i have got C20 LET engine, and its all going wrong ! it started about a month ago to cut the engine when you hit the throttle hard and then after a few seconds it would fire up again a little strange but still driveable. but now it wont even go above 40 mph ! it just constantly cuts out then 5 ar 6 second later fires up again. there is no management light and no fault code any one got a good idea?