For self-tuning the carburetor, you need to familiarize yourself with its device and remember the order of work that is carried out to adjust the parts responsible for the correct functioning of the constituent elements of the device and nearby parts. It is necessary to carefully handle objects for adjusting the chainsaw system, and also to determine the correspondence of the set parameters to the maximum permissible values.
About the carburetor device
The carburetor is used to mix the combustible mixture with air in compliance with the predetermined proportions. If the exact dosages are not followed, the correct operation of the engine is compromised. When a large amount of air enters during mixing of the components, and there is not enough fuel, then such a mixture is considered “poor”.
Over-saturation should also not be allowed, since with a large amount of fuel compared to air, malfunctions or engine wear are also possible. Carburetor adjustment is necessary not only before initial use, but also when any abnormalities in its operation are detected. Before starting work with the chainsaw, do not forget to run it in.
The carburetor design contains a standard set of elements, but it may vary slightly depending on the manufacturer. Components:
- The basis... It is a special tube that visually resembles an aerodynamic structure. Air passes through it. In the transverse direction in the middle of the pipe there is a damper. Its position can be changed. The more it is pushed into the passage, the less air enters the engine.
- Diffuser... This is the tapered part of the tube. With its help, the air flow rate increases exactly in the segment from which the fuel comes out.
- Channels for fuel supply. The fuel mixture is contained in the float chamber, then passes into the nozzle, from which it flows into the sprayer.
- Float chamber... It is a separate structural element, reminiscent of the shape of a tank. Designed to constantly maintain the optimal level of the fuel fluid in front of the inlet to the air channel.
What you need to have to set up and adjust a chainsaw with your own hands
Every carburetor owner should have the necessary tools to adjust this system. There are three adjusting screws located on the body of the device. They have their own markings:
- L - screw for low rpm correction.
- H - screw for high speed adjustment.
- T - regulates the idle speed, in most cases it is used for experiments.
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).
To carry out a safe repair, you need to prepare a flat surface where you can carefully position the device, and turn the chain in the opposite direction. We need a tachometer. It determines the presence of a malfunction in the carburetor. When the screws are turning, the sound should be perfect and absolutely even. If squealing notes are noticed, then the mixture is oversaturated.
How to properly adjust a factory saw
Carburetor adjustment is divided into two main steps. The first is called basic. It is performed with the engine running. The second is performed when the engine is warm.
To carry out the carburetor tuning procedure successfully, you need to read the operating instructions in advance specific model to identify additional features of the device configuration.
First stage
The adjusting screws for the highest and lowest speed should be moved clockwise until the highest resistance is encountered. When the screws reach the stop, you need to move them in the opposite direction and leave them after 1.5 turns.
The main stage
The engine turns on at medium speed and warms up like this for about 10 minutes. The screw responsible for adjusting the idle speed must move clockwise. It is released only when the engine comes into stable operation. It is necessary to check that the chain does not move during this process.
In idle mode, the engine may stall (cause -). In this case, immediately turn the adjusting screw clockwise until it stops. Sometimes the chain starts to move. In this case, turn the adjusting screw in the opposite direction.
Checking acceleration work
A little research needs to be done. The acceleration of the device is initiated. The serviceability of the engine should be assessed during the maximum revolutions. When the engine is functioning properly it means when you press the accelerator, the speed quickly increases to 15,000 rpm.
If this does not happen or the increase in speed is too slow, you must use the screw marked with the letter L. It turns counterclockwise. Moderate movements must be observed, since the turn cannot be more than 1/8 of a full circle.
How to adjust the maximum RPM
To limit this figure, you need to use a screw marked H. To increase the number of revolutions, turn it clockwise, and to decrease them in the opposite direction. The maximum frequency should not exceed 15000 rpm.
If you increase this indicator, the engine of the device will work for wear, which will lead to problems in the ignition system. When turning this screw, the ignition processes of the device must be taken into account. If the slightest glitches appear, then the maximum speed value must be reduced.
Final check at idle
Before this procedure, it is necessary to make a full adjustment of the components of the carburetor when operating at maximum speed. Next, you should check the functioning of the device in idle cold mode. When the correct parameters are reached during the adjustment, you can see the exact conformity of the carburetor design to the following criteria:
If violations are noticed in the above parameters or the device was not completely adjusted, you need to perform the main setup step again. Sometimes actions are performed incorrectly. In this case, the device may fail due to the loss of the correct node settings. In this case, you will have to contact a specialist.
