I'm running the ducar 212 completely stock except a fuel pump. On raceday I could only get 4300 rpms out of it even with a low gearing(18-65). I ran the feature with a 18-58, and i ran better, but still 4300 rpms. Back at home I hooked the throttle straight to the butterfly, still 4300 on a road test. On the stand I can get 5200 max. It runs smooth always, sounds good. What am I missing?