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 propelling system of a powered ship includes a support, outboard motor, guide component and water inlet unit. The support is disposed at a stern. The outboard motor is mounted on the support. A blade wheel is disposed at the bottom of the outboard motor. The axis of the blade wheel is higher than a hull. The guide component has a guide ring for concealing the blade wheel and a nozzle connected to the guide ring. The water inlet unit is disposed at the stern and below the support. The water inlet unit has a water inlet hole and water outlet hole. A water inlet channel is formed between the water inlet hole and water outlet hole. The support enables the outboard motor to be mounted higher. The guide component and water inlet channel enable water to be conveyed at low pressure and ejected at high flow rate.

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.

A marine outboard motor for a marine vessel is provided. The marine outboard motor includes an internal combustion engine, a drive shaft configured to transmit a drive force from the internal combustion engine, a propeller shaft, and a drive transmission configured to transmit the drive force from the drive shaft to the propeller shaft. The motor also includes a lubrication system configured to convey lubricant along a lubricant flow path to lubricate one or both of the drive transmission and the drive shaft, and a lubricant filter provided along the lubricant flow path and configured to remove solid contaminants from the lubricant as it flows along the lubricant flow path. The lubricant filter is configured to be driven by the drive shaft.

An intake manifold is connected to a cylinder head, and extends backward therefrom. An injector is attached to either the cylinder head or the intake manifold. At least one of the cylinder head and the intake manifold includes a curve pipe portion shaped to curve backward from a lateral surface of the cylinder head. An injector is attached to the cylinder head at either an outer lateral surface of the curve pipe portion in a right-and-left direction of an outboard motor or a position located forward of the curve pipe potion.

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.

An outboard motor includes a shaft including a second spline that upwardly extends from a housing. The second spline is meshed with a first spline disposed inside either an engine cowl or an upper housing. The second spline includes a distal end and a body. The distal end is provided on an upper end of the shaft. The body is provided below the distal end. In the second spline, a groove width in the circumferential direction at the distal end is larger than a groove width in the circumferential direction at the body.

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 has a top cowl and a service lid on the top cowl is movable into and between a closed position enclosing the powerhead compartment and an open position providing manual access to the powerhead compartment from above the outboard motor. An engine is in the powerhead compartment, wherein a peripheral gap is defined between the top cowl and the engine. A serviceable engine oil device is in the peripheral gap and is manually accessible from above the outboard motor when the service lid is in the open position. A serviceable transmission fluid device is in the peripheral gap and is manually accessible from above the outboard motor when the service lid is in the open position. A serviceable gearcase fluid device is in the peripheral gap and is manually accessible from above the outboard motor when the service lid is in the open position.

A stern drive is for propelling a marine vessel in a body of water. The stern drive has a powerhead, a mounting assembly configured to affix the powerhead to the transom, inside the marine vessel, and a drive assembly coupled to the mounting assembly, the drive assembly being trimmable up and down relative to the mounting assembly, the drive assembly comprising a driveshaft and an output shaft which extends transversely to the driveshaft. The drive assembly has a driveshaft housing for the driveshaft and a gearcase housing for the output shaft, wherein the gearcase housing is steerable relative to the driveshaft housing. A universal joint couples the powerhead to the driveshaft so that operation of the powerhead causes rotation of the driveshaft, which in turn causes rotation of the output shaft.