An outboard motor having an internal combustion engine that causes rotation of a driveshaft, a planetary transmission that operatively connects the driveshaft to a transmission output shaft, a band brake configured to shift the planetary transmission amongst a forward gear, neutral gear and reverse gear, a hydraulic actuator is configured to actuate the band brake, and a cooling water circuit that extends adjacent to the hydraulic actuator so that the hydraulic actuator exchanges heat with cooling water in the cooling water circuit.

An outboard propulsion system comprising: a first portion for attachment to a boat comprising a stern, the first portion comprising an engine including a crankshaft; and a second portion comprising at least one propeller shaft having a longitudinal axis along the elongate length of the at least one propeller shaft, wherein the at least one propeller shaft is operably connected to the crankshaft via at least one drive shaft configured to transmit motive power therebetween, wherein the at least one drive shaft comprises a drop shaft and wherein the drop shaft is substantially perpendicular to the at least one propeller shaft, wherein the second portion is configured to pivot relative to the first portion about a steering axis, wherein the steering axis intersects the longitudinal axis of the at least one propeller shaft at an obtuse angle, wherein the first portion and second portion are configured to tilt together about a single axis of rotation substantially parallel to the stern of the boat, and wherein the first portion is fixed about a substantially vertical axis.

A reciprocating internal combustion engine includes at least one piston, which is operatively connected by two connecting rods having two crankshafts rotating in opposite directions and running parallel to each other, which crankshafts are oriented in an upright manner to a horizontal water line of a boat, and an internal combustion engine housing of the internal combustion engine is composed of at least a cylinder crank housing and a cylinder head, having inlet and outlet valves, and is bounded by an upper end face and a bottom end face. To optimize the internal combustion engine, a joint ventilation system has an oil separating device provided with an oil pre-separator and a main oil separator, via which, when operating the internal combustion engine, a mixture of oil and leaking gas, resulting in a crankcase of the cylinder crank housing, reaches, by way of a discharge line extending adjacent to the upper end face, the oil pre-separator, from where the mixture of oil and leaking gas is led into the main oil separator and there is separated into the components of oil and leaking gas. The oil flows into an oil pan connecting at the bottom end face and the leaking gas near the upper end face flows into an intake system of the internal combustion engine.

A forward/backward switching mechanism having an intermediate gear supported by an intermediate shaft perpendicular to a drive shaft is interposed between first and second input shafts. A clutch body is a dog clutch having upper and lower locking dogs. As the dog clutch moves along an axial direction of the second input shaft and is engaged with upper or lower gears, rotation of the first input shaft is forwardly or reversely transmitted to the second input shaft.

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.

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 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 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 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.