An outboard motor for a marine vessel application, transmission devices for such an outboard motor, and related methods of making, operating, and modifying attributes of same, are disclosed herein. In at least one embodiment, the motor includes a horizontal-crankshaft engine in an upper portion of the motor, positioned substantially above a trimming axis of the motor. In at least another embodiment, first, second and third transmission devices are employed to transmit rotational power from the engine to propeller(s). In at least a further embodiment, the motor is made to include a rigid interior assembly formed by the engine, multiple transmission devices, and a further structural component. In further embodiments, the motor includes numerous cooling, exhaust, and/or oil system components, and/or other transmission features. In at least some additional embodiments, a transmission device of the motor is configured to facilitate gear ratio variation and/or includes an integrated oil pump.

A marine drive has an internal combustion engine that rotates a propulsor shaft that is operatively coupled to a propulsor to impart a propulsive thrust in water. The marine drive has a gearcase housing having an upper portion above a lower portion, the lower portion supporting the propulsor shaft. An exhaust passage in the gearcase housing is configured to convey exhaust gas from the internal combustion engine. An exhaust outlet on the upper portion of the gearcase housing is configured to discharge the exhaust gas from the exhaust passage to the water. The exhaust outlet faces the propulsor so that the exhaust gas is discharged into the water and towards the propulsor so as to aerate the water encountered by the propulsor.

An outboard motor and methods of use thereof in general, includes a powerhead removeably affixed to the transom of a boat, and a gear case rotationally connected to a propeller shaft, the outboard motor including a telescopic drive shaft, the telescopic drive shaft having a first drive shaft section rotationally connected to the motor and a second drive shaft section rotationally connected to the gear case, and a telescopic drive shaft housing, the telescopic drive shaft housing configured to support the telescopic drive shaft internally therethrough, whereby the telescopic drive shaft and the telescopic drive shaft housing are configured to provide depth adjustment for the gear case and the propeller shaft, and thus enable the propeller to be raised and lowered during propulsion to improve propulsion efficiency.

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.

An outboard motor includes an electric motor including an output shaft extending in an upper-lower direction, a first helical gear including a first gear shaft extending in the upper-lower direction and including a first end connected to the output shaft of the electric motor, a first bearing to support the first end of the first gear shaft, a second bearing to support a second end of the first gear shaft, a second helical gear including a second gear shaft extending in the upper-lower direction and meshing with the first helical gear, and a case accommodating at least the first helical gear, the first bearing, and the second bearing. At least one of the first bearing or the second bearing defines a fixing mechanism to fix the first gear shaft at a predetermined position in the upper-lower direction with respect to the case when the first and second helical gears rotate.

An outboard motor includes an electric motor including an output shaft extending in an upper-lower direction, a gearing connected to the output shaft of the electric motor and including gears to rotate around a rotation shafts extending in the upper-lower direction, and a housing chamber to accommodate the gearing and oil. The housing chamber includes a peripheral wall extending around one of the gears. The peripheral wall includes a sloped portion between the one gear and the peripheral wall that is inclined upward along a rotating direction of the gear.

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.

Weed-trimmer outboard motor attachment has a lower shaft housing with a proximal coupling to correspondingly mate and engage a distal mid-shaft coupling of an upper part of a motorized weed-trimming device having a motor and a shaft that rotate a number of rotations per minute when operating; a distal termination thereto, which includes a propeller; and a rotation speed reduction unit to reduce a number of rotations of the propeller in relation to the number of rotations of the motor of the motorized weed-trimming device. The attachment can be assembled with the weed-trimming device to provide an outboard motor. A mount for mounting the weed-trimmer outboard motor to a boat can be provided as well.

A marine drive has an internal combustion engine that rotates a propulsor shaft that is operatively coupled to a propulsor to impart a propulsive thrust in water. The marine drive has a gearcase housing having an upper portion above a lower portion, the lower portion supporting the propulsor shaft. An exhaust passage in the gearcase housing is configured to convey exhaust gas from the internal combustion engine. An exhaust outlet on the upper portion of the gearcase housing is configured to discharge the exhaust gas from the exhaust passage to the water. The exhaust outlet faces the propulsor so that the exhaust gas is discharged into the water and towards the propulsor so as to aerate the water encountered by the propulsor.

An outboard motor having an upper cowling that covers an internal combustion engine, a driveshaft housing located below the upper cowling that covers a driveshaft that is rotated by the internal combustion engine, a transmission housing that is located below the driveshaft housing and covers a transmission that is operably connected to the driveshaft, and a lower gearcase that is located below the transmission housing and covers a set of angle gears that operably connect the transmission to a propulsor for imparting a propulsive force in a body of water.