Water preclusion device for marine engine

A watercraft comprising a hull, an engine supported by the hull, the engine including an engine body defining at least one combustion chamber, and an exhaust system comprising an exhaust gas passage extending from the engine body to a valve, the valve being configured to be controlled by pressure in a cylinder port passage, the cylinder port passage configured to communicate cylinder pressure from the engine body to the valve, the valve mounted at least partially in the exhaust gas passage and configured to be movable between a first position in which the exhaust gas passage is open and a second position in which the exhaust gas passage is closed and all fluid communication between the combustion chamber and the atmosphere through the exhaust gas passage is stopped, wherein the valve is mounted to move such that positive pressure in the cylinder port passage up stream from the valve imparts a force onto the valve to move the valve in a direction towards exhaust gas flow.

A method of preventing water from flowing upstream in an exhaust system for a watercraft having an engine including an engine body defining at least one combustion chamber, a first exhaust conduit extending from the engine body to the atmosphere, and a valve mounted at least partially in the first exhaust conduit and configured to be movable between a closed position where all fluid communication between the combustion chamber and the atmosphere through any portion of the first exhaust conduit stops and an open position, the method comprising guiding pressure from the combustion chamber to a valve controller through a second conduit, moving the valve to the open position with pressure in the second conduit.

A watercraft comprising a hull defining an engine compartment, an engine positioned within the engine compartment, the engine comprising at least one cylinder including at least one cylinder port, a combustion chamber, and an exhaust system comprising a first exhaust conduit extending from the cylinder port to the atmosphere, the first exhaust conduit including at least one exhaust valve configured to prevent the invasion of water into the engine, the cylinder port being in communication with the exhaust valve, the exhaust valve being configured to move between a closed position where all fluid communication between the cylinder port and the atmosphere through any portion of the exhaust system stops and an open position, a pressure conduit communicating with the cylinder port for operating the exhaust valve while the engine is running.

A watercraft comprising a hull defining an engine compartment, an engine positioned within the engine compartment, the engine comprising at least one cylinder including at least one cylinder port, a combustion chamber, and an exhaust system including at least one exhaust valve configured to prevent the invasion of water into the engine, the cylinder port being in communication with the exhaust valve, the exhaust valve being configured to move between a closed position where all fluid communication between the combustion chamber and the atmosphere through the exhaust system stops and an open position, a pressure conduit communicating with the cylinder port for operating the exhaust valve while the engine is running, wherein the exhaust valve is activated by a linkage.

A watercraft comprising a hull defining an engine compartment, an engine positioned within the engine compartment, the engine comprising at least one cylinder including at least one cylinder port, a combustion chamber, and an exhaust system including at least one exhaust valve configured to prevent the invasion of water into the engine, the cylinder port being in communication with the exhaust valve, the exhaust valve being configured to move between a closed position where all fluid communication between the combustion chamber and the atmosphere through the exhaust system stops and an open position, a pressure conduit communicating with the cylinder port for operating the exhaust valve while the engine is running, wherein the exhaust valve is activated directly by an exhaust valve piston.

A watercraft comprising a hull defining an engine compartment, an engine positioned within the engine compartment, the engine comprising at least one cylinder including at least one cylinder port, an exhaust system including at least one exhaust valve configured to prevent the invasion of water into the engine, the cylinder port being in communication with the exhaust valve, a pressure conduit communicating with the cylinder port operating the exhaust valve while the engine is running, the pressure conduit incorporating an expansion chamber, the expansion chamber being configured to smooth pressure fluctuations in the pressure conduit.