Abstract: A jet pump includes a propulsion system including an impeller coupled to a rotatable shaft configured to receive torque from an engine and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the exhaust system is separate from the propulsion system. The propulsion system includes a water intake configured to take in water from a body of water, the water intake including an intake grate and a base, and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the base of the water intake is configured to be coupled to an exterior surface of a hull of the watercraft.

Abstract: A jet pump includes a propulsion system including an impeller coupled to a rotatable shaft configured to receive torque from an engine and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the exhaust system is integrated with the propulsion system. In another embodiment, a jet pump includes a propulsion system including a water intake configured to take in water from a body of water, the water intake including an intake grate and an intake base, and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the intake base of the water intake is configured to be coupled to an exterior surface of a hull of the watercraft.

Abstract: A jet pump includes a propulsion system including an impeller coupled to a rotatable shaft configured to receive torque from an engine and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the exhaust system is separate from the propulsion system. The propulsion system includes a water intake configured to take in water from a body of water, the water intake including an intake grate and a base, and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the base of the water intake is configured to be coupled to an exterior surface of a hull of the watercraft.

Abstract: A jet pump includes a propulsion system including an impeller coupled to a rotatable shaft configured to receive torque from an engine and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the exhaust system is integrated with the propulsion system. In another embodiment, a jet pump includes a propulsion system including a water intake configured to take in water from a body of water, the water intake including an intake grate and an intake base, and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the intake base of the water intake is configured to be coupled to an exterior surface of a hull of the watercraft.

Abstract: A jet pump includes a propulsion system including an impeller coupled to a rotatable shaft configured to receive torque from an engine and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the exhaust system is integrated with the propulsion system. In another embodiment, a jet pump includes a propulsion system including a water intake configured to take in water from a body of water, the water intake including an intake grate and an intake base, and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the intake base of the water intake is configured to be coupled to an exterior surface of a hull of the watercraft.

Abstract: A jet pump includes a propulsion system including an impeller coupled to a rotatable shaft configured to receive torque from an engine and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the exhaust system is integrated with the propulsion system. In another embodiment, a jet pump includes a propulsion system including a water intake configured to take in water from a body of water, the water intake including an intake grate and an intake base, and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the intake base of the water intake is configured to be coupled to an exterior surface of a hull of the watercraft.

Abstract: A water pump for a marine engine includes a cap covering an internal cavity of the pump's housing when the pump is operating. The cap functions as a tool to remove a damaged or worn impeller from inside the internal cavity. A threaded hub of the cap engages internal threads of the impeller to assist a user in removing the impeller for replacement. A cap lock ring threaded onto the pump housing retains the cap over the internal cavity. A rotatable drive shaft has splines which mate with a splined portion of the impeller to rotate the impeller. The cap lock ring is disengaged from the housing and the cap removed to enable a person to use the threaded hub of the cap to remove the impeller.

Abstract: A jet pump includes a propulsion system including an impeller coupled to a rotatable shaft configured to receive torque from an engine and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the exhaust system is integrated with the propulsion system. In another embodiment, a jet pump includes a propulsion system including a water intake configured to take in water from a body of water, the water intake including an intake grate and an intake base, and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the intake base of the water intake is configured to be coupled to an exterior surface of a hull of the watercraft.

Abstract: A jet pump includes a propulsion system including an impeller coupled to a rotatable shaft configured to receive torque from an engine and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the exhaust system is integrated with the propulsion system. In another embodiment, a jet pump includes a propulsion system including a water intake configured to take in water from a body of water, the water intake including an intake grate and an intake base, and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the intake base of the water intake is configured to be coupled to an exterior surface of a hull of the watercraft.

Abstract: A jet pump includes a propulsion system including an impeller coupled to a rotatable shaft configured to receive torque from an engine and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the exhaust system is integrated with the propulsion system. In another embodiment, a jet pump includes a propulsion system including a water intake configured to take in water from a body of water, the water intake including an intake grate and an intake base, and an exhaust system including an exhaust flow path configured to direct exhaust from the engine to an exterior of the watercraft, wherein the intake base of the water intake is configured to be coupled to an exterior surface of a hull of the watercraft.

Abstract: A heat exchanger for a marine engine has a housing with an internal cavity. Twisted tubes snake back and forth inside the cavity and carry a first fluid to cool a second engine cooling fluid flowing through the cavity. Each of the twisted tubes has a plurality of ridges to increase the surface area of the tube exposed to the second fluid. Dividers inside the cavity direct the flow of the second fluid through the cavity. The housing may have a removable cover to access the housing cavity.

