An outboard motor includes a gear housing configured to rotatably house a propeller shaft that transmits a rotative power output from an engine to a propeller device. The gear housing includes a torpedo shape portion and a strut portion. The torpedo shape portion has a shape tapered toward a front side, and a shape biased upward toward the front side. The strut portion is disposed on an upper side of the torpedo shape portion. An outer peripheral surface of the torpedo shape portion is smoothly coupled to an outer peripheral surface of the strut portion via first to third curved surfaces. The first to third curved surfaces are each a curved surface inclined rearward and downward, a curved surface parallel to a front-rear direction, or a curved surface constituted of a part inclined rearward and downward and a part parallel to the front-rear direction.

A method for shifting a multi-speed transmission of a marine propulsion device between a first gear and a second gear each configured to transmit torque from a powerhead to a transmission output shaft. The method includes determining an actual power level requested for operating the marine propulsion device and measuring a transmission output shaft speed in which the transmission output shaft is rotating. The method further includes comparing the actual power level to a shift threshold, the shift threshold corresponding to expected power levels for operating the marine propulsion device as a function of the transmission output shaft speed of the transmission output shaft. The method further includes controlling the multi-speed transmission to shift when the actual power is outside the shift threshold.

An outboard motor includes an engine having an output portion. A lower gear mechanism drives a propeller disposed below the engine. A transmission includes an input shaft that transmits power from the output portion to the transmission. An output shaft transmits power from the transmission to the lower gear mechanism. A reverse idler shaft is parallel to an intermediate shaft. A forward clutch is disposed on one of the input and intermediate shafts and connects and disconnects power from the input shaft to the intermediate shaft. A reverse clutch is disposed on the intermediate shaft and connects and disconnects power transmission from the input shaft to the intermediate shaft. Power of the input shaft is transmitted to the output shaft via the forward clutch and the intermediate shaft and is transmitted to the output shaft via the reverse idler shaft, the reverse clutch, and the intermediate shaft.

A marine propulsion system for a marine vessel has a drive unit comprising an upper part and a lower part, the upper part being pivotable in relation to the marine vessel and the lower part is rotatably connected with the upper part, the lower part comprises one or more propellers. An input unit receives an activation message indicative of an operation mode for the drive unit. A control unit is connected with the drive unit and the input unit. The control unit controls the drive unit on basis of the activation message received from the input unit. The control unit, in response to receiving a beach mode activation message from the input unit, rotates the lower part to a position with the one or more propellers facing aft in relation to the marine vessel, and/or wherein the control unit, in response to receiving a swim mode activation message from the input unit, rotates the lower part to a position with the one or more propellers at least facing forward in a position of minimum 90 degrees compared to an aft facing position of the one or more propellers.

A drive assembly for a marine propeller drive unit has two concentric drive shafts for carrying a respective propeller. A space between the drive shafts is lubricated with liquid lubricant pumped into the space by a pump. The outermost drive shaft is provided with at least one protrusion protruding radially inwards from an inner surface of the outer drive shaft. The inlet of the secondary fluid channel is provided in said at least one protrusion at a first radial level offset radially inwards from the inner surface of the outer drive shaft such that liquid lubricant at said first radial level is able to lubricate bearings between the outermost drive shaft and the innermost drive shaft.

A marine propeller propulsion unit has a compound planetary gear for driving a propeller, a propulsion motor for driving the compound planetary gear, and a housing for enclosing the propulsion motor and the compound planetary gear. The compound planetary gear comprises a sun gear, a ring gear, a planet carrier, a first planet gear and a second planet gear. The radius of the second planet gear exceeds the radius of the first planet gear and the first and second planet gears are rotationally fixed to one another. The ring gear meshes with the first planet gear and the sun gear meshes with the second planet gear. The sun gear is adapted to be connected to the propulsion motor and the ring gear is adapted to be connected to the propeller.

An outboard motor includes a power source disposed, a propeller shaft, a drive shaft, a gear mechanism, a lower case having an internal space in which gear oil is stored, a gear oil gauge configured to check a level or a state of the gear oil stored in the internal space, a gauge mounting hole provided configured to removably mount the gear oil gauge to the lower case such that one end side of the gear oil gauge is immersed in the gear oil stored in the internal space, a gauge insertion portion configured to insert the gear oil gauge into the gauge mounting hole, an oil supply and discharge passage provided in the lower case, and a pump connecting portion configured to connect a pump. The gauge insertion portion and the pump connecting portion are arranged side by side.

A duo propeller disclosed having a forward propeller having increased loading distribution and high swirl near the tip. The duo propeller has an aft propeller with a more optimal loading distribution that can cancel the high tip swirl from the forward propeller. The duo-propeller an enhanced ability for the aft propeller to capture the energy lost to the swirling flow of the forward propeller's outflow.

An outboard motor includes a case having a gear chamber, a drive shaft arrangement hole, and a propeller shaft arrangement hole, a drive shaft, a propeller shaft, a drive gear, a driven gear, a gear position setting member provided in front of the driven gear in the case and configured to set a position of the driven gear in a front-rear direction, and a screw mechanism configured to move the gear position setting member in the front-rear direction when the gear position setting member is rotated about an axis of the gear position setting member. The screw mechanism includes a first screw provided in the case and a second screw provided on the gear position setting member and configured to be screwed with the first screw.

A hybrid ship propulsion machine includes an internal-combustion-drive propulsion part and an electric propulsion part. The electric propulsion part is attached to a first housing part of the internal-combustion-drive propulsion part, and is disposed at a position higher than an anti-cavitation plate of the internal-combustion-drive propulsion part such that a second propeller of the electric propulsion part sinks below a water surface during low-speed movement, which is not a planing state of a ship, and the second propeller comes out of the water surface during planing of the ship.