If the saw is warmed up AND the choke is off, and the saw kills when the throttle is opened, it sounds like you need to open up the low speed jet on the carburetor a little bit. The low jet is the one that is closer to the crankcase on the side of the carb. Open the jet just a little bit and try to pop the throttle. Do this, a little at a time, until it goes from idle to full tilt without a burp or stall. When I adjust the carb, I make adjustmentsin increments equal to the width of the slot in the adjusting screw.
If this does not work, bring the saw to a repair shop.
Tom