An outboard motor includes an engine, a propeller shaft that rotates together with a propeller and extends in a forward-rearward direction, and a lower case that houses the propeller shaft. The lower case includes a front case and a rear case separate from the front case and positioned rearward of the front case, and the front case and the rear case are assembled to each other.

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.

Provided herein is a marine propulsion apparatus including a prime mover having a drive shaft, a cowling enclosing the prime mover, first and second struts affixed to the cowling, where each of the struts have a leading portion, an interior belt void, and a trailing portion. The apparatus further includes a lower unit coupled to the distal ends of the struts, a sprocket rotatably disposed within the lower unit, a shaft rotatably coupled to the sprocket, a belt rotatably coupling the drive shaft to the sprocket, such that a first portion of the belt is disposed within the interior belt void of the first strut and a second portion of the belt is disposed within the interior belt void of the second strut. The apparatus further includes a thermal circuit (having a heat transfer fluid) extending from the cowling, through each of the struts, and into the lower unit.

A system for rotating inner and outer propeller shafts via a driveshaft. The system includes a stub shaft extending between forward and aft ends, the aft end having an engagement feature for engaging with the inner propeller shaft such that rotating the stub shaft rotates the inner propeller shaft. A reverse gear and a forward gear are each rotatably coupled to the stub shaft. The reverse gear and the forward gear mesh with the driveshaft and are engageable to become rotatably fixed to the stub shaft such that rotating the driveshaft rotates the stub shaft in reverse and forward directions, respectively. An outer driving gear is coupled to the inner propeller shaft to rotate therewith. An outer driven gear is coupled to the outer propeller shaft and a pinion rotatably coupling the outer driving gear to the outer driven gear such that rotation of the outer driving gear rotates the outer propeller shaft.

An outboard motor includes: a driveshaft housing configured to accommodate a driveshaft; and a gear case bulging laterally below the driveshaft housing and configured to accommodate a gear device, wherein an inside of the driveshaft housing communicates with an inside of the gear case, an introduction port for introducing lubricating oil into the gear case is opened on the driveshaft housing, and a confirmation port for causing the lubricating oil introduced into the gear case to flow out is opened on a front end side of the gear case.

A marine drive is for propelling a marine vessel. The marine drive has a drive assembly configured to support a propulsor for generating a thrust force in water, the drive assembly comprising a driveshaft housing and a gearcase suspended from the driveshaft housing, wherein the drive assembly is trimmable relative to the marine vessel about a trim joint, a steering actuator configured to steer the gearcase relative to the driveshaft housing, and a pump configured to pump a hydraulic fluid to and/or from the steering actuator via the trim joint.

An outboard motor includes a propeller shaft, a lower case, an upper case, and a splash guard. The lower case houses the propeller shaft. The upper case is located above the lower case. The splash guard includes an upper plate that projects forward from the upper case. The splash guard is separate from the upper case and is attached to the upper case.

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 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.

A marine propulsion device includes an engine, a driveshaft powered by the engine, a propulsor shaft coupled in torque-transmitting relationship with the driveshaft, and a propulsor coupled to the propulsor shaft and rotatable to produce a thrust. A housing supports the propulsor shaft therein. The housing has fore and aft skegs projecting from a bottom surface thereof.