My ´06(my ´05 was replaced due to factory defects) is fully de-restricted with the factory available kit-manifold, jet, rollers. I also removed the variator spacer as well as the airbox restriction and exhaust restriction(brass plug in end of pipe). I still only get the almost exact same performance you do(42-45mph on the flats).I have a boost bottle coming for it but I suspect that will only help with acceleration; not top speed. I may try to go with even lighter rollers(any suggestions on weight?) as I am topping out at 8500rpm right now...seems like it could handle at least 10k based on how it feels at 8500. Once I hear some feedback on 70cc kits I´ll probably wind up doing that.