Abstract: A watercraft includes a hull, an engine compartment defined at least in part by the hull, an engine disposed in the engine compartment, an air intake conduit fluidly connected to the engine, an air filter fluidly connected to the air intake conduit, and a shroud connected to an inlet end of the air intake conduit located in the engine compartment. The shroud has an open end and a closed end. The open end is open to flow of air therethrough and the closed end is closed to flow of air therethrough. The shroud has a sidewall extending between the closed and open ends. The shroud is oriented such that the open end is disposed rearward of the closed end. Noise exiting the inlet end of the air intake conduit and the air filter is reflected generally rearward by the shroud. An engine assembly for a watercraft is also disclosed.

Abstract: A watercraft includes a hull, an engine compartment defined at least in part by the hull, an engine disposed in the engine compartment, an air intake conduit fluidly connected to the engine, an air filter fluidly connected to the air intake conduit, and a shroud connected to an inlet end of the air intake conduit located in the engine compartment. The shroud has an open end and a closed end. The open end is open to flow of air therethrough and the closed end is closed to flow of air therethrough. The shroud has a sidewall extending between the closed and open ends. The shroud is oriented such that the open end is disposed rearward of the closed end. Noise exiting the inlet end of the air intake conduit and the air filter is reflected generally rearward by the shroud. An engine assembly for a watercraft is also disclosed.

Abstract: An inlet grate for a water jet propulsion system to be used in a watercraft has a water passage having an inlet defined by a forward and a rearward area with respect to the watercraft. The inlet grate comprises a first end portion adapted to be connected to the forward area of the inlet and a second end portion adapted to be connected to the rearward area of the inlet as well as at least one elongated member extending from the first end portion toward the second end portion. The inlet grate also comprises at least one deflector having a forward end and a rearward end, the forward end being adjacent to the first end portion of the inlet grate.

Abstract: An inlet grate for a water jet propulsion system to be used in a watercraft has a water passage having an inlet defined by a forward and a rearward area with respect to the watercraft. The inlet grate comprises a first end portion adapted to be connected to the forward area of the inlet and a second end portion adapted to be connected to the rearward area of the inlet as well as at least one elongated member extending from the first end portion toward the second end portion. The inlet grate also comprises at least one deflector having a forward end and a rearward end, the forward end being adjacent to the first end portion of the inlet grate.

Abstract: An inlet grate cleaning system for a water jet propulsion system to be used in a watercraft. The water jet propulsion system has a water passage, the water passage has an inlet and the inlet has a forward area and a rearward area with respect to the watercraft. The inlet grate cleaning system comprises a pump and at least one water intake fluidly connected to the pump. At least one water outlet is also fluidly connected to the pump. The pump is adapted for pumping water from the at least one water intake to the at least one water outlet to create at least one jet of water. The at least one water outlet is positioned so as to direct the at least one jet of water toward an inlet grate.

Abstract: An inlet grate for a water jet propulsion system to be used in a watercraft has a water passage having an inlet defined by a forward and a rearward area with respect to the watercraft. The inlet grate comprises a first end portion adapted to be connected to the forward area of the inlet and a second end portion adapted to be connected to the rearward area of the inlet as well as at least one elongated member extending from the first end portion toward the second end portion. The inlet grate also comprises at least one deflector having a forward end and a rearward end, the forward end being adjacent to the first end portion of the inlet grate.

Abstract: The present invention provides a jet pump assembly that includes a rotatable shaft adapted to be operationally coupled to a power source. An impeller is operationally connected to the rotatable shaft. A housing surrounds at least a portion of the rotatable shaft operationally coupled to the impeller. In addition, a single bearing is disposed between the housing and the rotatable shaft, permitting rotation of the rotatable shaft therein. The bearing has at least an inner race operationally coupled to the rotatable shaft and an outer race operationally coupled to the housing. The bearing also includes at least two sets of rolling components disposed, side-by-side between the inner and outer races, permitting rotation of the inner and outer races with respect to one another.

Abstract: A watercraft, equipped with a jet propulsion system with improved efficiency of operation is disclosed. Structures are disposed within a water passage of the jet propulsion system at a position upstream of the jet propulsion unit that modulate the amount of water that is allowed to pass through the water passage. The structures can be a flexible fluid filled bag, an adjustable ride plate, and an additional water passage. Each of the structures allow a greater amount of water into the water passage during acceleration than during constant speed travel of the watercraft.

Abstract: The invention is directed to a thick stator vane that effects continuous acceleration of the water stream within the jet pump, a non-uniform spacing of stator vanes or impeller blades to reduce noise output of the jet pump during operation, and a coupling structure positioned between the impeller and engine that prevents transfer of axial thrust to the engine caused by jet pump failure.

Abstract: A watercraft, equipped with a jet propulsion system with improved efficiency of operation is disclosed. Structures are disposed within a water passage of the jet propulsion system at a position upstream of the jet propulsion unit that modulate the amount of water that is allowed to pass through the water passage. The structures can be a flexible fluid filled bag, an adjustable ride plate, and an additional water passage. Each of the structures allow a greater amount of water into the water passage during acceleration than during constant speed travel of the watercraft.

Abstract: The invention is directed to a thick stator vane that effects continuous acceleration of the water stream within the jet pump, a non-uniform spacing of stator vanes or impeller blades to reduce noise output of the jet pump during operation, and a coupling structure positioned between the impeller and engine that prevents transfer of axial thrust to the engine caused by jet pump failure.

Abstract: A watercraft is equipped with a jet propulsion system that has improved output propulsion and energy efficiency. Vanes are disposed within the water passage that extends through the jet propulsion system. The vanes are disposed upstream of an impeller. The vanes substantially correct the rotational motion of the water, which is created by the drive shaft. This assists in minimizing swirl created when the watercraft is turned. This also helps to improve the operational efficiency of the jet propulsion unit.

Abstract: The present invention provides a jet pump assembly that includes a rotatable shaft adapted to be operationally coupled to a power source. An impeller is operationally connected to the rotatable shaft. A housing surrounds at least a portion of the rotatable shaft operationally coupled to the impeller. In addition, a single bearing is disposed between the housing and the rotatable shaft, permitting rotation of the rotatable shaft therein. The bearing has at least an inner race operationally coupled to the rotatable shaft and an outer race operationally coupled to the housing. The bearing also includes at least two sets of rolling components disposed, side-by-side between the inner and outer races, permitting rotation of the inner and outer races with respect to one another.