Ok. Now it sounds like an idle circuit problem on the carburetor. Did you set the idle mixture? A general setting is to run the idle mixture screw (L) clockwise or (in) till it stops. Don't over tighten it. Then back it out counterclockwise 1-1/2 turns. Also; if the blade spins at idle or when you are pulling the starter, then replace the clutch springs. They shouldn't engage until about 3,400 rpm, and the saw should be set to idle at 2,800 rpm. A broken clutch spring keeps the clutch engaged, and thus makes the saw lug the belt and blade at idle. On the carb; find out if it's a Walbro or a Tillotson carb, then get a kit with the welch soft plug in it. Take the welch plug that is in the carb out with a point carfully. Once it's out, take a small strand of wire and clean out the tiny fuel feed holes. Also remove the needle and spray some WD 40 through the holes. Don't loose the needle o-ring. Don't use compressed air, as this can damage the mylar check valve on the brass high speed nozzle. This nozzle is the larger looking plug, and has a check valve which under idle conditions, acts as a check valve. :bang:If it is faulty or not holding under idle conditions, will cause a bad idle due to letting air into the fuel supply inside the the carb that feeds the idle circuit. They can be checked by carefully driving the check valve out into the center of the carb and letting it fall out. The take a small clean hose that will fit over the nozzle end only, and leave the feed hole open. Then create pressure and vacuum by blowing on the other end of the hose. It should allow air one way only. If it doesn't, then you need either a new check valve, or just simply replace the carb. Confused yet? Hope some of this helps. Thanks