Dismantling the carburetor if it is necessary to check or repair components
The device of different models of carburetors is almost the same, so when working with them, you can use the standard scheme. All elements must be removed carefully, and then lay out in the order belowso that you can successfully place items in place at the end of the repair work.
- The top cover is removed. To do this, unscrew the 3 bolts holding it in a circle.
- The foam rubber is also removable, since it is the upper part of the air-conducting filter.
- The fuel hose is removed.
- The drive thrust is output directly to it.
- The cable end is disconnected.
- The petrol hose can be removed completely by pulling it off the fitting in a planned manner.
To finally prepare the carburetor for overhaul or replacement of the smallest parts, you need to carefully disconnect it from the main system... Sometimes further disassembly is required. Unscrew the components carefully and stack the fasteners in groups, as these small parts are easily lost.
How to properly adjust a Chinese-made saw - adjusting instructions
To properly configure the carburetor of a Chinese chainsaw, you must first remember the factory settings of the device, then turn on the engine. Subsequently, you will have to leave it to work for several hours in order to accurately set your own parameters. Sometimes the work is performed once after ten minutes of engine operation, but many Chinese-made models require special handling.
Adjustment procedure:
- Activities start in idle mode... With the help of the adjusting screws, you need to achieve a systematic set of revolutions by the engine, so you should first let it run at low speeds. The deviation from the norm is the movement of the chain along the tire. In this case, the end screws must be adjusted to the optimal position so that the chain remains stationary.
- Transition to average speed... Sometimes the engine will smoke. This defect can be eliminated by tightening the screw to supply a leaner fuel mixture.
In this case, the smoke will disappear, but the engine speed will increase. It is necessary to adjust the settings until the level is reached when, when you press the throttle, the engine smoothly picks up speed, no sudden jerks or interruptions are heard.
- Device motor is being checked... The chainsaw is moved to minimum speed, and then the lever is rapidly pressed. At maximum pressure, it is held for 3 seconds. If there is a malfunction of the engine, gradually loosen the screw until the optimum position is reached.
- The chainsaw should run for several hours under real conditions... It is necessary to engage in sawing wood, and then inspect all the elements involved in this event. If there are deviations, they must be corrected using adjusting devices. When all defects have been eliminated and optimal settings have been established for supplying correctly concentrated fuel, the process of setting up the device can be considered complete.
Before buying, we recommend that you familiarize yourself with the rating of chainsaws for reliability and quality.
Look clearly at the video:
Conclusion
In order for the chainsaw to work properly, you need to carefully perform work on adjusting the carburetor in exact accordance with their sequence. If there are any irregularities in the functioning of the device, it is necessary to completely disassemble it yourself. In most cases, it is necessary to replace any parts that have become unusable.
With a constant check of the quality of the carburetor settings and the implementation of timely actions to improve its operation, problems with the chainsaw do not arise.
A chainsaw is a tool equipped with a two-stroke engine that requires carburetor adjustment from time to time to function properly. Standard or factory adjustment and tuning of the chainsaw carburetor is carried out in production, during the assembly of the tool. However, for stable operation and good performance, it is necessary to adjust the carburetor of the chainsaw during break-in.
After and during the break-in process, the owner's task is to properly adjust the carburetor for the most efficient, safe and durable operation of the chainsaw engine.
Do-it-yourself chainsaw carburetor adjustment - video using the Husqvarna saw as an example:
The main reasons for adjusting the carburetor of the chainsaw:
- gasoline consumption has increased, the device consumes too much oil;
- during operation, the chainsaw heats up very much, smokes, makes popping or explosive sounds (such a problem is a signal that you need to clean the muffler, blow the breather, rinse the jets in acetone);
- the engine stopped idling;
- the chainsaw begins to stall some time after work, in general, the tool has become worse to work - it does not develop power so effectively, does not develop maximum speed;
- the chainsaw vibrates strongly during operation;
- it is also necessary to adjust the carburetor if the chainsaw has previously operated on low-quality fuel or an improperly prepared fuel mixture.
