Sp...I got this used 150cc with 3k miles on it and its running fine. Then I take it on a full throttle, 10 mile ride and park it at my destination. When I come back to it 2 hours later its really jerky when taking off from a stop. Once it gets fully heated up its ok...doesnt do it any more. Then you park it and it starts doing it again. Its like the clutch is throwing out really hard. Valves just adjusted and new plug.