by Rick Forrester
Keeping the trail free of fallen trees or overhanging branches routinely requires the use of chainsaws and powered extendable pole saws. With weekly use, the saws routinely need servicing, especially carburetor cleaning and adjustment. Adjustments change based on the condition of the saw, grade of gas used, oil/gas ratio, elevation of where the saw is being used, and even the time of year when the gas is purchased. One of our tools of the trade is a carburetor service kit that contains the specially shaped wrenches, reamers, and brushes used by various saw manufacturers such as Stihl, Echo, Ryobi, Poulan, etc. It also has a tachometer to measure engine RPM (revolutions per minute).
There are typically three screws on a two-cycle engine that need adjustment: L for low speed, H for high speed, and I or LA for the idler jet. The different manufacturers have different letters for the three screws but the carbs generally perform the same way. Although many people can hear the various sounds of a properly running saw when idling, cutting, or running at high speed, the use of a tachometer gives you an extremely helpful visual display of the rpms. It is especially if you have bad hearing! For an RPM example, many Stihl saws run at a high-speed rpm of around 10-14,000 and low idle around 3000 each depending on the model. The various manufacturers often don’t put the target RPM values in Owner’s Manual in order to force you to use their service departments, but they can be found in the “Service” manuals which you can buy separately from either the manufacturers’ website, authorized dealer service centers, or from independent service manual providers. However, a little internet searching can dig up the proper values for your saw. The kit the Fosters work crew uses has all the necessary tools and can be purchased from Amazon for about $30.
Keep those saws running great down on the trail!