Outboard motor with dual cooling system

摘要

An outboard motor including a propulsion unit connected to a boat attachment element for providing vertical and horizontal swinging movement of the propulsion unit relative to the boat, which propulsion unit includes a rotary internal combustion engine including a first housing assembly comprising wall surfaces defining aligned first and second trochoid shaped rotor cavities and additional wall surfaces defining a first water jacket system adjacent to the first and second rotor cavities and having inlet and outlet ports, together with a second housing assembly comprising wall surfaces defining aligned third and fourth trochoid shaped rotor cavities and additional wall surfaces defining a second water jacket system adjacent to the third and fourth rotor cavities and having inlet and outlet ports, bolts securing together the first and second housing assemblies, a lower unit rigidly supporting the engine and including a propeller rotatably supported by the lower unit and operably connected to the engine, a water pump driven by the engine and having an inlet communicating with the water, and a water conduit communicating between the pump and separately with each of the first and second water jacket system inlet ports.