Disassembly Of The Carburetor Stihl 180
The chainsaw stalls on hot after work and warming up
- Problems with the carburetor (how to fix and diagnose below);
- Overheating cooling problems. Clean your saw;
- Lack of air supply;
Removing the carburetor
The removal process is best shown in the attached below. It also demonstrates the basic minimum steps in order to bring the node into working order. Schematically, this process looks like this: remove the cover, rods, unscrew the unit.
Nozzle
The fuel injector is mounted in the carburetor body in such a way that it is a connecting link between the distribution chamber and the cavity in which the throttle valve is installed. Simultaneously with the fuel, air is supplied to the nozzle and an air mixture is formed. The injector has a check valve that blocks the flow of air in the reverse sequence, that is, from the throttle chamber to the distribution chamber.
The chainsaw starts to stall or change rpm when tilted to the side. In vertical, everything is fine, when turning, the revolutions fall (or grow) and it stalls
It is associated with the design features of its fuel system, filling the chambers. In addition, it is imperative to check the gas pump, sometimes the problem may be in it.
Who can repair carburetors
All of the above applies to any models of chainsaws, including petrol trimmers, scythes and other equipment. Adjusted, of course, for design features.
There is an opinion that it is better not to climb inside the chainsaw on your own. For those who are used to working with a hammer and sledgehammer, perhaps this is so. Otherwise, any neat person who does not shake hands can fix any problem with his work. In general, this is a job available to anyone.
Distribution chamber
In the distribution chamber, as in the fuel pump, there is also a membrane that opens and regulates the fuel supply by pressing a special rocker, while raising its needle valve.
The chamber cover is the compensator body, which is attached to the carburetor with four screws; a gasket is installed between the body and the cover, which increases the height of the chamber and is responsible for sealing.
Who can repair carburetors
All of the above applies to any models of chainsaws, including petrol trimmers, scythes and other equipment. Adjusted, of course, for design features.
There is an opinion that it is better not to climb inside the chainsaw on your own. For those who are used to working with a hammer and sledgehammer, perhaps this is so. Otherwise, any neat person who does not shake hands can fix any problem with his work. In general, this is a job available to anyone.
The chainsaw does not idle. Either she stalls at idle, or they walk, or high.
The idle jet may be clogged. Cleaning is required. How to do it below. But for now, about alternative reasons.
It is possible that the problem is in the fuel system. Check fuel hoses, fuel supply.
Sometimes problems with rpm (or rather lack of them) are solved by cleaning the fuel tank check valve (gasoline tries to leave the tank, but air does not return instead). It looks like the one shown in the figure below:
Remember to tweak the carburetor in the only possible way to change the amount of air supplied, which affects idle speed a lot. Everything is described in the instructions for the saw. For those who are too lazy to go into the instructions, here is a screenshot:
Fuel pump
Specifically, a fuel pump is installed in the carburetor body, which operates under the action of an air pulse from the crankcase of the chainsaw, which is transmitted through special channels. A diaphragm is installed in the pump; specifically, it is responsible for pumping fuel under the action of an impulse. A gasket is installed between the diaphragm and the body, which is responsible for the density of the fuel pump.
Nozzle
The nozzle for supplying fuel is built into the carburetor body in such a way that it is a connecting link between the distribution chamber and the cavity in which the throttle valve is installed. Directly with fuel, air is supplied to the nozzle and an air mixture appears. The nozzle has a revolving valve that blocks the flow of air in the recirculation sequence, in other words, from the throttle chamber to the dispersion chamber.