Patent ID: 7219643

Claim:
An internal combustion engine for a personal watercraft, wherein the personal watercraft comprises a jet propulsion pump and a body, the body including a hull and a deck, wherein the internal combustion engine is mounted in the body between the hull and the deck, and is provided to drive the jet propulsion pump, the deck being capable of supporting at least one rider thereon, the internal combustion engine comprising a dry sump oil system having an oil cooler, an oil thermostat, an upstream oil path which directs oil into the oil cooler, and a downstream oil path which receives oil discharged from the oil cooler, the internal combustion engine further comprising a bypass oil path connecting the upstream oil path and the downstream oil path independent of the oil cooler, said bypass oil path extending directly from the upstream oil path to the downstream oil path via a closed passage extending therebetween; wherein the oil thermostat is disposed in the upstream oil path, the oil thermostat capable of selectively directing oil to the oil cooler or to the bypass oil path, and of selectively switching the flow of lubricating oil therebetween, and wherein during engine operation, the oil thermostat directs oil to the bypass oil path when the temperature of the lubricating oil is below a predetermined temperature, and directs oil to the oil cooler when the temperature of the lubricating oil is equal to or above the predetermined temperature.