You will need
- Screwdriver, tachometer, a technical passport of a chainsaw
Setting the carburetor of a chainsaw is to adjust the position of the nozzles. Typically, the carburetor has three screws for adjustment screw low speed jet screw needle valve high speed adjustment screw idle speed of the saw.
The first two screw regulates the ratio of fuel mixture and air, which is determined by the opening of the valve throttle. If you need to impoverish the mixture, turn the screw clockwise if mixture is necessary to enrich and to increase the number of revolutions the screw must be unscrewed by turning counterclockwise.
To adjust the idle speed use suitable screw. Turning it clockwise, you will increase the number of revolutions, while rotating the screw counter-clockwise the number of revolutions decreases.
After buying the saw for several hours of work you must save the settings made at the factory (there is a carb adjust for a richer mixture). You can then tune the carb yourself.
When adjusting, keep in mind that the screw rotation nozzle high rpm affect the power and frequency of rotation of the chain. The depletion of the combustible mixture leads to excess turnover and can lead the saw out of action.
After warming up the engine saw at full speed for a few seconds, turn the screw high speed jet counterclockwise and allow the device to work for 10 seconds. Using a tachometer, check the maximum speed. They should correspond to the number of turns stated in the passport to the chainsaw. If too lean the saw starts "screaming", and when adjusting at the excessively rich mixture can smoke muffler.
Optimal adjustment of the parameters of a chainsaw should be done by an expert with access to the tachometer.