A portable propulsion system for a watercraft may include a shaft, a propeller, an outer casing, and a flexible strap. The shaft may have a prop end section, a drive end section, and a rotational axis extending from the prop end section to the drive end section. The propeller may be connected to the prop end section of the shaft. The drive end section may be configured for removable connection to a driver for rotation of the propeller via rotation of the shaft about the rotational axis to propel the watercraft. The outer casing may be disposed around the shaft. The flexible strap may have first and second end sections connected to the outer casing in respective first and second regions.

An outboard propulsion system comprising an engine configured to receive oil; an oil pan configured to receive oil from the engine; and an oil reservoir configured to receive oil from the oil pan and provide oil to the engine, in use.

An outboard propulsion system comprising an engine configured to receive oil; an oil pan configured to receive oil from the engine; and an oil reservoir configured to receive oil from the oil pan and provide oil to the engine, in use.

An engine propelling apparatus has power generating transmitting portion provided below a power generating portion, a propelling force generating portion provided adjacent to the power transmitting portion, and height adjustment mechanisms. The power generating portion includes an engine with a crankshaft arranged horizontal and substantially parallel to the front-rear longitudinal direction of a boat. A power transmission mechanism forms a linear power transmission route extending from the vicinity of a front end of the crankshaft to the vicinity of a front end of the propelling force generating portion. The propelling force generating portion includes a propeller shaft extending rearwards from the power transmitting portion, and a propeller at a rear portion of the propeller shaft. The height adjustment mechanisms vary inclination or height of all or a part of the engine propelling apparatus with respect to the boat to thereby vary height of the propeller with respect to the boat.

An engine propelling apparatus has power generating transmitting portion provided below a power generating portion, a propelling force generating portion provided adjacent to the power transmitting portion, and height adjustment mechanisms. The power generating portion includes an engine with a crankshaft arranged horizontal and substantially parallel to the front-rear longitudinal direction of a boat. A power transmission mechanism forms a linear power transmission route extending from the vicinity of a front end of the crankshaft to the vicinity of a front end of the propelling force generating portion. The propelling force generating portion includes a propeller shaft extending rearwards from the power transmitting portion, and a propeller at a rear portion of the propeller shaft. The height adjustment mechanisms vary inclination or height of all or a part of the engine propelling apparatus with respect to the boat to thereby vary height of the propeller with respect to the boat.

Shock absorbing hub assemblies and methods of making the same for marine propulsion devices having a propeller shaft and propeller. The assembly has an adapter component having an inner bore that engages the propeller shaft's splined outer surface and having a body with axially extending engagement surfaces on one end and an elastic hub component on an opposite end. The elastic hub component has planar outer engagement surfaces that abut corresponding inner engagement surfaces on the propeller hub's inner bore. Upon initial propeller shaft rotation, the elastic hub component deflects and allows the adapter component to rotationally travel relative to the propeller hub while not rotating the propeller hub. Upon further rotation, the adapter component's axially extending engagement surfaces engage with the propeller hub to rotate the propeller hub. The elastic hub component has a spring rate small enough to reduce clutch rattle yet large enough to isolate transmission shift clunk.

A propeller propulsion system for a watercraft includes at least one electric motor and a propeller which can be driven by the electric motor. The propeller is a surface piercing propeller. The propulsion system includes a box-like body having a side wall on which the electric motor is fixed and a cover part on which an outdrive of the surface piercing propeller is applied. The side wall and the cover part include holes through which a shaft of the motor and a shaft of the outdrive respectively pass. The box-like body includes means for transmission of motion from the drive shaft to the outdrive shaft, and the propulsion system includes means for fixing the box-like body to a transom of the watercraft.

An outboard motor includes: an upper case supported on a hull; a lower case pivotably supported on the upper case; a first drive source disposed within the upper case; a planetary gear mechanism connected to the first drive source via an upper drive shaft; a propeller shaft connected to the planetary gear mechanism via a lower drive shaft; and a second drive source that provides the lower case with a torque. The planetary gear mechanism includes a sun gear, a planetary carrier supporting planetary gears and connected to an upper end of the lower drive shaft, and an internal gear. One of the sun gear and the internal gear is connected to the lower end of the upper drive shaft, and the other is connected to the lower case to provide the lower case with a torque in a direction opposite to a rotation direction of the lower drive shaft.

An outboard motor includes: an upper case supported on a hull; a lower case pivotably supported on the upper case; a first drive source disposed within the upper case; a planetary gear mechanism connected to the first drive source via an upper drive shaft; a propeller shaft connected to the planetary gear mechanism via a lower drive shaft; and a second drive source that provides the lower case with a torque. The planetary gear mechanism includes a sun gear, a planetary carrier supporting planetary gears and connected to an upper end of the lower drive shaft, and an internal gear. One of the sun gear and the internal gear is connected to the lower end of the upper drive shaft, and the other is connected to the lower case to provide the lower case with a torque in a direction opposite to a rotation direction of the lower drive shaft.

A portable propulsion system for a watercraft may include a shaft, a propeller, an outer casing, and a flexible strap. The shaft may have a prop end section, a drive end section, and a rotational axis extending from the prop end section to the drive end section. The propeller may be connected to the prop end section of the shaft. The drive end section may be configured for removable connection to a driver for rotation of the propeller via rotation of the shaft about the rotational axis to propel the watercraft. The outer casing may be disposed around the shaft. The flexible strap may have first and second end sections connected to the outer casing in respective first and second regions.