had a prob with my stihl 024av. wouldnt start. took it to my local guy....said that my saw had low compression(85lb) this is a saw that has not seen much use and is taken very good care of). so, he suggested junking it(which he would do for me) and buying one of his new husky's. so, rather than that, took it home. checked the compression myself....got 120lbs(marginal). pulled the thing apart(never did such a thing). anyway, only thing that i found was that a SMALL SCREEN IN THE CARB WAS CLOGGED. dont really know what that screen is responsible for. put it all back together, baselined the hi/lo carb settings. NOW, STARTS FINE AND RUNS GREAT.....so, thanks for the help that this forum gave me.....