Flying Horse 48cc/66cc/80cc 2-Stroke Motorized Bicycle Engine Clutch Actuator Bearing &ndash; Gas Bike Clutch Ball Bearing The Clutch Actuator Bearing helps engage and disengage 2-stroke 48cc and 66/80cc motorized bicycle engine kits in conjunction with the bucking bar Installation is simple: remove the drive sprocket case cover and in the center of the drive sprocket will be the bucking bar. Remove that bucking bar, tip the engine over slightly to take the bearing out, and replace with the new bearing. Close the case, and you're good to go Note: Be sure the clutch actuator bearing is within the motor before installing, as the motor will not engage or disengage without it and the bucking bar