just had something like this happen to my 2000 trx350tm happen to me..cept is was alittle different..should be about the same problem though. ( my hurry up and ride job cost me putting the centrifugal clutch bearing in backwards )..lmfao..anyway..i can tell you to either check your clutch increase or decrease bolt/nut..or your one-way centrifugal clutch bearing is worn..and causing it to not work your clutch basket right...try adjusting your clutch free play first..see if that helps..if not..then your gonna have to tear your case off..and remove your centrifugal clutch..and inspect your one-way bearing.