crf help

[jedneck]

I am having problems with my crf cutting out. It was suckin the air filter shut so I made a cage for inside of it. I just put a hrc head pipe on it instead of a stock 450r head pipe. It has a stage 2 hot cam and a mikd port and polish also. I am running a 182 main jet, not sure where the needle clip is set. I haven't played with the jetting yet the guy I bought the motor from ran a mega bomb header and a fmf can. It runs great till about half throttle then falls flat on its face. If I up shift it will start pulling again. I think my intake duct is to restrictive. Does anybody have any idea's if I am right or not.

[toxicd]

sounds like you are either way too rich or way too lean on your jetting. have you done a plug chop to see which one is the case?? also make sure you have no intake leaks causing air to be sucked in past the air filter. not only would that cause performance problems, eventually you will suck in enough dirt to possibly destroy your motor.