Chainsaw carburetor setting:
What tool is needed to adjust the carburetor
To set up and adjust the carburetor, the following tools are used:
- tachometer (a special device for adjusting the carburetor, with its help the owner of the chainsaw can determine what is the maximum number of engine revolutions for a given model, and then make a correction according to the manufacturer's recommendations);
- an adjusting key (a special tool, which is often available only in service centers, is not supplied with chainsaws, since it can be used by inexperienced users, which will not lead to tuning, but to a chainsaw breakdown).
Note: setting and adjusting the carburetor of a chainsaw of any model, as well as its repair, should be carried out only by specialists of the service center while the tool is under warranty.
Independent attempts to clean the carburetor, flush and eliminate existing faults may not give the desired result.
Overview of tools for adjusting the operation and repair of the chainsaw carburetor:
Theory and principles of the fuel system, carburetor design
How the carburetor works
In different models of chainsaws, the structural arrangement of the carburetor may differ, however, the principle of operation of this part is always the same: the forced air flow moves in the direction of the air (pulse) channel, the air is regulated by the air damper. Air entering the impulse channel changes its speed. The speed change is influenced by a special valve that closes the air inlet. Fuel is supplied to the air duct and mixed with the air flow. As a result, a combustible fuel-air mixture is formed, which then enters the engine and burns there.
Figure 1. Diagram of the principle of operation of the chainsaw carburetor
Diagram of the principle of operation of a chainsaw carburetor
Figure 2. Husqvarna 137 chainsaw carburetor
Figure 3. The principle of operation of the fuel system on the example of the carburetor of a chainsaw with a two-stroke engine
The principle of operation of the fuel system on the example of the carburetor of a chainsaw with a two-stroke engine
The main task of the carburetor is the continuous and high-quality operation of the engine.
Components of any carburetor are:
- aluminum body (one-piece, cast);
- jets or valves that regulate the amount of fuel entering the carburetor;
- float chamber;
- diffuser;
- spray.
On picture 1 you can see the location of the key carburetor nodes, and in Figure 2 you can see the appearance of the chainsaw carburetor. To correctly adjust the carburetor, the owner of the chainsaw should know on what principle this part works:
- when the engine starts, the air damper opens;
- due to the piston stroke, rarefied air is formed inside the float chamber and in the air channel;
- then the mass of air is sucked in through the diffuser, where it mixes with the fuel that also passed through the nozzle into the float chamber, this is how the fuel-air mixture comes into the inlet channels;
- the last stage is the mixture entering the engine combustion chamber.
By adjusting the position of the throttle, the owner of the chainsaw can either add air to the fuel or deplete it - this means that the fuel mixture will enter the combustion chamber faster or slower. The carburetor adjusting screws are used to adjust the engine speed. An air filter is installed above the carburetor, which cleans the air before it enters the air channel.
A video in which a table is presented for adjusting the carburetor of a Husqvarna chainsaw:
Figure 4. Table of proportions of the oil-fuel mixture for Husqvarna chainsaws
Table of proportions of oil-fuel mixture for Husqvarna chainsaws
Step by step sequence of the adjustment process
Before proceeding with the adjustment, remember:
- adjustment is carried out only "hot", that is, the engine must be started and warmed up for 10 minutes;
- then the adjusting screw is turned counterclockwise and the chain of the chainsaw is stopped;
- before adjusting the chainsaw, you need to put it on a flat surface, and direct the saw part away from the owner;
- for adjustment, three screws with letter designations are used, H - adjusts the upper speed, controls the main jet, L - adjusts the idle jet, adjusts low speed, T - adjusts the idle speed.
Adjusting the carburetor step by step:
- turn the screw L from left to right, or from right to left, find the maximum engine speed, then go back 1/4 of a turn;
- do the same with the screw H;
- the chainsaw should run for a few seconds, using a tachometer, determine the maximum engine speed - their indicator should not exceed the maximum specified in the instructions for the chainsaw;
- if in idle mode the chain moves, turn screw T in the direction of chain movement until the chain stops completely (idle speed is always controlled only by screw T, which is turned from right to left - counterclockwise - until the chain stops completely).
