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.

The invention relates to a boat with an electric drive that comprises electric components, especially an electric motor and an electric storage unit. The components are interconnected via an electric grid. At least one of the components is connected to the grid by means of a first connection means, the first connection means comprising first connection means main contacts for connecting the at least one component to the grid, and a second connection means being provided for connecting the electric storage unit to or disconnecting it from the grid. According to the invention, the first connection means comprises at least one pair of auxiliary contacts for connecting the at least one component to a monitoring line and said monitoring line is operatively connected to the second connection means.

A method of controlling steering loads on a marine propulsion system of a marine vessel is provided. The marine vessel has at least two sets of marine drives, each set having at least an inner marine drive and an outer marine drive, and a steer-by-wire steering actuator is associated with each set of marine drives. The method includes determining a maximum required actuator pressure on each steer-by-wire steering actuator, and determining a pressure reduction amount based on the maximum required actuator pressure. A link toe angle has been determined based on the pressure reduction amount. A mechanical link connecting each inner marine drive to the respective outer marine drive is adjusted to achieve the link toe angle.

An outboard-motor vibration-isolating cooler system method providing a retrofit substitute for the midsection and the lower unit of a standard outboard motor, having a substitute closed-loop cooling system with an exterior heat exchanger, a substitute oil reservoir, a substitute exhaust system, and a substitute propulsion system with an isolating power-take-off shaft, allowing an existing standard outboard-motor powerhead to be used in conditions not conducive to standard open-loop water cooling, such as shallow-water, muddy-water, obstructed-water, seawater, or corrosive-water conditions.

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.

A method for preserving electrical power in a marine vessel having a marine propulsion device. The method includes operating a variable operating device according to an original setting, measuring an actual system voltage for the marine propulsion device, and comparing the actual system voltage measured to a target system voltage. The method further includes adjusting the operation of the variable operating device from the original setting based on the comparison of the actual system voltage to the target system voltage, where adjusting the operation changes the electrical power usage in the marine propulsion device.

A system for suspending a lubricant in a marine propulsion device having a gearcase, the gearcase defining a gearset cavity for containing a propeller shaft gearset rotated by a driveshaft. The system includes a pump device configured to pump the lubricant away from the gearset cavity, and a reservoir located away from the gearset cavity and configured to receive the lubricant from the pump device. An input passage conveys the lubricant from the pump device to the reservoir, and an output passage conveys the lubricant from the reservoir to the gearset cavity. The reservoir is configured to retain at least 15% of the lubricant circulating between the gearset cavity and the reservoir.

A multi-purpose personal watercraft for deployment in different configurations as desired by a user. The multi-purpose personal watercraft comprises a base frame which forms a watercraft base which includes side extensions, an aft floor board, and a bow portion, as well as two opposing mirror image side floats with which the base frame is selectively integrated. When in place, the opposing side floats form the multi-purpose personal watercraft's U shaped hull and enable the selective attachment of a rudder assembly behind the multi-purpose personal watercraft's stern. With respect to propulsion, base frame is configured to enable the selective deployment of pedal propellers, a user's legs, or a trolling motor. A dual steering system enables the control of up to two discrete steering mechanisms from a single position on the watercraft.

A method of and an arrangement for improving the lubrication system of a propulsion device of a marine vessel are specifically applicable in removing water from the lubrication oil of various types of thrusters. An inert gas is arranged from an inert gas source to flow through a gas cavity in the lubrication system for flushing moist gas from the cavity.

A sonar transducer assembly is provided including a transducer configured to transmit one or more sonar beams into an underwater environment, a housing that holds the transducer, at least one electrical cable that enables electrical signals to be transmitted between the transducer and a computing device, and a conductive enclosure disposed around at least a portion of the transducer and electrically connected to a ground line of the electrical cable to create a shielded volume. The conductive enclosure reduces an electromagnetic field within the shielded volume.