01. This is HPI’s drop-in replacement 51mm big-bore throttle body for ’06-present cable-operated Harley-Davidsons (MSRP $695). The unit came with everything Matt needed to swap out his stock setup, including the throttle body and new flanges and gaskets. Matt also got some of HPI’s 5.3gps high-flow injectors (MSRP $180). HPI also offers Fly-by-Wire throttle body assemblies for late-model baggers.