If the carburetor is adjusted correctly, the engine will accelerate quickly, the engine sound will be clear and rhythmic, and the chain will not idle.
Why can adjustments be ineffective?
- the threaded fasteners are weakened, air penetrates through the gap;
- the jets are clogged with resinous deposits, rinsing in acetone is required;
- the ignition is not adjusted.
Features of setting up Chinese chainsaws
Chinese chainsaws, especially newer models, may have some nuances in carburetor settings. Here are the main features:
- to adjust the carburetor of a Chinese chainsaw, you first need to set the idle mode so that the chain does not move along the tire;
- in the medium speed mode, a smoky exhaust may appear, it is removed by turning the lean mixture screw;
- the maximum number of revolutions of the chainsaw engine must not be exceeded (use a tachometer);
- if you adjusted the carburetor on a Chinese chainsaw correctly, when the gas is reset to a minimum, the device will not stall, and it will also quickly develop speed.
Video on adjusting the carburetor of a Chinese chainsaw
Video about adjusting and adjusting the chainsaw carburetor
The internal combustion engine works by burning a premixed mixture of air, oil and gasoline. Chainsaw carburetor adjustment is needed to prepare the mixture in the required proportion. It depends on the operation of the carburetor whether the engine will run at the declared power or stall.
Regardless of the manufacturer, the principle and procedure for the carburetor of internal combustion engines is the same. For mixing air and fuel, the carburetor is a device that includes:
- constricted air tube;
- fuel supply system;
- regulating air damper.
Air under atmospheric pressure, passing through the air cleaner, is supplied to the narrowing zone, where its flow rate is regulated by a flat damper overlapping the cross-section. After constriction, a vacuum occurs in the pipe. As a result, the vacuum sucks in fuel from the fuel supply tube, the exit from which is regulated by a fuel needle connected to the float chamber by a jet. The device of a chainsaw carburetor is, in principle, no different from other fuel mixers of internal combustion engines.
The mixing principle is to regulate the air damper, float level, depending on the degree of vacuum. We open the air - more fuel comes in, the engine rises. The correct combustion ratio depends on the precise adjustment of the chainsaw carburetor. If there is a lot of air in the fuel, the power drops, the mixture is called lean. With a lack of air, there is a large fuel consumption, incomplete combustion, carbon deposits on the cylinder and exhaust of unburned fuel. This says the mixture is oversaturated.
According to the instructions, it requires running-in with the use of an enriched fuel mixture. Therefore, the carburetor comes from the factory with the setting for the run-in period. When switching to the operating mode, the node is reconfigured.
Signs of good chainsaw carburetor performance:
- the engine runs smoothly, sounding like a four-stroke;
- fast set of revolutions;
- the chain does not spin when idling.
When carburetor adjustment is required
The new chainsaw is adjusted to the recommended mix. All you need is fine tuning with three screws; you don't need to disassemble the carburetor. The purpose of the adjusting screws:
- "L" regulates the fuel supply at low rpm;
- "H" is needed to regulate the maximum fuel supply;
- "T" idle speed control.
Since the adjustment of the saw carburetor takes place by ear with the engine running, safety precautions must be observed. The saw should be positioned securely with the cutters pointed in a safe direction.
Before starting the manipulation, it is necessary to mark the initial position of the screws with paint or felt-tip pen. The exact values \u200b\u200bfor setting the carburetor of the chainsaw for each model are in the instruction manual.
However, more often, a carburetor tincture is required after eliminating a tool malfunction. The reasons may be:
- violation of the protective cap and imbalance of the screws;
- engine piston wear, requiring a different mixture to work;
- unsatisfactory operation of the carburetor itself.
How do I adjust the carburetor on a particular model? Perform operations sequentially, guided by the instructions. Here is the algorithm, the general sequence of actions.
There are two stages of tuning:
- basic, with the engine off;
- thin - on a warm engine, idling.
The basic setting is only for the low and high speed fuel screws. Smoothly, without haste, you should completely close the flaps to the stop. Also slowly open both screws counterclockwise 1.5 turns. Then start the engine and warm it up for 10 minutes.
How to adjust the carburetor on a chainsaw with the engine running:
- adjust the idle speed with the screw "T", turning counterclockwise until the engine runs at idle speed;
- check the speed of the set of revolutions, with slow unwinding, turn the screw L an additional 1/8 turn;
- set the highest rotation speed on the tachometer with screw H;
- check the operation of the carburetor at idle speed completely.
