Abstract: A skateboard comprises a rider's platform having pairs of front and rear wheels mounted thereunder. Front wheels are mounted for limited universal movement relative to the platform whereas the rear wheels are mounted under the platform solely for vertical pivot movements about a pivot axis disposed in a vertically disposed plane which intersects the longitudinal axis of the skateboard. A bracket is attached to the rear wheel mounting and has a motor secured thereon for selectively driving only one of the rear wheels via a stepped-down drive train and a centrifugally actuated clutch. A normally open kill-switch is mounted on a throttle control adapted to be grasped by a rider whereby a magneto of the engine may be grounded to stop the engine when desired.