Engine cooling system configuration, and personal watercraft incorporating same

An internal combustion engine for 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 an internal combustion engine for driving the jet propulsion pump, wherein

• the internal combustion engine comprises a crankcase, a cylinder head disposed on an upper surface of the crankcase, and a water-cooled oil cooler for cooling lubricant oil,
• a cooling water intake passage directs cooling water from at a positive pressure side of the jet propulsion pump to the oil cooler,
• the oil cooler comprises an oil cooler housing which receives cooling water from the cooling water intake passage,
• the oil cooler disposed within the oil cooler housing, and wherein
• the oil cooler is disposed on an upper portion of the engine adjacent to the cylinder head so as to reside above the crankcase, and the cooling water intake passage is disposed below the oil cooler and connects to a lower side of the oil cooler.

A personal watercraft, comprising a vessel body, a jet propulsion pump housed within the vessel body, a cooling water intake port in communication with the jet propulsion pump, and an internal combustion engine mounted inside of the vessel body 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, and
• wherein the cooling water intake passage is positioned below the location where the cooling water enters the oil cooler housing.