D391 motor upgrade for Regen systems. You can expect up to 21 MPH (48V, 3340RPM) with this motor and can be used with existing controller. The Regen system can be identified by the cart slowing going downhill even with the accelerator pushed down. If you have an electric rocker arm type forward and reverse switch, it will not have a capped computer port on the underside of the switch. Please call if you have any questions.