An outboard-motor vibration-isolating cooler system apparatus providing a retrofit substitute for the midsection and the lower unit of a standard outboard motor, having a substitute closed-loop cooling system with an exterior heat exchanger, a substitute oil reservoir, a substitute exhaust system, and a substitute propulsion system with an isolating power-take-off shaft, allowing an existing standard outboard-motor powerhead to be used in conditions not conducive to standard open-loop water cooling, such as shallow-water, muddy-water, obstructed-water, seawater, or corrosive-water conditions.

An outboard motor includes a cooling water passage structure, in which a combustion chamber periphery water jacket through which the cooling water flows around the combustion chamber and an exhaust port periphery water jacket through which the cooling water flows around the exhaust port are formed in the cylinder head, a cylinder periphery water jacket through which the cooling water flows around the cylinder is formed in the cylinder block, and an exhaust passage periphery water jacket through which the cooling water flows around the exhaust passage is formed around the exhaust passage. The water jackets are connected such that the cooling water from the water passage will flow through the combustion chamber periphery water jacket, the exhaust port periphery water jacket, the cylinder periphery water jacket, and the exhaust passage periphery water jacket in order.

An outboard motor includes a catalyst housing passage disposed inside the V-shaped line, a cooling water passage including at least a portion disposed at a periphery of a catalyst and that guides cooling water that cools an exhaust passage and a vent hole disposed higher than the catalyst and that connects the interior of the cooling water passage to the exterior of the cooling water passage.

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 for a marine vessel application, and related methods of making and operating same, are disclosed herein. In at least one embodiment, the outboard motor includes a horizontal-crankshaft engine in an upper portion of the outboard motor, positioned substantially positioned above a trimming axis of the outboard motor. In at least another embodiment, first, second and third transmission devices are employed to transmit rotational power from the engine to one or more propellers at a lower portion of the outboard motor. In at least a further embodiment, the outboard 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 outboard motor includes numerous cooling, exhaust, and/or oil system components, as well as other transmission features.

An outboard motor includes an engine, a drive shaft, and a shift shaft disposed forward of the drive shaft. The shift shaft includes a first shift shaft that extends in an upward-downward direction, a second shift shaft disposed below the first shift shaft and spaced apart from and rearward of the first shift shaft, the second shift shaft extending in the upward-downward direction, and a shift force transmission to transmit, to the second shift shaft, a shift force applied to the first shift shaft.

An outboard-motor vibration-isolating cooler system method providing a retrofit substitute for the midsection and the lower unit of a standard outboard motor, having a substitute closed-loop cooling system with an exterior heat exchanger, a substitute oil reservoir, a substitute exhaust system, and a substitute propulsion system with an isolating power-take-off shaft, allowing an existing standard outboard-motor powerhead to be used in conditions not conducive to standard open-loop water cooling, such as shallow-water, muddy-water, obstructed-water, seawater, or corrosive-water conditions.

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.

The cooling device for a power source for a ship propulsion device that pumps up cooling water, from which foreign matters with sizes that cause clogging of a cooling water route have been removed, supplies the cooling water to a cooling water passage (30), and discharges the cooling water to outside after cooling a power source (10) includes: a cartridge-type filtration device (40, 73) that is provided at a midpoint of a first water passage (36, 71) in the cooling water route and incorporates a filter (45, 46) for filtrating foreign matters remaining in the cooling water; and a second water passage (38, 72) that is branched from the first water passage and adapted such that a valve member (53) is opened to cause the cooling water to flow in a case in which clogging occurs in the filter.

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.