from this that the fuel enters the atomizer through the nozzle.

During carburetor operation, air enters the tube and flows through it at a speed controlled by the damper. Opening the tube activates the float. Air flow passing through the diffuser, mixed with fuel and sprayed. The resulting mixture enters the cylinder through the inlet port. The pressure in the chamber with the float is close to atmospheric, and in the air tube the pressure is rarefied. This difference in pressure is needed to suck fuel into the tube. The more fuel supplied, the higher the engine speed. That's how it is general structure and the operating principle of a chainsaw carburetor.

Signs that indicate the need for carburetor adjustment

There are several signs that the carburetor is not working properly and needs to be adjusted.

If you have some of the symptoms described above, then it’s time to start adjusting the chainsaw carburetor.

Preparing for adjustment

The chainsaw carburetor is adjusted using three screws:

“H” - screw that regulates maximum speed and main jet;
“L” - screw for setting low engine speeds and idle jet;
the third screw adjusts the idle speed and can be designated differently: “LA”, “S”, “T”.

It is also possible that your chainsaw will have fewer screws, depending on the manufacturer.

So, we have found out the designation of the screws, let's move on to preparatory procedures. Everything is simple here.

Now you can proceed directly to the adjustment itself, which is carried out in two stages.

Adjusting the carburetor of chainsaws

In principle, setting up a chainsaw carburetor is quite simple if you have experience or related skills. The first thing to do is move slowly tighten the screws clockwise, marked L and H all the way. And then unscrew them back one and a half turns. All this is done with the engine turned off.

Having completed the procedure, start the engine and warm it up for 10 minutes, setting it to medium speed. Now let's move on to the idle speed screw, which, as we remember, can be designated differently. It's necessary screw counterclockwise until the motor starts running smoothly. Watch whether the chain moves or does not move. If yes, then the screw needs to be turned counterclockwise. If the engine stalls in this mode, turn the screw slightly clockwise.

Upon completion of all manipulations, be sure to check: acceleration, idle speed and speed.

Checking the operation of the chainsaw after adjusting the carburetor

The following tests will show whether you have adjusted the carburetor on your chainsaw correctly. Gently press the accelerator and if the engine speed almost immediately increases to maximum, then it is working normally when accelerating. By maximum we mean values from 2800 to 15000. If this does not happen, turn screw L one-eighth of a turn counterclockwise.

Maximum number of motor rotations per minute should be between 11500 – 15000. If the speed exceeds these values, the ignition process will be disrupted. Therefore, we check how the ignition occurs; if there are any malfunctions, turn screw H counterclockwise, thereby reducing the number of revolutions per minute.

After these tests, you need to check the operation of the chainsaw in idle mode. We can talk about correct adjustment of the idle speed screw if, when checking, the chain does not move, and the engine quickly accelerates when you press the accelerator maximum amount rpm The sound of the engine should come in four strokes.

Carburetor adjustment do it yourself with a chainsaw

How to adjust the carburetor of chainsaw

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Basic carburetor adjustment.

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

Checking and adjusting idle speed.

Finding the highest revolutions idle move, to do this, slowly turn screw L in different directions. After finding the position of the highest engine speed, turn screw L 1/4 turn counterclockwise. If the chain rotates at idle, screw T or (S) should be turned counterclockwise until it stops.

Checking and adjusting the maximum speed.

The maximum number of revolutions is changed using screw H. When it is turned in (clockwise rotation), the speed increases, and when turned out, it decreases. Chainsaw engines have the highest rotation speed from 11,500 rpm. up to 15000 rpm. A higher speed is not ensured by the ignition, in addition, it becomes dangerous for the engine. Limit speeds can be determined by interruptions in ignition. If they advance, screw H is turned slightly against clockwise.

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

When you smoothly press the gas trigger, the engine should confidently and quickly pick up speed from idle to maximum (from 2800 rev. to 11500-15000 rev., depending on the unit). If the speed is gained slowly, with a delay, screw L must be turned slowly against clockwise, but no more than 1/8 of a turn.

After adjusting the acceleration and maximum speed, you should check the operation of the saw again at idle speed - the engine should run steadily, the chain should not move. The chainsaw adjustment must be repeated if this condition is not met, except for the basic adjustment stage.