Its probably the carburetor which is easily disassembled and clean using a Carb cleaner. You will be surprised just how easy it is.
I have the same engine, it was stored for a couple years and had problems running smooth. I took apart the Carb and cleaned it and of will start on the first pull and runs smooth as ever.
The fuel is the problem, not the engine
Last edited by T37Chef; 07-08-2013 at 07:56 AM.