Among the owners of the private sector, the chainsaw is an indispensable tool for which there is always a use. This is a mechanism that consists of parts carefully fitted to each other. The main element of the whole structure is the carburetor. As in older cars, its role is to prepare a mixture of fuel and air for its further supply to the engine. And since the element works constantly when using the tool, it is necessary to service it periodically. How to adjust a chainsaw carburetor? Every owner of this mechanism wants to know the answer to this question. Actually, this is what we will do now.
Signs of Carburetor Adjustment Needed
How do you know when it's time for tuning? As a rule, this procedure is done in a mandatoryorder when loose adjustment screws are detected.
However, there are other signs that indicate that it is time for a carburetor adjustment. In particular, you should pay attention to the following symptoms:
- Sensation of strong vibration - this damages the protective cap, which, in turn, leads to the loss of fixation of all three adjusting screws.
- Wear of the piston part of the engine - adjusting the carburetor in this case will extend the life of the tool, but only for a certain period of time. In any case, the piston group must be replaced as soon as possible.
- Clogs - These are caused by poor quality gasoline, scale, clogged or damaged filters.
- Increased "appetite" is a clear reason to think about how to adjust the carburetor on a Stihl chainsaw or any other model. The phenomenon is accompanied by an increase in the amount of exhaust gases, which does not lead to anything good.
- The engine stalls immediately after the factory or does not start at all - this happens as a result of a lack of fuel against the background of excess air.
All these signs clearly indicate the need for carburetor adjustment. And the sooner the procedure is carried out, the better for the instrument. Otherwise, other equally important components of the engine and the chainsaw in particular may fail.
How does a carburetor work?
First of all, it is worth understanding how such an integral element workschainsaws.
And in order to understand how to adjust the carburetor on a Husqvarna chainsaw, consider its device using this tool as an example. The whole structure is represented by the following elements:
- Fuel pump. Thanks to this device, the working mixture enters the carburetor.
- Aperture. Due to this element, the supply of a combustible mixture to the engine is limited.
- Float chamber. Fuel is collected here, while its level is controlled by a float. As needed, the fuel is sent to the main chamber, where it mixes with air.
- Working chamber. Air passes through it and fuel is injected. Moreover, the amount of the supplied mixture is regulated by the throttle valve, which is located here.
- Diffuser. This is a narrowed section of the tube that provides air to the place where the fuel is injected.
- Needle valve. Thanks to him, the fuel supply is regulated.
- Jet. These are the screws that regulate the fuel supply at low and high speeds, including the idle element.
All of this is encased in a housing that has clamp bolts with a set of gaskets. The carburetor device has one more damper in addition to the throttle - it is located at the inlet of the air filter. It lowers the air supply, making the mixture saturated for easy cold starting.
The question is howadjusting the carburetor on a Husqvarna 142 chainsaw (or another manufacturer) worries many people living in private households. However, before that, it is still worth getting acquainted with the principle of operation of the carburetor. And more on that later.
Operation principle
The principle of the carburetor is easy to understand. Air is sucked in through the tube at a speed controlled by a damper. This activates the float of the first chamber. Passing through the diffuser, the air mixes with the fuel and is immediately sprayed. Next, the finished mixture enters the engine cylinder, passing through the inlet channel. And the more fuel will flow, the higher the engine speed.
Regardless of the manufacturer and model of tools, all carburetors have an identical structure and work on the same principle. The difference lies only in the material of the constituent elements and their location in the carburetor body.
Adjustment tools
How to adjust the carburetor on the Partner chainsaw? First of all, it is necessary to understand the purpose of the three screws that are equipped with models 142, 240, 236, 137 and other similar ones. Each of them has its own designation and purpose:
- Screw L - low speed is adjusted with it.
- Screw H - it adjusts the motor to operate at high speeds.
- Screw T - adjusts idle speed.
Some models of chainsaws are equipped with only one screw marked T. Accordingly, the adjustment of carburetors in this case is done by manipulatingwith just him alone.
In addition, it should be understood that regardless of the number of screws, the optimal operation of the chainsaw is provided by the carburetor settings that were set at the factory. As for the screws themselves, their presence is due to the operation of the tool under certain weather conditions.
Preparation
How to adjust the carburetor on the Stihl 180 chainsaw? This procedure requires thorough preparation. And first you need to refer to the chainsaw instruction manual and find information in it regarding the angle of rotation of the screws. If you do everything in a random order, then you can simply disable the engine.
