Not so long ago, a chainsaw was considered a real luxury, as it was expensive and used only by professionals. Today, this tool can be purchased by everyone. Consumer models have appeared on the market, which are light in weight and have a limited set of functions.
Modern chainsaw is powered by a single-cylinder two-stroke carbureted engine. Previously, models of such equipment were equipped with contact ignition. Today, almost all manufacturers are introducing electronic ignition. Thanks to this, there is no need to adjust the gap between the contacts and constantly clean them.
What is a carburetor for
For the engine to work, the air-fuel mixture is combined in the carburetor. A special flap allows it to be manually enriched for specific tasks, such as working with hardwood. The performance of the engine and the performance of the tool itself depend on the technical condition of the carburetor and its serviceability.
Device
Before starting operation, it is necessary to consider the device and principle of operation of the chainsaw carburetor. Almost all models use parts that have an identical design. The exception is Chinese equipment carburetors. They may not contain some spare parts, and a number of components are made of cheap materials. Among the main components of the carburetor should be highlighted:
- Case.
- Diffuser.
- Atomizer.
- Jets.
- Float chamber.
As for the case, it is made of aluminum to facilitate the construction. It also has a one-piece mold. Inside there is a diffuser, an impulse channel, an inlet fitting, an idle screw, a main screw, and a damper. The latter is needed to adjust the air supply.
There are other elements in the body. Considering the device and the principle of operation of the carburetor for the Partner chainsaw, you can notice that the described element of the device also has a diffuser, which is located at the inlet. Special valves are jets. They serve to regulate the amount of fuel.
Operating principle
Before you start adjusting the carburetor, you need to understand the principle of its operation. When the engine starts, the air damper in the lower part of the housing opens. In the float chamber and air channela vacuum occurs. It is caused by the stroke of the piston. This helps the airflow to be sucked in through the diffuser.
The principle of operation of the Husqvarna chainsaw carburetor is exactly the same. With this tool, the air suction intensity is adjusted by the position of the air damper. Through the inlet fitting from the tank, gasoline enters the float chamber. With the help of jets, the speed of the passage of fuel into the diffuser is adjusted. There it mixes with air. The prepared composition is in the inlet channels. From there it is directed to the combustion chamber of the cylinder.
What else you need to know
The principle of operation of the carburetor of the Stihl chainsaw is the same as that of the model described above. Additionally, it can be noted that the needle is responsible for spraying fuel into the float chamber. The more fuel, after mixing with air, enters the engine, the higher the engine speed will be.
Regardless of the chainsaw model and manufacturer, modern tools are usually equipped with carburetors that have an identical design. They work, respectively, on the same principle. The main difference is only in the location of the nodes in the carburetor device and spare parts materials.
Features of the chainsaw, indicating the need to adjust the carburetor
The principle of operation of the carburetor chainsaw "Partner" is now known to you. This helps to understand how to make adjustments. She isis necessary when some difficulties appear in the operation of the tool. The standard new chainsaw has factory settings according to which fuel is supplied. However, for proper break-in, limit the maximum engine speed.
The adjusting screws will help in this matter. They are located on the carburetor body. Precise adjustment of the supply of the combustible mixture is carried out after running. The carburetor is also subject to adjustment with strong vibration. This is indicated by some operational problems. If the internal combustion engine immediately stalls or starts poorly, then this unit requires debugging.
Sometimes it also happens that the engine, although it starts, develops speed reluctantly or stalls. Having studied the principle of operation of the Stihl 180 chainsaw carburetor, you will begin to understand that the piston group may wear out during operation. In this case, adjusting the carburetor may help, but will only be a temporary measure.
What else could be wrong
When using the device, it will be noticeable that the engine does not idle or there is an increased consumption of gasoline. Because of this, the unit produces a lot of smoke, the muffler is dirty, and the candles are covered with soot. All this contributes to a decrease in engine power. Your action should be to tune the carburetor.
