Slayer........it sounds like to me , there is a slight air leak , and i bet i know where it's at. I had the same thing happen to my engine , but it was from losing control and slamming it into a fire hydrant at about 35MPH!! What had happened was right where the carb attaches to the block , (where the stem for the high speed needle is) , there was a super small seperation between the brass fitting and the casting of the actuall block of the motor. I took the motor off the buggy , took the pipe off , put a little fuel in the carb and turned over by hand. I then blocked both the exaust and the intake with my finger's and tried to turn the motor over. What i saw was some really small little air bubble coming from that seperation. I took the motor ( RB C4) to the hobby shop and got a new carb ordered for it.


the Carb it'self wasn't damaged , but the stem for the high speed was , and i didn't want to take a chance and try to rig another one back onto that carb just in case. After i got the new carb..........she fired right up!! Well............hope that gives you another option , instead of going out and buying a whole new motor.



JEFFRO