How to find a faulty carburetor
However, the adjustment may be preceded by the repair of the carburetor itself, when it cannot fulfill its function as a fuel mixer.
If fuel for some reason does not enter the engine, check the condition of the fuel supply unit. Often the reason is the supply of low-quality gasoline, as a result, the fuel passages are clogged.
If the fuel mixture has stood for a long time, the additives have collapsed, the mixture can clog the passages and grate with sediment. In this case, a lengthy flushing is required, which is done with solvents in a service workshop.
Troubleshooting yourself
If the troubleshooting is done by hand, it is necessary to free up space and expand the small parts. Tool required:
- brush;
- screwdriver for cross-threaded heads;
- socket wrench or head M6;
- pure gasoline.
The main thing is to properly release the unit from the installation site, cleaning it from the outside from dirt. The air intake is removed, opening access to the carburetor and the suction draft. Remove the throttle lever by lowering the carburetor choke. Release the part by removing the choke lever, lifting the wire along with the lever towards you, picking it up on the left.
Rinse the freed carburetor in gasoline, blow out with air, clean the grate by injecting it with a thin needle.
When reassembling the assembly, make sure that the spring under the needle arm is in place. If you forget it, the fuel is not cut off, the candle is damp and does not give a spark.
It happens that the gas key slightly wedges. In this case, the throttle must be cleaned of plaque. It is necessary to protect the damper with tinning after cleaning.
After assembling the carburetor, setting it in place, adjust it as described above.
Video instruction for adjusting the chainsaw carburetor
Why might it be necessary to adjust the carburetor even if it seems to start and work? Carburetor adjustments should be optimal.
In general, the carburetor has a very important effect on the operation of the chainsaw, it is its "brain" indicating how much air and fuel mixture to supply to the cylinder and in what proportion. If the mixture is "rich", that is, there will be more fuel in it, then as a result we have a loss of power, deposits on the cylinder walls and piston. Which in turn can lead to the failure of the chainsaw. In turn, the "lean" mixture, which has more than the norm in its air composition, also leads to power loss, insufficient lubrication of the CPG, scuffing and possible "jamming" of the engine. Optimal settings of the chainsaw carburetor allows you to get maximum power, extend the engine life, and ensure minimum emissions!
Poor and rich mix
A little more about the "lean" and "rich" mixtures.
A "rich" mixture is a fuel mixture in which the amount of fuel supplied to the carburetor exceeds the norm. In this case, the fuel does not have time to burn completely and less energy is produced than with the optimal fuel-to-air ratio. Partially unused fuel gets into the muffler, then the chainsaw gives off a lot of smoke.
There is an excess of air in the "lean" mixture, which is not good either, since it has its drawbacks. Namely: insufficient energy in the flash (which means a loss of power as a result), excessive heating of the cylinder due to insufficient lubrication and high rpm, which leads to scuffing, and there it is not far to "jam" the engine.
Chainsaw carburetor adjustment
Most chainsaws have three adjusting screws on the carburetor. In order about each:
- T - Idling screw. The idle screw is responsible for the position of the throttle valve when the throttle handle is fully released. If the throttle valve is not open enough, the engine will stall when the handle is released, as the valve will cut off the fuel mixture supply. In the event that the throttle valve is opened to a larger value than it should be, then the chain will rotate, which is strictly prohibited by safety precautions when working with a chainsaw.
- L-screw for adjusting low speed.This screw adjusts the amount of fuel in the fuel mixture when the chainsaw is idling. If the amount of fuel is large, then the engine will stall under load, if there is not enough fuel, then the result is engine overheating, seizures, and so on ...
- H-High speed adjustment screw.Responsible for the amount of fuel in the mixture when the chainsaw is running. If this adjustment is set for a larger amount of fuel, then the engine works "inappropriately" and smokes, and if it is for less, then we get too high revolutions and overheating.
Adjusting the carburetor step by step
- We check the condition of the air filter. We remove it and either clean it or change it. If the air filter is clogged with dirt and sawdust, the chainsaw will not work normally.
