Abstract: A personal watercraft is disclosed with a hull, a seating assembly, and a four stroke internal combustion engine below the seating assembly. The engine has at least one intake valve for each of the combustion cylinder chambers, at least one exhaust valve for each of the combustion cylinder chambers, and a valve actuation assembly located in a cylinder head for operating the intake and exhaust valves. At least one air intake passageway is operatively coupled to the combustion cylinder chambers through the intake valves. An air intake manifold is connected to the cylinder head and operatively connected to the at least one air intake passageway. The engine also has a supercharger for boosting air to the air intake manifold. The watercraft also includes a propulsion unit, operatively coupled to the crankshaft, which is located on one end of the two ends of the crankcase.

Abstract: A combined flame arrester and intercooler for cooling intake gas for an internal combustion engine is disclosed. The intercooler comprises an elongated body having a longitudinal axis. The elongated body has a central passageway that extends substantially parallel to the longitudinal axis. An inlet opening is located on one end of the elongated body such that the intake gas enters the central passageway though the inlet opening. The intercooler further includes a plurality of cooling tubes forming at least a portion of the elongated body. The plurality of tubes substantially surround the central passageway. Each of the cooling tubes is spaced from an adjacent cooling tube such that an air flow path is formed there between. The intake gas is cooled by flowing past the cooling tubes. Preferably, the intake gas flows along the central passageway in the elongated body and radially outward therefrom through the air flow path between the cooling tubes.

Abstract: A roll-over valve for a blow-by gas circulation system of an engine includes a piston slidably mounted within a valve housing. A lateral inlet opening and an outlet opening are disposed in the valve housing. When the valve is upright, fluid flows freely from the inlet opening to the outlet opening through the valve housing. When the valve overturns, the piston moves axially within the valve housing under the force of gravity into a roll-over position. When the piston is in the roll-over position, it blocks the fluid path between the inlet and outlet lines to close the valve. The inlet opening is positioned such that pressure in the inlet opening does not impede the movement of the piston. An air bleed passage fluidly connects portions of the valve housing that are above and below the piston and dampens movement of the piston within the valve housing.

Abstract: A combined flame arrester and intercooler for cooling intake gas for an internal combustion engine is disclosed. The intercooler comprises an elongated body having a longitudinal axis. The elongated body has a central passageway that extends substantially parallel to the longitudinal axis. An inlet opening is located on one end of the elongated body such that the intake gas enters the central passageway though the inlet opening. The intercooler further includes a plurality of cooling tubes forming at least a portion of the elongated body. The plurality of tubes substantially surround the central passageway. Each of the cooling tubes is spaced from an adjacent cooling tube such that an air flow path is formed there between. The intake gas is cooled by flowing past the cooling tubes. Preferably, the intake gas flows along the central passageway in the elongated body and radially outward therefrom through the air flow path between the cooling tubes.

Abstract: An apparatus and method are provided for selectively preventing fluid from flowing through a fluid path when a vehicle is in a predetermined orientation. When an orientation sensor signals to a controller that the vehicle is inverted, the controller closes a valve to prevent fluid from flowing therethrough. If the fluid path is part of an open-loop oil system, closing the valve may prevent oil in the oil system from leaking into the ambient environment when the vehicle flips over. Similarly, if the fluid path is part of an exhaust system for an engine of a watercraft, closing the valve may prevent water from entering the exhaust system and/or the engine when the watercraft flips over. Alternatively, the controller may alert an operator that a vehicle has been uprighted in an incorrect direction.

Abstract: A personal watercraft is disclosed with a hull, a seating assembly, and a four stroke internal combustion engine below the seating assembly. The engine has at least one intake valve for each of the combustion cylinder chambers, at least one exhaust valve for each of the combustion cylinder chambers, and a valve actuation assembly located in a cylinder head for operating the intake and exhaust valves. At least one air intake passageway is operatively coupled to the combustion cylinder chambers through the intake valves. An air intake manifold is connected to the cylinder head and operatively connected to the at least one air intake passageway. The engine also has a supercharger for boosting air to the air intake manifold. The watercraft also includes a propulsion unit, operatively coupled to the crankshaft, which is located on one end of the two ends of the crankcase.

Abstract: A four stroke internal combustion engine is disclosed having a power take off housing located at one end of the engine. A crankshaft is operatively connected to a drive shaft and the cam shaft within the power take off housing. Furthermore, the crankshaft is operatively coupled within the power take off housing to at least one of a generator, an engine starting mechanism, a balance shaft, and a supercharger.

Abstract: A supercharged four stroke internal combustion engine. The engine includes a power take off housing located on one end of the crankcase. A supercharger for boosting air intake to an air intake manifold is mounted to the power take off and operatively connected to the crank shaft within the power take off housing. A personal watercraft having a supercharged engine is also disclosed.

Abstract: An apparatus and method are provided for selectively preventing fluid from flowing through a fluid path when a vehicle is in a predetermined orientation. When an orientation sensor signals to a controller that the vehicle is inverted, the controller closes a valve to prevent fluid from flowing therethrough. If the fluid path is part of an open-loop oil system, closing the valve may prevent oil in the oil system from leaking into the ambient environment when the vehicle flips over. Similarly, if the fluid path is part of an exhaust system for an engine of a watercraft, closing the valve may prevent water from entering the exhaust system and/or the engine when the watercraft flips over. Alternatively, the controller may alert an operator that a vehicle has been uprighted in an incorrect direction.

Abstract: A supercharged four stroke internal combustion engine. The engine includes a power take off housing located on one end of the crankcase. A supercharger for boosting air intake to an air intake manifold is mounted to the power take off and operatively connected to the crank shaft within the power take off housing. A personal watercraft having a supercharged engine is also disclosed.

Abstract: A four stroke internal combustion engine is disclosed having a power take off housing located at one end of the engine. A crankshaft is operatively connected to a drive shaft and the cam shaft within the power take off housing. Furthermore, the crankshaft is operatively coupled within the power take off housing to at least one of a generator, an engine starting mechanism, a balance shaft, and a supercharger.