I have a 1982 Italjet 250t with a kawasaki kh125 engine installed. The engine has stopped running and after three months i can not find any problem. At the moment i think there might be a leak between the gearbox and the engine as the sparkplug was very oily after running it on pure petrol for a few minutes. The engine will start but if the throttle is pulled the engine stalls. Is there any history of leaks between engine and gearbox?