Abstract: A marine engine has an internal combustion engine; an exhaust conduit that conveys exhaust gas from the internal combustion engine; a cooling water sprayer that sprays a first flow of cooling water into the exhaust conduit; and a cooling water jacket that conveys a second flow of cooling water alongside the exhaust conduit so that the second flow of cooling water cools the exhaust conduit. The first flow of cooling water and at least part of the second flow of cooling water are merged and then sprayed together into the exhaust conduit via the cooling water sprayer.

Abstract: Wrought structural components, including drive shaft housing components for marine outboard engines are disclosed. The components have a first face, a second face substantially parallel with respect to the first face, and a sidewall. The sidewall includes a first sidewall and a second sidewall each extending from the first face to the second face. The wrought structural components are constructed of a wrought aluminum alloy and are essentially free of draft angles. The alloys may have low silicon content, low copper content, high plane strain fracture toughness, high tensile ductility, and/or a low porosity. The wrought structural components may be prepared by extrusion.

Abstract: A marine propulsion device includes an internal combustion engine; an axially elongated exhaust conduit that conveys exhaust gas from the upstream internal combustion engine to a downstream outlet; a cooling water sprayer that is configured to spray a flow of cooling water radially outwardly toward an inner diameter of the axially elongated exhaust conduit; a temperature sensor located downstream of the cooling water sprayer and configured to sense temperature of the exhaust gas and cooling water; and a controller configured to identify a fault condition associated with the cooling water sprayer based on the temperature of the exhaust gas and cooling water.