I have a chain saw that wants to stall when run wide open. The saw runs fine off choke up to 1/2 throttle, and on half choke up to 3/4 throttle. I have tried primming it as it reaches high rmp and that doesn't help. It sounds like it just isn't getting enough gas. I had a handheld blower that did this and it was the carb that needed to be re-built. Does anyone else have any ideas of what it could be?