Sorry for the thread necro but I've got a Kymco ZX50 "super fever" (HAHA) in here with the same issue. It fires right up and idles fine. I took it out and rode it around the lot for about 5 mins and it was like I hit the kill switch - it just died. It was the end of the day so I pushed it back into the shop and left it. I came in this morning and it fired right up. I went through the carb and that's perfectly clean. Does anyone have any wiring diagrams or testing info for the stator for these units? We're a Vespa/Piaggio dealer and former Arctic Cat dealer so I know electrical testing, I just need to know what kind of values I should be seeing. I'm guessing it's either the stator or coil that's breaking down when hot. Thanks in advance!