Patent ID: 6347969
Filing Date: 2002-02-19
Classification: B63H,F01P,F02B

Abstract:
An outboard motor having a water propulsion device and an internal combustion engine positioned in a cowling, the engine having an engine body assembly defining at least one cylinder, an air delivery system for delivering at least an air charge to said cylinder and an exhaust system for discharging a burnt charge from said cylinder to the atmosphere, said exhaust system including an exhaust passage for collecting the exhaust gasses from said cylinder, said engine further comprising an output shaft arranged to drive said water propulsion device, and a cooling system for said engine including a coolant delivery mechanism driven by said engine for drawing water from a body of water in which said outboard motor is operating and returning the drawn water back to the body of water, said cooling system comprising a first coolant path for cooling said cylinder and a second coolant path for cooling primarily said exhaust passage, said delivery mechanism arranged to deliver coolant through said second coolant path and directly therefrom to a coolant drain, said delivery mechanism arranged to deliver coolant through said first coolant path to said coolant drain, and means for controlling the flow of coolant from said engine through said first and second coolant paths comprising first and second control valves disposed at respective downstream ends of said first and said second coolant paths for controlling the respective flow therethrough independently of fluid pressure.