I was wondering if anyone had any idea why my 97 king quad dies out after it warms up. It runs great until it warms up. then it sputters out and dies. It has been at the local repair ship for 4 weeks and he has checked alot of stuff. The carb, valve adjustment, vacum and air lines, compression ect. the head also seems to have a small leak?? any infomation in the source of this problem would help

Thanks.