Chain Saw
Cut Dry. Cut Clean.
Chain brake
The greatest hazard when working with a chainsaw is if the saw kicks back. Kickback can happen if something contacts the upper quadrant of the tip of the bar, or if you try to cut with that same quadrant (the “kickback sector”). The bar tip will then try to climb upwards, and the saw will be thrown backwards by the force of the rotating chain.
You should always make sure the bar tip does not contact anything, and never try to cut with the kickback sector of the bar.
Engine
The carburetor may need to be adjusted, i.e. when operating in high or low altitudes, or their fuel oil-to-gasoline ratios must be adjusted to run properly. Electronically controlled carburetors make all adjustments automatically.
To ensure clean air supply to the carburetor, chainsaw producers offer different filters with fine or less fine mesh. In clean surrounding air a less fine filter can be used, in dusty environment the other.
Drive mechanism
Typically a centrifugal clutch and sprocket. The centrifugal clutch expands with increasing speed, engaging a drum. On this drum sits either a fixed sprocket or an exchangeable one. The clutch has three jobs: When the engine runs idle (typically 2500-2700 rpm) the chain does not move. When the clutch is engaged and the chain stops in the wood or another reason, it protects the engine. Most importantly, it protects the operator in case of a kickback. Here the chain brake stops the drum and the clutch releases immediately.