- We check the condition of the muffler. It should be clean and unforgotten. Learn more about muffler cleaning.
- Before you start adjusting the carburetor, you should fill the fuel tank at least half way.
- If the chainsaw is capable of starting, then let it run for a few minutes to warm it up. If the adjustment is carried out "cold", then the mixture will be re-enriched after warming up.
- It is necessary to start the adjustment by adjusting the idle speed - screw L. It is highly desirable to have a tachometer, then we focus on 2700 rpm. If not, then we need to find the highest idle rpm. In this case, the chain should not rotate !!! If it still turns (the chain, of course, not the Earth), then we achieve its stop by rotating the screw T. The sound of the chainsaw should be like listening to the file below.
The chainsaw is an indispensable tool, both in the home garden and in the summer cottage. But even the most reliable "iron" assistant begins to mope, then it does not start, then it stalls. There can be many reasons, both related to the quality of the fuel mixture and to the engine.
There are a lot of nuances, we will not consider all of them in this article. And we will "take a closer look" at that part of the engine, which is called the carburetor. And we will try to find the answer to the following questions: when is it necessary to adjust the carburetor of the chainsaw and, in fact, what is the scheme of such an adjustment.
Chainsaw carburetor device
Before proceeding with the adjustment, you need to know the structure and principle of operation of the carburetor. This will help to avoid many "complications". So, to begin with, let's recall the principle of operation of an internal combustion engine. The cylinder contains fuel, and when burned, a small "explosion" is created which creates a lot of pressure. This pressure pushes the piston, the piston, when set in motion, rotates the crankshaft. Ultimately, the pressure energy is converted into torque, which drives the chain through the sprocket.
During normal operation of the engine, it burns up to 10 milligrams of fuel in each cycle. And the fuel mixture is prepared and supplied in the carburetor.
Thus, the purpose of the carburetor is to mix the combustible mixture with air in the required proportions. If these proportions are violated, engine operation is disrupted. For example, when mixing little fuel comes in, and on the contrary a lot of air, then such a mixture is called "lean". Conversely, if there is not enough air, but on the contrary there is a lot of fuel, then this is a supersaturated mixture. Both cases lead to malfunctions in the normal operation of the engine and require adjustment.
The carburetor consists of the following basic elements, and although the design may differ depending on the model, the design and principle of operation are approximately the same:
- the base of the carburetor is a tube, which in its characteristics resembles a wind tunnel, an air flow enters through it; - an air damper is located across the tube, its position either increases the air flow or decreases it;
- the tube has a constriction - a diffuser, which increases the speed of the air flow just in the place where the hole for the fuel supply is located;
- the fuel itself enters the air channel from the atomizer, into which it enters through the nozzle from the float chamber (in the photo it is indicated as a fuel needle);
- the float chamber itself serves as a kind of reservoir, the purpose of which is to ensure a constant level of fuel at the entrance to the air channel.
The principle of operation of the carburetor is as follows. A fast air stream flows through the air channel, its speed will also depend on the position of the damper. The float level ensures the degree of opening of the fuel supply channel and depends on the position of the same air damper. The air flow passing through the diffuser picks up the incoming fuel and sprays it. At this moment, a mixture is formed, which is sucked through the intake pipe into the cylinder.
In the float chamber, the pressure level is approximately equal to atmospheric, but in the air channel it is rarefied. Due to the pressure difference, the fuel is sucked through the nozzle into the air duct. The more the air damper is open, the greater the air flow, and, accordingly, more fuel comes in. More fuel - the engine speed increases.
This is how the carburetor works. There may be nuances in its structure, but knowing how the simplest carburetor works, you can always understand and determine the purpose of other elements.
When is adjustment necessary
In general, the need to adjust the carburetor of a Stihl chainsaw, or any other brand, arises quite rarely. Signs of a misaligned carburetor are indicated by:
- the engine starts and stalls, or does not start - in this case, the cause may be a "poor" fuel mixture;
- fuel consumption has increased significantly and the amount of exhaust gases has increased (the fuel does not completely burn out) - the cause may be an oversaturated mixture.
The adjustment itself gets lost in very rare cases, namely:
- when the fixation of the adjusting screws was broken, there are three of them. Vibration or damage to the protective cap may be the cause. It is quite rare that the screws have not been touched.
