Chainsaw is one of the irreplaceabletools in a private household. It is very important that this tool functions continuously and without interruption. The quality of the chainsaw's operation largely depends on the reliability of the carburetor. As it is used Walbro. This carburetor is quite reliable. But he sometimes needs adjustment, prevention and repair. Well, let's look at the features of this node.
The device is supplied in an aluminum casing,which is made by casting. Inside it there are internal channels with contours. These are diffusers. Air passes through them, which is then sucked up by the internal combustion engine.
Carburetor Walbro for chainsaw functions forthe pressure change in the crankcase of the motor. At the beginning of the intake stroke, the air begins to flow through the diffuser by means of a vacuum. Its volume depends on the speed of the motor and its load.
How to understand that the carburettor adjustment is required?
There are several features that canTalk about the incorrect operation of the Walbro device. Carburetor in these cases must be adjusted. If the engine chainsaw starts with great difficulty and immediately after the start of stall, the cause of this phenomenon in a non-optimal fuel mixture. In other words, she is too poor. Also, the carburetor requires tuning, if suddenly the saw began consuming too much fuel. Another of the signs is the more amount of exhaust gas. This is a signal that the mixture burns incompletely. She's too rich. The fixing screws may be broken. This happens due to strong vibrations and various defects of the protective cap. This phenomenon is very rare in Walbro products. The carburetor can then be easily repaired. Another problem is clogging. Often, the carburetor channels, diffuser and cavities may become dirty due to poor quality fuel or a defective air filter. Too worn out engine pistons also affect the operation of the carburetor.
Identification of problems in the carburetor and typical faults
Often owners of chainsaws face a leakfuel. To diagnose this, an external inspection is necessary. To do this, the device is recommended to remove and check the integrity of the gasket. It can be found between the device and the engine casing. If the gasket is in order, then check the device for leaks. All faults, which we will consider below, affect the level of tightness. Many of them can be corrected if you purchase a repair kit for the Walbro carburetor and replace the damaged or broken parts.
How to check the tightness?
The fuel supply hose is put on the inlet channelmeasuring device. Then the faucet opens, if there is one. Further, a certain amount of air is pumped into the cavity of the carburetor. In this case, the manometer should show at least 0.4 bar. If after a while the pressure remains the same, then you have a working carburettor Walbro. Repair is necessary if the pressure drops. There may be several reasons.
Sometimes the needle in the valve can not fullyclose it. This situation can occur due to blockages, heavy wear or a damaged needle cone. The lever of the valve also loses its mobility, its geometry is disturbed. The elasticity of the spring changes.
The tightness is reduced due to the loss of the shape of the control membrane. This can occur due to overheating, prolonged operation of the device.
Inlet and outlet valve
This problem can occur in the fuel pump.
Adjusting the carburetor
The setup process is pretty simple, especially ifalready have a similar experience. The first thing you need to do is to tighten the screws, which are responsible for the maximum and minimum revolutions, in a clockwise direction. They can be designated as H and L. They should be screwed to the stop. Then, for half the turn, the screws are unscrewed. All manipulations are carried out on a muffled motor. After completing this procedure, the motor must be started and warmed up at medium revs.
This screw is recommended to be screwed in a counter-clockwise direction until the engine runs as smoothly as possible.
Testing work after setup
It is necessary to check how the carburettor worksWalbro. Adjustment may not produce the desired result. For testing, the engine is started, heated and gently pressed on the accelerator. If, as a result, the turnover has risen to the maximum, then everything works correctly. If this does not happen, screw L is turned anti-clockwise by 1/8 turn. The maximum engine speed of the chainsaw is about 11.5 thousand revolutions per minute. If their number is higher, this can cause disturbances in the ignition system. In the event of a malfunction, screw H is turned counter-clockwise, thereby reducing the maximum speed.
Knowing the Walbro carburetor device and its principleaction, you can easily adjust it to work in the required modes. The device is simple and can cope with it even people without experience. Any problems can be eliminated with their own hands without significant costs.