Hi I'm James. I just fitted a Gas Bike 66cc engine kit and eventually after bleeding the carb it started and ran for about 15 minutes. Will not start again. Seems to be a lack of spark. I'm in the same boat as Freaked Out member. Dont know whether it's the plug or ignition unit. Did connect plug to car and it sparks. Wiring all seems to be ok. Did remove kill switch from system and made no difference. Any more advice. Thanks, bye for now James.