chainsaw clutch

I use a husqvarna 440 chainsaw and everytime I use it the clutch smokes it has a sharp chain and full tank

Hi. Just recently my 1980 056 mag II has started acting up. i just use it for cutting big firewood. Anyways, the chain won't stop spinning, even when idling. I adjusted the idle screw on the carb to get it to slow down, hopefully thinking that would remedy this problem...but the saw just dies...