Abstract: Several embodiments of water cooled motorcycles incorporating an improved compact arrangement wherein the components do not interfere with each other or the rider's stance. In each embodiment the engine cooling system includes a heat exchanger that is positioned on one side of the frame adjacent the down tube. An exhaust system is incorporated that includes an expansion chamber that is disposed on the opposite side of the down tube and which is connected to the engine by a U-shaped section of sufficient length so as to provide the desired exhaust performance. In some embodiments the cooling capacity is increased by employing multiple radiator sections. In each embodiment the side-to-side balance of the motorcycle is maintained by the positioning and sizing of the components.