The carburettor on a Husqvarna 445 chain saw regulates engine speed. Air and fuel are mixed in the carburettor, and this mix can be adjusted. The carburettor is controlled using the throttle. When the chain saw's carburettor is adjusted properly, the chain saw will accelerate quickly and cleanly without any stuttering. A properly adjusted carburettor also stops the chain from rotating on idle. You can adjust the carburettor in a Husqvarna 445 chain saw quickly and easily.
Start the Husqvarna 445 chain saw. Watch the chain as it idles and make sure it's not rotating. If the chain is rotating, adjust the carburettor idle speed with the carburettor screws. The screws are located on the carburettor, which is between the fuel tank and the starter handle on the left side viewed from behind.
Turn the T-screw clockwise with the engine running until the chain starts to rotate. Then turn the T-screw counterclockwise until the chain stops.
Listen to the engine after you've made the adjustment. The engine should run smoothly in all positions. Make further adjustments to the T-screw if it doesn't.
Turn the Husqvarna 445 chain saw off, then turn it back on to test how it starts and accelerates. A too-lean mix on the L-jet screw can cause starting problems and poor acceleration. If the H-jet screw is too lean, there will be less overall power available.
Take the Husqvarna 445 chain saw in for service if you are unable to get the chain to stop at idle.