Pick up a replacement carb online for $15-$20 (I replaced the carbs on my chainsaws for $15 and they worked great-cost same as a rebuld kit) and it will probably run better than it has for the last few years.
Run a good quality engine/fuel system cleaner through it for a few tank of fresh fuel. Probably the ethynol has finally done it's dreaded deed to the fuel system. I spray the engine and surrounding components with diluted peppermint spray (They hate it) and soak a few cotton balls with the...