Abstract: The present invention relates to an exhaust system for a combustion engine of a marine vessel. The exhaust system includes an exhaust system inlet configured to be coupled to an exhaust gas outlet of the marine engine, one or more exhaust system outlets, and an exhaust gas flow path extending from the inlet to the one or more exhaust system outlets and having a forward flow direction from the exhaust system inlet and a reverse flow direction extending from at least one of the one or more exhaust system outlets. The exhaust system further includes a flow redirection arrangement in the exhaust gas flow path for restricting a flow of liquid flowing in the reverse flow direction, the flow redirection arrangement comprising at least one flow redirection feature configured to redirect a first stream of the liquid toward the forward flow direction to collide with a second stream of the flow of liquid. The invention also relates to motor assemblies and marine vessels having such exhaust systems.

Abstract: A marine engine assembly is provided for propelling a marine vessel. The marine engine assembly includes an internal combustion engine configured to drive a propulsion arrangement, a turbocharger comprising a turbine portion having a turbine outlet, and a turbocharger exhaust conduit coupled to the turbine outlet. The turbocharger exhaust conduit acts as a primary support to the turbocharger within the marine engine assembly.

Abstract: A marine outboard motor for a marine vessel. The marine outboard motor includes: a housing comprising a chamber and at least one inlet arranged to be submerged, in use, into a body of water in which the marine outboard motor is operated, in order to draw water into the chamber; an engine assembly comprising an internal combustion engine; a drive shaft positioned in the housing, wherein the drive shaft is coupled to the internal combustion engine to drive a propulsion arrangement; a cooling system for cooling the internal combustion engine, the cooling system configured convey drawn water along a coolant flow path through the housing to deliver the drawn water to the internal combustion engine; and a sleeve by which the drive shaft is sealed from drawn water within the housing, the sleeve having first and second ends, wherein at least a part of the drive shaft is encased within the sleeve.

Abstract: A marine outboard motor having an internal combustion engine is provided. The internal combustion engine includes an engine block having at least one cylinder and a valve train comprising a cam, a valve assembly including a valve spring, a roller finger follower, and a pivot post. The pivot post extends from a fixed body of the engine block and defines a contact surface about which the roller finger follower pivots when deflected by the cam during use. The pivot post is moveable relative to the fixed body in a first longitudinal direction (A) against the action of the valve spring. A removable shim is disposed between the fixed body and a portion (182) of the pivot post to space the pivot post from the fixed body in the first longitudinal direction (A) and thereby reduce an amount of lash between the cam and the roller finger follower. The removable shim is dimensioned to fit at least partly around a shaft portion of the pivot post.

Abstract: A piston for an internal combustion engine is provided. The piston includes a piston body including an upper combustion surface, an annular side wall with a ring belt region, and a cooling gallery located within the piston body having a fluid inlet. A piston ring is located in a ring groove around the ring belt region and an alignment pin is secured in a hole in the piston side wall to restrict circumferential displacement of the piston ring. The piston body further includes a boss within the cooling gallery into which the hole and the alignment pin extend. The boss projects into the cooling gallery opposite the fluid inlet and is shaped to provide a flow splitter surface configured to divide cooling fluid flowing through the fluid inlet during use into first and second fluid flows and to direct the first and second fluid flows in opposite directions around the cooling gallery.

Abstract: A marine outboard motor is provided with an internal combustion engine comprising an engine block defining at least one cylinder, an air intake configured to deliver a flow of air to the at least one cylinder, a crankcase in which a crankshaft is mounted for rotation about a crankshaft axis which is substantially vertical when the marine outboard is vertical, and a crankcase ventilation system configured to vent blow-by gases from the crankcase and to supply vented blow-by gases to the air intake. The crankcase ventilation system comprises a lubricant separation chamber for separating lubricant from the blow-by gases. The lubricant separation chamber is defined by the crankcase and extends along the length of the crankcase substantially parallel to the crankshaft axis.

