Internal combustion engine having an improved oil cooling structure, and personal watercraft incorporating same

An internal combustion engine for a personal watercraft, wherein

• the internal combustion engine comprises 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, and wherein
• the oil thermostat is disposed in the upstream oil path, the thermostat being 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
• 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 at or above the predetermined temperature,
• the internal combustion engine further comprising a low-pressure oil switch and a high-pressure oil switch, wherein
• the low-pressure oil switch is provided in the bypass oil path;
• and
• the high-pressure oil switch is provided in the downstream oil path.

A personal watercraft, comprising a jet propulsion pump, a body comprising a hull and a deck, and an internal combustion engine,

• wherein the internal combustion engine drives the jet propulsion pump and is housed in the body between the hull and the deck, the deck being capable of supporting at least one rider thereon,
• the internal combustion engine comprising 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,
• wherein the oil thermostat is disposed in the upstream oil path, the 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 exceeds the predetermined temperature.