wont go

Can't seem to figure out why my 2016 RTX will only go 66mph at 12k rpm. Mods are a few from Schmidt Brothers as well as a 136" 1.5" free ride. I have Chris' stage 2 clutch kit. Stock gearing (18/41) with 9 tooth drivers. Tested by 2 different riders, talked to Chris multiple times. NEED HELP...