I have a Homelite Classic 200 chainsaw. When I recieved the saw 8 years ago from my father I couldn't get it to run. I didn't have a need for it, so it sat on the shelf (with no gas in it). I now have a use for it, so I took apart the carb, cleaned it and reassembled everything. It finally runs, but at high RPM it stalls. Sometimes it will run for 20 seconds with no problem, but other times it will die as soon as I squeeze the throttle. I've played with the adjustment screws for high and low running, but no luck. It seems to idle just fine. Any thoughts??