I have a bikeberry 66cc/80cc motorized bicycle engine kit and I must say that I am very impressed with it it came with an upgraded cdi, three prong spark plug, only 2 wires from the motor as opposed to three opened transfer ports, and 8mm mounting studs and hex bolts for intake manifold exhaust and everywhere else that needs fastening I call myself trying to port the intake and the exhaust port but not much Ia mixture of 6oz oil to 1 gallon of gas probably not right but it was running well but my problem is that if I'm not at wot it 4 strokes and the top speed so far is 34mph can anyone help me stop the 4 stroking at 1/4 1/2 throttle I would really appreciate it signed slawdog