Abstract: A friction-bearing assembly is disclosed which comprises a friction bearing and a shaft, the friction-bearing assembly includes a first bearing gap defined between the sliding surface of the friction bearing and the outer surface of the shaft, and a second bearing gap defined between the inside surface of the friction bearing and the outer surface of the shaft, the second bearing gap being at least 10% wider relative to the first bearing gap, to a maximum of 1 mm. The second bearing gap is positioned adjacent the first bearing gap and located in-between a lubricating oil supply and the first bearing gap such that the first bearing gap is supplied with lubricating oil through the second bearing gap.

Abstract: An internal combustion engine has a power unit case having a crankcase, a first housing flange and a second housing flange. The crankshaft axis and the output shaft axis define a reference plane. An oil pump has an oil pump shaft, having an oil pump shaft axis, disposed at least partially in an oil pump chamber. A normal projection of the oil pump shaft axis onto the reference plane is located between the crankshaft axis and the output shaft axis. A first housing cover is mounted to the first housing flange on a first side of the power unit case. A separate oil pump cover is mounted to the second housing flange on the first side of the power unit case to close the oil pump chamber.

Abstract: An internal combustion engine has an engine casing. A shaft, having a shaft axis, is disposed in the engine casing. At least one bearing supports the shaft in the engine casing. A separator wheel is disposed on the shaft for rotation therewith. The separator wheel has a first opening in fluid communication with the crankcase, a second opening, and a channel extending radially from the second opening to the first opening relative to the shaft axis. A suction tube is permanently affixed to a portion of the engine casing. An end of the suction tube has a unitary abutment surface. A gasket is disposed between the unitary abutment surface and the second opening of separator wheel. The gasket is also disposed at least in part on a separating plane of the engine casing.

Abstract: A Crankshaft bearing assembly for supporting a crankshaft for rotation about a crankshaft axis within an engine having an aluminum engine block, the crankshaft bearing assembly including at least one crankshaft bearing divided into a first half and a second half, the first half being integral with the engine block, and the second half being a bearing cap connectable to the engine block. The bearing cap is made of an aluminum alloy having a tensile strength higher than the tensile strength of the engine block.

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: The four stroke internal engine having an air intake system connected to the cylinder head and operatively connected to the intake passageway. The air intake system includes an air intake manifold having symmetrical construction with a central air passageway extending between a first end and a second end. At least one passageway extends from the central air passageway to a free end, which is operatively coupled to the intake passageway. The air intake system is usable for both a supercharged and normally aspirated engines.

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 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: The four stroke internal engine having an air intake system connected to the cylinder head and operatively connected to the intake passageway. The air intake system includes an air intake manifold having symmetrical construction with a central air passageway extending between a first end and a second end. At least one passageway extends from the central air passageway to a free end, which is operatively coupled to the intake passageway. The air intake system is usable for both a supercharged and normally aspirated engines.