SAVE $500! The PGM-FI fuel injection system provides crisp and accurate throttle response.Color outside the lines. A down-flow airbox and narrow 30 mm high-velocity funnels, route intake airflow in as straight a line as possible. The PGM-FI fuel injection system operates with info from 4 separate throttle body sensors on 32 mm throttle bores for crisp and accurate throttle response. Careful siting and angling of the throttle bodies allows a narrow frame width, improving manageability for the rider.