Abstract: A jet pump assembly includes a marine engine, a jet drive and a shield adapted to be secured to a transom of a watercraft. The shield has arms to which the marine engine is secured and legs to which the jet drive is secured, the arms and legs extending in opposite directions. The shield has a flange adapted to be secured to the transom of the watercraft. The shield covers an opening in the transom through which the jet pump assembly is passed during assembly. A gasket between the shield and transom prevents water from entering the watercraft.

Abstract: A jet pump assembly includes a marine engine, a jet drive and a shield adapted to be secured to a transom of a watercraft. The shield has arms to which the marine engine is secured and legs to which an intake mount is secured. The jet drive is supported by the intake mount. The shield has at least one flange adapted to be secured to a middle toon of a pontoon boat. The shield covers an opening in the middle toon through which the marine engine is passed during assembly. A gasket between the shield and opening prevents water from entering the middle toon.

Abstract: A jet pump assembly includes a marine engine, a jet drive and a shield adapted to be secured to a transom of a watercraft. The shield has arms to which the marine engine is secured and legs to which the jet drive is secured, the arms and legs extending in opposite directions. The shield has a flange adapted to be secured to the transom of the watercraft. The shield covers an opening in the transom through which the jet pump assembly is passed during assembly. A gasket between the shield and transom prevents water from entering 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: An air intake and exhaust system for a marine engine having an intake manifold and an exhaust manifold includes an air compressor configured to compress ambient air into compressed air and a catalytic converter assembly configured to convert pollutants in an exhaust gas stream received from the exhaust manifold. The air compressor is configured to be fluidly coupled to the intake manifold of the engine for directing at least a first portion of the compressed air to the intake manifold of the engine. The air compressor is also selectively fluidly coupled to the catalytic converter assembly for selectively directing a second portion of the compressed air into the exhaust gas stream at a secondary air injection location at or upstream of the catalytic converter assembly.

Abstract: An air intake and exhaust system for a marine engine having an intake manifold and an exhaust manifold includes an air compressor configured to compress ambient air into compressed air and a catalytic converter assembly configured to convert pollutants in an exhaust gas stream received from the exhaust manifold. The air compressor is configured to be fluidly coupled to the intake manifold of the engine for directing at least a first portion of the compressed air to the intake manifold of the engine. The air compressor is also selectively fluidly coupled to the catalytic converter assembly for selectively directing a second portion of the compressed air into the exhaust gas stream at a secondary air injection location at or upstream of the catalytic converter assembly.

Abstract: An air intake and exhaust system for a marine engine having an intake manifold and an exhaust manifold includes an air compressor configured to compress ambient air into compressed air and a catalytic converter assembly configured to convert pollutants in an exhaust gas stream received from the exhaust manifold. The air compressor is configured to be fluidly coupled to the intake manifold of the engine for directing at least a first portion of the compressed air to the intake manifold of the engine. The air compressor is also selectively fluidly coupled to the catalytic converter assembly for selectively directing a second portion of the compressed air into the exhaust gas stream at a secondary air injection location at or upstream of the catalytic converter assembly.

Abstract: A heat exchange system for use on an engine-powered watercraft includes a liquid cooling system for cooling the engine using a first heat exchanger and a water heating system using a second heat exchanger for heating water. Raw water from an external water source is passed through each heat exchanger. Water used to cool the engine coolant inside the first heat exchanger exits the watercraft. Water heated by the second heat exchanger is passed to either an intake conduit or at least one onboard accessory system for flushing thereof to kill aquatic invasive species. A valve inside the second heat exchanger opens to release heated water when the heated water reaches a temperature of at least 140° F. Heated coolant from the first heat exchanger passes through the second heat exchanger to transfer heat to the water inside the second heat exchanger.

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: An air intake and exhaust system for a marine engine having an intake manifold and an exhaust manifold includes an air compressor configured to compress ambient air into compressed air and a catalytic converter assembly configured to convert pollutants in an exhaust gas stream received from the exhaust manifold. The air compressor is configured to be fluidly coupled to the intake manifold of the engine for directing at least a first portion of the compressed air to the intake manifold of the engine. The air compressor is also selectively fluidly coupled to the catalytic converter assembly for selectively directing a second portion of the compressed air into the exhaust gas stream at a secondary air injection location at or upstream of the catalytic converter assembly.

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 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 system for a marine exhaust system includes two riser conduits, each being connected to a Y-pipe at an outlet end. An inner tube of each riser conduit directs exhaust gases through a catalytic converter assembly and into the Y-pipe. An outer tube surrounds each inner tube to define a cooling liquid passage between the inner and outer tubes to direct cooling liquid into one of the inlets of the Y-pipe. A bellows couples one of the riser conduits to one of the inlets of the Y-pipe. Each bellows surrounds one of the inlets of the Y-pipe and one of the riser conduits. To minimize reversion, the inner tube of each of the riser conduits extends into one of the bellows further than the outer tube of the respective riser conduit.

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 riser conduits, each being connected to a Y-pipe at an outlet end. An inner tube of each riser conduit directs exhaust gases through a catalytic converter assembly and into the Y-pipe. An outer tube surrounds each inner tube to define a cooling liquid passage between the inner and outer tubes to direct cooling liquid into one of the inlets of the Y-pipe. A bellows couples one of the riser conduits to one of the inlets of the Y-pipe. Each bellows surrounds one of the inlets of the Y-pipe and one of the riser conduits. To minimize reversion, the inner tube of each of the riser conduits extends into one of the bellows further than the outer tube of the respective riser conduit.

Abstract: A heat exchange system for use on an engine-powered watercraft includes a liquid cooling system for cooling the engine using a first heat exchanger and a water heating system using a second heat exchanger for heating water. Raw water from an external water source is passed through each heat exchanger. Water used to cool the engine coolant inside the first heat exchanger exits the watercraft. Water heated by the second heat exchanger is passed to either an intake conduit or at least one onboard accessory system for flushing thereof to kill aquatic invasive species. A valve inside the second heat exchanger opens to release heated water when the heated water reaches a temperature of at least 140° F. Heated coolant from the first heat exchanger passes through the second heat exchanger to transfer heat to the water inside the second heat exchanger.

Abstract: A heat exchange system for use on an engine-powered watercraft includes a liquid cooling system for cooling the engine using a first heat exchanger and a water heating system using a second heat exchanger for heating water. Raw water from an external water source is passed through each heat exchanger. Water used to cool the engine coolant inside the first heat exchanger exits the watercraft. Water heated by the second heat exchanger is passed to either an intake conduit or at least one onboard accessory system for flushing thereof to kill aquatic invasive species. A valve inside the second heat exchanger opens to release heated water when the heated water reaches a temperature of at least 140° F. Heated coolant from the first heat exchanger passes through the second heat exchanger to transfer heat to the water inside the second heat exchanger.

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 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.