I have a buddy who has a 02 yz426f and he was having problems with it bogging down when he would give it some throttle. After checking the carb he finally broke down and took it to the local shop. $300.00 later they are telling him he needs a CDI box and a throttle positioning sensor and its going to cost him another $300.00 or so. Has anyone had this problem before, does this sound right? I figure they could have maybe started there and saved him a couple of hours of labor charges.