The invention provides an internal combustion engine comprising a piston mounted for reciprocating linear motion within a cylinder along a cylinder axis. The piston is coupled to an output shaft by a power transfer assembly arranged to convert linear motion of the piston to rotary motion of the output shaft. The piston has a first head moveable within a first chamber and a second head opposite the first head and moveable within a second chamber. The power transfer assembly has a lubrication system for lubricating moving components of the power transfer assembly. The lubrication system is sealed from the first chamber and the second chamber to prevent the passage of fluid from the lubrication system into the first chamber and the second chamber.

A steering apparatus for an outboard motor includes a steering mechanism including a guide arranged forward relative to and parallel or substantially parallel to a tilt shaft, a moving body that is rotatably coupled to an arm through a first pivot shaft parallel or substantially parallel to the tilt shaft and movable along the guide, and a support bracket that supports the guide such that the guide rotates about a second pivot shaft parallel or substantially parallel to the tilt shaft and offset relative to the tilt shaft.

A steering apparatus for an outboard motor includes a steering mechanism including a guide arranged forward relative to and parallel or substantially parallel to a tilt shaft, a moving body that is rotatably coupled to an arm through a first pivot shaft parallel or substantially parallel to the tilt shaft and movable along the guide, and a support bracket that supports the guide such that the guide rotates about a second pivot shaft parallel or substantially parallel to the tilt shaft and offset relative to the tilt shaft.

An outboard motor mounting apparatus for outboard motors that control the outboard motor propeller thrust line angle of attack through a larger range than is currently available in practice today, including afterplanes (hydrodynamic lifting surfaces) in order to create boat stern lift. The afterplanes move to provide lift with a trimmable hinged portion in combination with movement of the outboard motor propeller thrust line.

An outboard motor mounting apparatus for outboard motors that control the outboard motor propeller thrust line angle of attack through a larger range than is currently available in practice today, including afterplanes (hydrodynamic lifting surfaces) in order to create boat stern lift. The afterplanes move to provide lift with a trimmable hinged portion in combination with movement of the outboard motor propeller thrust line.

A method for positioning two or more trimmable marine propulsion devices coupled to a transom of a marine vessel includes identifying two propulsion devices located one on each of a port side and a starboard side of a centerline of the transom and spaced symmetrically with respect to the centerline. The two propulsion devices are defined as a first set and are associated with a first target trim position. The method also includes defining a second set of propulsion devices and associating the second set with a second target trim position. When in auto-trim mode, each propulsion device in a set of propulsion devices is actuated to its target trim position only if the actual trim positions of all propulsion devices in the set differ from the target trim position by at least a given amount. The propulsion devices may be actuated individually in response to a user sync command.

A method for positioning two or more trimmable marine propulsion devices coupled to a transom of a marine vessel includes identifying two propulsion devices located one on each of a port side and a starboard side of a centerline of the transom and spaced symmetrically with respect to the centerline. The two propulsion devices are defined as a first set and are associated with a first target trim position. The method also includes defining a second set of propulsion devices and associating the second set with a second target trim position. When in auto-trim mode, each propulsion device in a set of propulsion devices is actuated to its target trim position only if the actual trim positions of all propulsion devices in the set differ from the target trim position by at least a given amount. The propulsion devices may be actuated individually in response to a user sync command.

Embodiments of outboard motors and related systems and components thereof, as well as arrangements of marine vessels implementing same, as well as related methods of operation, use, assembly, and manufacture, and related improvements, are disclosed herein. In at least some embodiments, the outboard motor includes a cowling system in which at least one divider portion separates an interior region into first and second portion, with the transmission and engine respectively being situated in the first and second portions, respectively. Additionally, in at least some embodiments, the outboard motor includes a water pump system in which a water pump is integrated with the transmission. Further, in at least some embodiments, the outboard motor includes a fuel vaporization suppression feature, or an oil tank feature that allows for desirable oil drainage from the engine of the outboard motor particularly when the outboard motor is in particular (e.g., storage) positions.

Embodiments of outboard motors and related systems and components thereof, as well as arrangements of marine vessels implementing same, as well as related methods of operation, use, assembly, and manufacture, and related improvements, are disclosed herein. In at least some embodiments, the outboard motor includes a cowling system in which at least one divider portion separates an interior region into first and second portion, with the transmission and engine respectively being situated in the first and second portions, respectively. Additionally, in at least some embodiments, the outboard motor includes a water pump system in which a water pump is integrated with the transmission. Further, in at least some embodiments, the outboard motor includes a fuel vaporization suppression feature, or an oil tank feature that allows for desirable oil drainage from the engine of the outboard motor particularly when the outboard motor is in particular (e.g., storage) positions.

There are provided a piston rod having one end portion attached to a marine vessel propulsion machine main body; an inner cylinder; an inner piston mounted in the other end portion of the piston rod, dividing a space in the inner cylinder into a fourth chamber and a fifth chamber; an outer cylinder accommodating the inner cylinder therein; a cap covering an opening portion of one end portion of the outer cylinder; and an outer piston dividing a space in the outer cylinder into a second chamber and a first chamber, is formed with a through hole that allows the fourth chamber and the second chamber to communicate with each other, comes into contact with the cap to divide the third space into an inner space on a more inner side than the through hole and an outer space on a more outer side than the inner space.