Abstract: An exhaust conduit for a marine exhaust system includes an inlet end portion connectable to an exhaust manifold, an outlet end portion that directs exhaust gases toward an exhaust system outlet, a catalytic converter assembly arranged between the inlet and outlet end portions, and inner and outer tubes. The inner tube directs exhaust gases from the exhaust manifold to the catalytic converter assembly, and the outer tube surrounds the inner tube to define a cooling liquid passage between the inner and outer tubes. A flange is secured to the inner and outer tubes at inlet ends thereof, the flange being connectable to an outlet of the exhaust manifold. The inner tube has a uniform diameter between the flange and the catalytic converter assembly, and is welded to the flange independently of the outer tube. First and second welds join the inner and outer tubes to the flange at radially inner and outer faces, respectively, of a flange rim.

Abstract: A water pump for a marine engine includes a cap covering an internal cavity of the pump's housing when the pump is operating. The cap functions as a tool to remove a damaged or worn impeller from inside the internal cavity. A threaded hub of the cap engages internal threads of the impeller to assist a user in removing the impeller for replacement. A cap lock ring threaded onto the pump housing retains the cap over the internal cavity. A rotatable drive shaft has splines which mate with a splined portion of the impeller to rotate the impeller. The cap lock ring is disengaged from the housing and the cap removed to enable a person to use the threaded hub of the cap to remove the impeller.

Abstract: An exhaust system for a marine exhaust system includes two identical liquid-cooled exhaust manifolds. Each exhaust manifold has an outlet portion adapted to receive and retain a catalytic converter. Liquid cooled first and second risers are secured to the first and second exhaust manifolds. Bypass hoses enable fluid to pass from each exhaust manifold to its coupled riser. At the outlet of each riser, the cooling fluid and exhaust gas mix in a Y-pipe to create a combined flow. An exhaust outlet conduit downstream of the Y-pipe receives the combined flow and discharges the combined flow.

Abstract: A strainer assembly for a marine engine has a housing with an internal cavity. The housing has a threaded inlet end, an outlet and a flush port. A removable cover assembly covers the threaded inlet end and may be removed to allow a strainer to be removed from inside the housing and cleaned. The flush port may be closed with a plug and opened to allow a threaded end of a garden hose to be attached to the flush port for cleaning the engine.

Abstract: An exhaust system for a marine exhaust system includes two identical liquid-cooled exhaust manifolds. Each exhaust manifold has an outlet portion adapted to receive and retain a catalytic converter. Liquid cooled first and second risers are secured to the first and second exhaust manifolds. Bypass hoses enable fluid to pass from each exhaust manifold to its coupled riser. At the outlet of each riser, the cooling fluid and exhaust gas mix in a Y-pipe to create a combined flow. An exhaust outlet conduit downstream of the Y-pipe receives the combined flow and discharges the combined flow.

Abstract: An exhaust conduit for a marine exhaust system includes an inlet end portion connectable to an exhaust manifold, an outlet end portion that directs exhaust gases toward an exhaust system outlet, a catalytic converter assembly arranged between the inlet and outlet end portions, and inner and outer tubes. The inner tube directs exhaust gases from the exhaust manifold to the catalytic converter assembly, and the outer tube surrounds the inner tube to define a cooling liquid passage between the inner and outer tubes. A flange is secured to the inner and outer tubes at inlet ends thereof, the flange being connectable to an outlet of the exhaust manifold. The inner tube has a uniform diameter between the flange and the catalytic converter assembly, and is welded to the flange independently of the outer tube. First and second welds join the inner and outer tubes to the flange at radially inner and outer faces, respectively, of a flange rim.

Abstract: An exhaust muffler for a marine exhaust system includes an inner conduit, an outer conduit surrounding the inner conduit and a plurality of spiral baffles extending radially outward from the inner conduit to the outer conduit. The outer conduit has end portions connectable to exhaust conduits for directing a mixture of fluid and exhaust gas towards an exhaust system outlet. The mixture flows through the inner conduit and through a cooling passage between the conduits. One or more of the spiral baffles has multiple openings for improving the mixing process of exhaust gas and fluid.

Abstract: An exhaust conduit for a marine exhaust system includes an inlet end portion connectable to an exhaust manifold, an outlet end portion that directs exhaust gases toward an exhaust system outlet, a catalytic converter assembly arranged between the inlet and outlet end portions, and inner and outer tubes. The inner tube directs exhaust gases from the exhaust manifold to the catalytic converter assembly, and the outer tube surrounds the inner tube to define a cooling liquid passage between the inner and outer tubes. A flange is secured to the inner and outer tubes at inlet ends thereof, the flange being connectable to an outlet of the exhaust manifold. The inner tube has a uniform diameter between the flange and the catalytic converter assembly, and is welded to the flange independently of the outer tube. First and second welds join the inner and outer tubes to the flange at radially inner and outer faces, respectively, of a flange rim.

Abstract: A heat exchanger for a marine engine has a housing with an internal cavity. Twisted tubes snake back and forth inside the cavity and carry a first fluid to cool a second engine cooling fluid flowing through the cavity. Each of the twisted tubes has a plurality of ridges to increase the surface area of the tube exposed to the second fluid. Dividers inside the cavity direct the flow of the second fluid through the cavity. The housing may have a removable cover to access the housing cavity.