Preparing for adjustment
When you know how the chainsaw carburetor works, you can adjust it. For correct settingyou will need a technical passport, where you can get acquainted with the angles of rotation of the adjusting screws. You will definitely need a screwdriver. You can take a special one designed for adjustment, or a regular one.
The tool is placed on a flat surface. It could be a table. The equipment must be positioned so that the saw bar points in the opposite direction. The motor must first be turned off. Using a screwdriver or wrench, you need to unscrew the mount that holds the housing cover. It must be removed to allow access to the carburetor.
Now you can remove the air filter that covers the assembly you need. Sometimes a shock-absorbing foam rubber insert is installed on top. It should also be removed. Now you can do the setup itself. The screws must be turned carefully so as not to break them. Screws L and H are usually adjusted first, which are unscrewed one and a half turns.
Setting features
To perform this procedure correctly is possible only under certain conditions. For example, the cleaning filter should not be dirty (this applies to air and gasoline). Valves and jets must be clean and diaphragms must be free from damage. You also need to make sure that the needle valve is working. It is also important that the required amount of fuel enters the float chamber.
Expert Tips
Working principlethe carburetor of the Chinese chainsaw has been described above. During the operation of the equipment, you will be able to understand when it requires debugging. Before starting these works, warm up the engine at minimum or idle speed for 15 minutes. Using the L knob, you should be able to idle at about 2000 rpm. It is important to pay attention to how the engine picks them up. Acceleration should be quite fast when the accelerator lever is actuated.
If you notice a RPM dip, the screw needs to be turned out a little to eliminate this phenomenon, as it is caused by insufficient fuel enrichment. The principle of operation of the Partner 350 chainsaw carburetor will allow you to understand how to configure this unit. For example, when the mixture supply at low speeds is adjusted, it is necessary to tighten the screw T. This must be done until you notice the rotation of the chain. The screw is then unscrewed by half or a third.
It is important to follow the summing up of the clutch mechanism. At idle, the saw should not rotate. This is the norm. The H screw can be used to compensate for over- or under-revs that may be caused by fuel changes, ambient humidity, or changes in oil concentration.
High setting can be lost when low rpm is not adjusted correctly. The principles of operation of the chainsaw carburetor will allow you to understand that it is better not to touch the H screw at all if you do not have enough experience. When the adjustment is carried out by an incompetent person, there is a risk that theat high speeds, a lean mixture will enter the combustion chamber. Such operation of the engine under load can cause rapid wear of the piston system. All this will lead to a failure in the ignition system.
High RPM Adjustment
You can set up a carburetor in a simple way. This is done by unscrewing or tightening the screw H. This must be done until the engine develops approximately 15,000 rpm at maximum speed. Measurements should be made with a tachometer.
Knowing the principle of operation of the chainsaw carburetor, you will be aware that under load, the frequency of the spark charge can decrease by about 15%. The frequency should be measured with an oscilloscope. This value can vary from 230 to 250 Hz. To comply with safety measures, it is necessary to tune the internal combustion engine at a slightly lower speed.
If you have a Chinese chainsaw in front of you, its carburetor is adjusted according to the same principle. There are holes on the case into which you need to insert a flat screwdriver to adjust the speed. Once you are familiar with the principle of operation of this type of chainsaw carburetor, you will know that each hole has its own designation. For example, near the top you can see the letter T, while near the bottom you can see the letters L and H.
Conclusion
The chainsaw has become an indispensable tool in private households. Its smooth functioning is an important factor for efficient operation. Quality performance of tasks depends on how effectively performs its functionscarburetor. To understand this issue, you need to familiarize yourself with the principle of operation of this node, as well as know how to properly adjust it.
But initially the chainsaw comes with factory settings. If you do not have enough experience in the issue of adjustment, it is better to contact a service center. As for the period when the chainsaw is still under warranty. After all, if you begin to disassemble the case during this period, it may void the warranty.
