I just bought this bike. It idles perfectly and runs great at higher RPM's. It runs very rough just off idle to about mid throttle. Took the carb off and cleaned the pilot (ran a small wire through it). Everything looks pretty clean. The plug looks a little black, but swapped it with the plug in our CRF80 and nothing changes. I've had the carb off twice, for it surely seems like a fuel issue. Anyone have any other ideas? I thought I understood these bikes!