A jet propelled watercraft includes a watercraft body, an engine housed in the watercraft body, a jet propulsion unit that suctions and jets water with a drive force of the engine, a first exhaust pipe connected to an exhaust port of the engine, and a catalyst storage connected to the first exhaust pipe, wherein the first exhaust pipe and the catalyst storage are integral and unitary with each other.

A marine ducted propeller mass flux propulsion system that comprises: an intake section; an impeller/confusor/stator section; a discharge section; a passage extending from an intake opening of the intake section to an outlet of the discharge section, the passage having a length and an axial cross-sectional area, the passage capable of creating a flow path for a water stream on a volumetric basis; and a plurality of internal working parts, the plurality of internal working parts being at least partially accommodated within the passage, wherein the axial cross-sectional area of the passage is increased and decreased throughout the length of the passage to accommodate a volumetric mass of the plurality of the internal working parts while maintaining a constant water volume from the intake opening of the intake section to the outlet of the discharge section.

An engine system and method of operating the same includes a two stroke engine, an exhaust manifold coupled to the two-stroke engine, a tuned pipe coupled to the exhaust manifold coupled to the exhaust manifold, a stinger pipe coupled to the tuned pipe, a silencer coupled to the tuned pipe and an exhaust pipe, and an exhaust bypass valve. Exhaust gases are directed from the two stroke engine through an exhaust manifold and through a tuned pipe. An opening of the exhaust bypass valve is changed to redirect exhaust gases away from the tuned pipe to change a pressure within the tuned pipe. In response to changing the opening of the exhaust bypass valve, the airflow through the engine is changed.

An exhaust system for a watercraft with an engine includes an upstream exhaust pipe including an end portion with an outlet, a water lock including an inner space accommodating the end portion, a downstream exhaust pipe connected to the water lock, and a flow direction diverter, such as a baffle. The upstream exhaust pipe guides exhaust gas from the engine to the end portion. The inner space of the water lock receives the exhaust gas from the outlet of the end portion. The downstream exhaust pipe exhausts the exhaust gas from the inner space to an outside of the watercraft body. The flow direction diverter changes a flow direction of the exhaust gas at the outlet to a cross direction which intersects a pipe axis of the end portion.

An exhaust system for a watercraft with an engine includes an upstream exhaust pipe including an end portion with an outlet, a water lock including an inner space accommodating the end portion, a downstream exhaust pipe connected to the water lock, and a flow direction diverter, such as a baffle. The upstream exhaust pipe guides exhaust gas from the engine to the end portion. The inner space of the water lock receives the exhaust gas from the outlet of the end portion. The downstream exhaust pipe exhausts the exhaust gas from the inner space to an outside of the watercraft body. The flow direction diverter changes a flow direction of the exhaust gas at the outlet to a cross direction which intersects a pipe axis of the end portion.

A marine ducted propeller mass flux propulsion system that comprises: an intake section; an impeller/confusor/stator section; a discharge section; a passage extending from an intake opening of the intake section to an outlet of the discharge section, the passage having a length and an axial cross-sectional area, the passage capable of creating a flow path for a water stream on a volumetric basis; and a plurality of internal working parts, the plurality of internal working parts being at least partially accommodated within the passage, wherein the axial cross-sectional area of the passage is increased and decreased throughout the length of the passage to accommodate a volumetric mass of the plurality of the internal working parts while maintaining a constant water volume from the intake opening of the intake section to the outlet of the discharge section.

An engine system and method of operating the same includes a two stroke engine, an exhaust manifold coupled to the two-stroke engine, a tuned pipe coupled to the exhaust manifold coupled to the exhaust manifold, a stinger pipe coupled to the tuned pipe, a silencer coupled to the tuned pipe and an exhaust pipe, and an exhaust bypass valve. Exhaust gases are directed from the two stroke engine through an exhaust manifold and through a tuned pipe. An opening of the exhaust bypass valve is changed to redirect exhaust gases away from the tuned pipe to change a pressure within the tuned pipe. In response to changing the opening of the exhaust bypass valve, the airflow through the engine is changed.

A marine ducted propeller mass flux propulsion system that comprises: an intake section; an impeller/confusor/stator section; a discharge section; a passage extending from an intake opening of the intake section to an outlet of the discharge section, the passage having a length and an axial cross-sectional area, the passage capable of creating a flow path for a water stream on a volumetric basis; and a plurality of internal working parts, the plurality of internal working parts being at least partially accommodated within the passage, wherein the axial cross-sectional area of the passage is increased and decreased throughout the length of the passage to accommodate a volumetric mass of the plurality of the internal working parts while maintaining a constant water volume from the intake opening of the intake section to the outlet of the discharge section.

A jet propelled watercraft includes a watercraft body, an engine housed in the watercraft body, a jet propulsion unit that suctions and jets water with a drive force of the engine, a first exhaust pipe connected to an exhaust port of the engine, and a catalyst storage connected to the first exhaust pipe, wherein the first exhaust pipe and the catalyst storage are integral and unitary with each other.

An embodiment of an exhaust handling system for a marine vessel includes a cap connected to a top end portion of an exhaust stack of the marine vessel to form an enclosure at least partially surrounding an outlet of an exhaust pipe extending through the exhaust stack. In addition, the exhaust handling system includes a collection pipe in fluid communication with the cap such that the collection pipe is to receive exhaust from the enclosure, and a coupling connected to the collection pipe that is to connect to an exhaust cleaning assembly. The exhaust cleaning system includes a tank to receive the exhaust. The cap at least partially defines a first flow path for the exhaust that extends from the enclosure to the atmosphere. The collection pipe at least partially defines a second flow path for the exhaust that extends from the enclosure to the coupling via the collection pipe.