Patent ID: 7219644

Claim:
A cooling system for an internal combustion engine in a personal watercraft wherein the personal watercraft comprises a jet propulsion pump, a cooling water intake port in communication with the jet propulsion pump, and the internal combustion engine for driving the jet propulsion pump, wherein the internal combustion engine comprises a water-cooled oil cooler for cooling lubricant oil, wherein a cooling water intake passage directs cooling water from a positive pressure side of the jet propulsion pump to the oil cooler, wherein the oil cooler comprises an oil cooler housing which receives flowing cooling water taken from the cooling water intake port at a positive pressure side of said jet propulsion pump and directed through the cooling water intake passage, the cooling water entering the oil cooler housing at a lower end of the oil cooler housing, and being discharged from an upper end of the oil cooler housing, wherein the cooling water intake passage is positioned below a cooling water inflow port of the oil cooler housing where the cooling water enters the oil cooler housing; and wherein the cooling system is configured to naturally discharge water from the oil cooler housing, via the cooling water intake passage, due to gravity flow when the personal watercraft is pulled on land.