Chainsaw Carburetor. This is the element that is responsible for mixing the air-fuel mixture. Not only the stability of the engine, but also the speed of the entire chainsaw depends on the condition and serviceability of this important unit. In this regard, each owner of a garden tool should study the design of the carburetor, as well as familiarize themselves with the rules for its maintenance and repair.
Chainsaw carburetor device
Most modern chainsaws are equipped with almost the same carburetors. They practically do not differ from each other, and work on a similar principle. The only difference between cameras from different manufacturers is the material from which they are made. In expensive American, Swedish and German chainsaws, cameras are made from reliable alloys that are coated with protective coatings. Cheap Chinese and Korean chainsaws are equipped with units made of cheap materials.
Each carburetor consists of the following elements:
- aluminum case with one piece construction. Inside the case there is an inlet fitting, a main screw, a pulse channel, a bolt for adjusting the engine when idling;
- throttle. it is responsible for adjusting the amount of air required to enrich the fuel mixture;
- diffuser. located next to the inlet of the camera;
- atomizer. designed to supply the fuel mixture directly to the carburetor chamber;
- float chamber. there is a float in it, which is triggered in case of insufficient fuel;
- jets. are valves that are responsible for adjusting the amount of fuel.
This carburetor circuit of a chainsaw is as simple and effective as possible. In some models of garden tools, it can be supplemented with additional nozzles, oil seals or filters.
The principle of operation of the carburetor chainsaw is quite simple. At the time of starting the engine, an air damper located at the bottom of the housing opens. In this case, a vacuum is formed in the float and air chambers caused by the movement of the piston. As a result, the standard diffuser is triggered, which begins to suck in air. The amount of intake air depends on the degree of opening of the damper. When the piston is triggered through the inlet fitting, fuel begins to flow into the chamber. Its quantity and flow rate depend on the position of the jets.
Subsequently, the fuel in the air chamber begins to mix with air. After that, the finished air-fuel mixture passes through the intake valves, from where it is sent to the combustion chamber of the saw engine.
Chainsaw carburetor adjustment. what do beginners need to know?
Initially, all the adjusting bolts are in the factory position. this ensures the suction of the optimal amount of fuel and air. However, due to the long operation of the saw in difficult conditions, the factory settings of its carburetor may be violated. Even a slight shift of one of the bolts by 1/5 of a turn will lead to a serious disruption in the operation of the saw engine. In this regard, the operator must constantly ensure that the adjusting bolts are in optimal positions installed at the factory.
If for some reason the operation of the node was disrupted, then it will need to be reconfigured. For this, 3 adjusting bolts are provided in the unit assembly. The first of them is marked with the letter H. it is needed to configure the chainsaw engine when operating at maximum speed. A second screw marked L is used to adjust the motor while it is running at low speed. The third screw may be labeled T, S, or LA. Its task is to configure the engine when operating in idle mode.
Setting the carburetor of the chainsaw must be carried out with the engine fully operational. Immediately before adjustment, you will need to inspect the air filter and, if necessary, clean it or replace it.
Video: How to Rinse a Carburetor On a Chainsaw
How to adjust the carburetor on a chainsaw?
To set up the assembly, install the tool on a firm, level surface. It is best to adjust the chainsaw carburetor in a place protected from dust and moisture.
The node configuration process should look like this:
- First, unscrew the mounting bolts and remove the saw blade guard. This will make it possible to inspect the carburetor and, if necessary, clean it;
- Next, you need to remove the standard air filter tool. If the saw is equipped with an additional foam insert, then it also needs to be removed;
- After that, you will need a screwdriver to tighten the bolts marked H and L clockwise until it stops. This must be done very carefully so as not to break the bolts;
- Then both screws should be loosened 1.5 turns in the opposite direction;
- Next, you need to start the chainsaw motor and let it run for about 7 minutes;
- As soon as the engine cylinder heats up, you will need to start turning the bolt L until the ICE starts working at maximum speed. Immediately after this, the bolt must be turned 1/4 turn in the opposite direction;
- Then you need to configure the motor at high speeds. To do this, you need to connect an electronic tachometer to the engine, and begin to turn the bolt H until the indicators on the instrument display coincide with the instructions for the recommended maximum revolutions in the saw instructions;
- In the end, it remains to configure the operation of the internal combustion engine saws at idle. To do this, slowly turn the T bolt counterclockwise until the motor runs stably and without failures. If the motor starts to stall, turn the bolt T in the direction of the clock.
To adjust the carburetor on a chainsaw, you should work with the adjustment bolts as accurately as possible. Excessive tightening of the screws will increase the load on the engine and other important components of the garden tool.
How to wash a carburetor chainsaw?
To clean the site from strong contaminants, it is best to use a product that is sold in pressure cylinders. Complete with a cleaner there is a dispenser and a long thin tube, which makes it possible to spray the product in any hard-to-reach places.
It must be remembered that cleaning a carburetor on a chainsaw is carried out using flammable chemicals. You need to work with them in a special protective mask and only in well-ventilated areas.
To clean the carburetor on a chainsaw, the assembly will need to be partially disassembled. The throttle valve, adjusting screws, housing and other carburetor parts will need to be flushed with a balloon and set aside until it dries completely. Once all the elements have dried, the assembly can be assembled and installed back onto the chainsaw.
Gasoline does not enter the chainsaw carburetor
If the fuel does not enter the standard camera, then this can speak of several breakdowns at once. First of all, you need to check the air and fuel filter. During long-term operation of the saw, these elements absorb a large amount of dust, which further prevents the leakage of clean air and fuel. A lightly soiled filter can be cleaned with gasoline, but if the part is clogged with a large amount of dust, it will need to be replaced.
Another cause of malfunction is the needle. Sticking is characteristic of this part, especially in Chinese-made chainsaws. To fix the malfunction, in most cases it will be enough just to move the needle.
If fuel does not enter the chamber, then the saw owner should inspect the tool seals. After several months of using the tool, these parts lose their tightness. Over time, they begin to let gas in, causing the tool to stop turning on. Repair is done by replacing the seals.
When starting the saw, an important role is played by the breather. It is located near the lid of the gas tank of the saw, and performs 2 tasks at once. it maintains optimal air pressure and prevents fuel from leaking out. To check the breather, you will need to turn off the fuel pipe and see how much gasoline flows out. If it does not flow out at all, then the regular breather is clogged with garbage and dirt. In this case, you will need to clean the element and install it in place.
If fuel does not enter the chamber, then the fuel line must be checked. Most often, a Chinese hose is used to complete the budget-grade tool, which eventually loses its tightness. In this case, it will be necessary to replace the line, paying particular attention to the tightness of the channel joints.
Why is a chainsaw shooting at a carburetor?
If during the launch and operation of the instrument its owner hears sounds reminiscent of shots, then this indicates a malfunction of the unit in which the fuel is mixed. The reason for this, most likely, are such malfunctions of the carburetor of the chainsaw:
- tightened ignition. in this case, the fuel does not burn out, which leads to specific sharp shots;
- supplying a mixture of a low concentration of gasoline to the carburetor. to fix the problem, you will need to configure the nozzles.
If the firing sound comes from the side of the muffler, then the problem is oversaturation of the fuel mixture with gasoline. If there is too little air in the fuel, it will burn not only in the chamber, but also in the muffler. This will be evidenced by a large amount of soot on the inner walls of the muffler.