Abstract: A marine outboard motor for a marine vessel is provided. The marine outboard motor includes an internal combustion engine, a drive shaft configured to transmit a drive force from the internal combustion engine, a propeller shaft, and a drive transmission configured to transmit the drive force from the drive shaft to the propeller shaft. The motor also includes a lubrication system configured to convey lubricant along a lubricant flow path to lubricate one or both of the drive transmission and the drive shaft, and a lubricant filter provided along the lubricant flow path and configured to remove solid contaminants from the lubricant as it flows along the lubricant flow path. The lubricant filter is configured to be driven by the drive shaft.

Abstract: A port belt arrangement for use in a two-stroke internal combustion engine containing a pair of adjacent cylinders. The arrangement including a first hollow annulus defining a first annular channel, the first annular channel tapering in a radial direction, with increasing circumferential distance from a first port, an inner wall of the first annular channel having a second port, and a second hollow annulus defining a second annular channel, the second annular channel tapering in a radial direction, with increasing circumferential distance from a third port, an inner wall of the second annular channel having a fourth port, wherein the first hollow annulus and the second hollow annulus are joined together at a joining point located on each of their circumferences. The cross-sectional area of the first annular channel at the joining point is less than the cross-sectional area of the first annular channel at the point on the circumference of the first hollow annulus which is furthest from the joining point.

Abstract: A marine outboard motor is provided with a gear casing, a propeller shaft rotatable within the gear casing about a propeller shaft axis, a drive shaft having a drive gear, a clutch mechanism for selectively engaging the drive gear with the propeller shaft and a shift mechanism configured to operate the clutch mechanism. The shift mechanism comprises a support shaft which is fixed relative to the gear casing and which extends along or parallel with the propeller shaft axis, a shift shuttle which is slidable along the support shaft and is connected to a clutch member of the clutch mechanism, a shift finger pivotally mounted on the support shaft, and a shift rod coupled to the shift finger by a releasable coupling. The shift finger is configured to move the shift shuttle along the support shaft to operate the clutch member.

Abstract: A marine outboard motor is provided with an internal combustion engine comprising an engine block defining at least one cylinder, an air intake configured to deliver a flow of air to the at least one cylinder; and an air intake duct forming part of an air intake path for delivering the flow of air to the air intake. The engine further includes a flow sensing arrangement located in the air intake duct and comprising a flow meter configured to generate a signal indicative of a flow rate of the flow of air through the air intake duct, and a bluff body located in the air intake duct upstream of the flow meter, wherein the flow meter is a vortex shedding flow meter.

Abstract: The present invention relates to an exhaust system for a combustion engine of a marine vessel. The exhaust system includes an exhaust system inlet configured to be coupled to an exhaust gas outlet of the marine engine, one or more exhaust system outlets, and an exhaust gas flow path extending from the inlet to the one or more exhaust system outlets and having a forward flow direction from the exhaust system inlet and a reverse flow direction extending from at least one of the one or more exhaust system outlets. The exhaust system further includes a flow redirection arrangement in the exhaust gas flow path for restricting a flow of liquid flowing in the reverse flow direction, the flow redirection arrangement comprising at least one flow redirection feature configured to redirect a first stream of the liquid toward the forward flow direction to collide with a second stream of the flow of liquid. The invention also relates to motor assemblies and marine vessels having such exhaust systems.

Abstract: An internal combustion engine comprising at least one cylinder and a pair of opposed, reciprocating pistons within the cylinder forming a combustion chamber therebetween. The engine has at least one combustion igniter associated with the cylinder, a portion of the combustion igniter being exposed within the combustion chamber formed between the opposed pistons.

Abstract: The present invention relates to a drive system for outboard motors. The drive system comprises a combustion engine having a crankshaft adapted to rotate about a substantially vertical axis. The combustion engine further comprises a camshaft extending parallel to the vertical crankshaft. A high pressure fuel pump is provided for supplying high pressure fuels to the combustion cylinders. The high pressure fuel pump is directly driven by the camshaft.