- in case of significant engine wear, namely piston. Then the factory settings are not suitable. In this case, adjusting the carburetor of the Patriot chainsaw, or another model, can save the situation for a while. But here it is just right to think more about repairing the engine, rather than adjusting the carburetor of the Husqvarna chainsaw or the like;
- the reason may be due to the formation of a blockage in the carburetor, the cause may be poor quality gasoline, damage to the air filter or scale. In this option, in addition to adjustment, disassembly and flushing of the carburetor is necessary.
Chainsaw carburetor adjustment
Although quite rare, carburetor adjustments may still be required. Immediately, we note that not everything can be done independently, unless you have a tachometer and at least once see with your own eyes how to do it correctly.
To adjust the carburetor of the Makita chainsaw, like most other models, there are three adjusting screws. Although some manufacturers carefully removed two of them, leaving only one for the user's experiments. So, three screws, on the carburetor body, they are indicated by the following letters:
- L - this screw is used to adjust low engine speed;
- H - high speed adjustment;
- T - to adjust the idle speed (it is left for experiments).
In general, the carburetors have already been adjusted by the manufacturer for optimal operation, and the screws are designed to more accurately adjust the carburetor of the Champion chainsaw and others, in difficult climatic conditions such as highlands, etc. Since the air is thinner there, more precise tuning is required for the instrument to operate. This is not necessary under normal conditions.
To adjust the carburetor of the Goodluck chainsaw, as well as other brands, two screws L and H are used to create the appropriate quality of the fuel mixture. To create a lean mixture, the screws are turned clockwise, this allows you to increase the number of revolutions, i.e. thus, set high revs. Accordingly, when turning the screws counterclockwise, the mixture turns out to be more saturated, this regulates the low number of engine revolutions. Thus, when adjusting the carburetor of the Partner chainsaw, by turning the screws clockwise, we increase the number of revolutions, counterclockwise, we decrease it.
With any adjustment of the carburetor of a Chinese chainsaw or other, a number of requirements must be observed:
- fine adjustment is always carried out with a warm engine (engine operation for at least 10 minutes);
- the condition of the air filter must be satisfactory, i.e. clean and not clogged;
- when turning the chain with the adjusting screw T, it is necessary to achieve its complete stop, for this the screw is turned counterclockwise.
And do not forget about our own safety, the chain should be directed in the opposite direction to us, the saw should stand securely on a flat surface and not touch any objects with the cutting part. With fine adjustment, the screws are adjusted in the following sequence L - H - T. With the screw L it is necessary to "find" the maximum number of engine revolutions. To do this, turn the screw clockwise, or in the opposite direction, until we "find" the maximum. This is where a tachometer is needed, or a sensitive ear for music, and you should know the sound of the maximum engine speed, if you overdo it, especially with the H regulator, the engine will fail. Repair will cost a pretty penny, therefore we strongly recommend entrusting such work to a professional.
If you have a tachometer in stock and know the maximum number of revolutions of your engine, then you can, at your own peril and risk, try to bring the adjustment to the end. It will look something like this: we find the closest value of the revolutions with the L regulator, then with the same regulators we return them counterclockwise by a quarter of the screw turn. We leave and go to the regulator H, and if you tighten it too much, the engine will fail.
We turn this regulator ¼ turn of the screw counterclockwise (we warm up the engine before this). We listen carefully or orient ourselves to the tachometer. If to sound - our ideal, when the engine at maximum works like a four-stroke engine. If the mixture is too rich, the sound is squealing. You can try to achieve an average value, not have an ideal, but remove the squealing sound with a screw. And if the work of the saw suits you, it is better to leave it as it is, it is better than to be left without an engine.
If you managed to more or less adjust the screws L and H, then there is little left - adjust the idle speed. The ideal here is to ensure that the engine runs evenly in all positions, until the chain starts moving. Turn this screw counterclockwise until the chain stops. If this cannot be achieved, the help of a specialist is needed. An unadjusted chainsaw is a very dangerous thing.
A well-adjusted carburetor is:
- the chain is idling;
- the engine accelerates quickly;
- engine operation resembles a four-stroke engine.
Below is a video of adjusting the carburetor of a chainsaw