Had issues with mine after I pulled it apart and cleaned it. Idled beautifuly, and revved up but would then die down and stall. Was doing my head in had the carby off five times and couldn’t work it out. Turned out I had mixed the choke jet and the main jet and had them the wrong way around. They are the same size to look at, but, the hole in the main jet is larger than the choke jet. Swapped them around and runs like a champion again. Hope that helps