The motor itself, in turn, must be in good condition. In addition, you need to inspect the air filter and clean it if necessary. Otherwise, it will not pass the required amount of air and the carburetor setting will be incorrect.
The procedure itself must be performed on a flat surface. In this case, the tool itself should be positioned so that its chain is not directed towards the operator to avoid injury.
Adjustment procedure
The carburetor of the tool with three screws is adjusted by manipulating two of them - L and H. To increase the speed, turn them in the direction of rotation clockwise, to decrease - in the opposite direction. It is worth using a special screwdriver to prevent it from slipping off the screws and damaging the threads on their "hats".
The decision on how to adjust the carburetor on the Partner 350 chainsaw involves two stages - initial and main. The actual algorithm of actions may look like this:
- The first step is to turn both screws fully clockwise.
- Then screw L and screw H turn one and a half turns in the opposite direction.
- Second stage - the chainsaw is started and left for a while to fully warm up. 12-15 minutes will be enough.
- Now you should turn another - the third screw T until the moment when the engine starts to work stably, and the chain on the bar does not rotate.
In the course of these manipulations, one should not rush. The slower the propellers turn, the more noticeable changes in engine operation can be felt.
Check
We have already familiarized ourselves with how to properly adjust the carburetor on a chainsaw. However, after the procedure, it is imperative to check the "acceleration" of the power unit, set the maximum number of revolutions and its operation in idle mode.
The engine will pass the test if, during a smooth press on the accelerator, the speed increases from low (2800) to maximum (15000) in a short period of time. If this does not happen, then the screw L should be turned counterclockwise. In this case, its revolution should not exceed 1/8 of a full circle.
Measuring the maximum speed is screw H, in addition, you need a tachometer. The maximum number of revolutions should not exceed 15000. This is exactly what the mentioned measuring device is for. If there are a lot of them, you need to lower them by turning the screw counterclockwise. If it is necessary to increase them, the adjusting element should be turned in the opposite direction.
Knowing how to adjust the chainsaw carburetor is important because the further operation of the tool, including the duration of its service life, will depend on this. It is also not worth neglecting the check in order to avoid many problems.
Failures
If, after the chainsaw has been started and when you press the trigger, dips are felt well during the set of revolutions, it is worth manipulating the screw L. To do this, it must be turned no more than a quarter of a full turn in both directions. At the same time, evaluate the reaction of the motor to pressing the gas.
You need to try to find the position of the adjusting screw at which the engine will accelerate quickly and evenly. It is also worth not rushing here, and turning the screw through a larger angle does not make sense, because it is simply not able to unwind on its own. In this regard, a quarter of a turn will be enough.
A number of nuances
After adjusting the carburetor, the chainsaw engine should easily gain and lose speed. Moreover, his work should be stable, regardless of their number. But if, after manipulating the screws, the chain rotates in idle mode,therefore, the adjustment was not carried out correctly. Then you need to adjust the position of the screw T.
How to adjust the chainsaw carburetor, and do it right? To do this, one important point must be mentioned. When setting up the carburetor of the Husqvarna chainsaw, it is worth considering the response time to the rotation of the screws. The settings do not change instantly, but after 5-10 seconds. It is for this reason that manipulations should be carried out slowly.
Another sign that indicates incorrect carburetor adjustment is smoking during tool operation, and very strong. This is evidence that too much fuel is entering the combustion chamber. In this case, adjustment of screw L is necessary.
Chainsaws brand "Shtil" and "Partner"
In the models "Shtil" 180, 250, 361, and "Partner" 351, 350, the carburetor settings are carried out with the same screws as in the Husqvarna chainsaw - H and L. This is how the proportions of gasoline and air are set. Screw T is also responsible for setting the idle speed. Although some models may have a different marking of this mode - S. In other words, the adjustment procedure itself, if necessary, is carried out according to a single scheme for almost any model.
Breaking in the chainsaw
Buying a chainsaw is no less important than adjusting its carburetor. If it is purchased from the hands (which is considered an acquisition in the secondary market), then there are no special problemsarises. However, a run-in is necessary for a new tool. This term is the process of grinding in engine parts and CPG. And while the chainsaw is being run-in, the necessary and correct gaps are finally formed in the tool engine. This process is just as important as solving the problem of how to adjust the carburetor of a chainsaw.
For this purpose, the appropriate settings are set at the factory - the revolutions are 600-700 less than required in the usual mode of operation. Thus, the process of running in the power unit is carried out in a gentle mode. For this reason, you should not immediately after acquiring a tool to configure it. In any case, this must be done, but not before the break-in is over.
