Abstract: An outboard motor incorporates an engine. An exhaust conduit is disposed below the engine. The exhaust conduit forms a first exhaust passage to discharge exhaust gases from the engine. A plastic lubricant pan (e.g., oil pan) is disposed below the engine to accumulate lubricant that lubricates a portion of the engine. The lubricant pan at least in part surrounds the exhaust conduit. In some embodiments, a protective member is provided to protect the lubricant pan from flames that descend from the engine toward the exhaust conduit or heat of the exhaust gases. In other embodiments, a protective member includes an exhaust conduit that generally shields the lubricant pan such that the lubricant pan is not exposed to the flames or the exhaust gases.

Abstract: An outboard motor incorporates an engine. An exhaust conduit is disposed below the engine. The exhaust conduit forms a first exhaust passage to discharge exhaust gases from the engine. A plastic lubricant pan (e.g., oil pan) is disposed below the engine to accumulate lubricant that lubricates a portion of the engine. The lubricant pan at least in part surrounds the exhaust conduit. In some embodiments, a protective member is provided to protect the lubricant pan from flames that descend from the engine toward the exhaust conduit or heat of the exhaust gases. In other embodiments, a protective member includes an exhaust conduit that generally shields the lubricant pan such that the lubricant pan is not exposed to the flames or the exhaust gases.

Abstract: An outboard motor exhaust system that includes a simplified above-the-water exhaust gas discharge which is formed by an inverted U-shape tube that is detachably connected into the outer casing of the driveshaft housing so that the outer casing need not be formed with special passages for providing for exhaust gas flow.

Abstract: Several embodiments of outboard motors embodying four-cycle engines having an oil tank that is contained within the drive shaft housing and which is surrounded at least in part by a water cooling jacket for maintaining the oil at an acceptable temperature. The oil tank is formed with a cavity through which an exhaust pipe passes and the area between the exhaust pipe and the oil tank forms, in at least some embodiments, an expansion chamber for silencing the exhaust gases. At least in part of the exhaust pipe and/or expansion chamber is also cooled by a water cooling jacket.

Abstract: A cooling system for an outboard motor and specifically for the lubricating reservoir thereof. The lubricating reservoir depends into the drive shaft housing and is surrounded by an open trough-like water manifold to which cooling water is delivered from the engine. This manifold has lower restricted openings that direct the coolant to the outer peripheral wall of the oil pan of the lubricant reservoir. The water level is maintained by a weir-like structure and the water that overflows the weir is also directed toward the outer surface of the lubricant reservoir.

Abstract: An arrangement is provided for the lubricating, cooling and exhaust systems of a four-cycle outboard watercraft motor. Coolant is drawn from the body of water within which the watercraft is operated for circulation through the engine cooling system. Subsequently, the coolant is brought into proximity with an exhaust pipe extending downwardly from the engine within an encasing member. After passing downwardly along the exhaust pipe the coolant is finally directed towards an exhaust gas expansion chamber and a cooling water jacket provided around the expansion chamber. In order to prevent any of the cooling water from splashing back up against an oil reservoir, also located within the casing, a cover is provided across the tops of the expansion chamber and its accompanying cooling water jacket. Coolant water or air may fill the voids separating the various components contained within the encasing.

Abstract: A swivel bracket comprised of two pieces for a tiltable marine drive unit which enables the drive unit to be easily attached to, or detached from, the hull of a marine vessel. The first piece of the swivel bracket is pivotally secured to a clamp bracket which, in turn, is attached to the hull of a marine vessel. The second piece of the swivel bracket is connected at one end to the first piece of the swivel bracket by bolts and is rotatably secured at the other end to the drive unit for steering movement. The first and second pieces of the swivel bracket can be easily separated from each other.

Abstract: A tilt handle which is secured to the power head of an outboard drive unit on a marine vessel for moving the drive unit through a small tilt angle from a tilted-down position in which the drive unit propeller is below the surface of the water to a tilted-up position in which the propeller is out of the water. The drive unit includes an elongated swivel bracket which places the power head a substantial distance from the vessel when running. On such a drive unit, the tilt handle assists in the tilting up operation and permits the power head to be positioned near the vessel for easy operation and maintenance by the driver of the vessel.

Abstract: A tilting device for a tiltable outboard drive unit on a marine vessel which prevents the drive unit, when in the tilted-down position, from freely moving toward the tilted-up position during normal operation. The tilting device includes a tilt cylinder device having a bypass valve, and is arranged so that the bypass valve of the tilt cylinder device is automatically closed when the drive unit is in the tilted-up position. Thereafter, when the drive unit is moved to the tilted-down position the bypass valve remains closed, thereby preventing the drive unit from freely moving toward the tilted-up position during normal operation.

Abstract: A tilt cylinder device for a tiltable outboard drive unit on a marine vessel positioned so that the stress acting on the tilt cylinder device and its associated parts is decreased when the drive unit collides with an underwater obstacle. The tilt cylinder device is also positioned so that the stop pin, used for setting the downward tilt position of the drive unit, is not obstructive to the removal of the tilt cylinder device.

Abstract: An improved steering device for a marine propulsion unit that incorporates a steering bracket that is clamped to the transom of the associated watercraft in proximity to the tilt axis of the outboard drive. A steering rod is reciprocally supported in a bore in the steering bracket and is connected at one end to a push pull cable and at the other end to the steering arm of the outboard drive for effecting its steering.

Abstract: Several embodiments of outboard motors embodying four-cycle engines and improved lubricating systems therefor. In all of the embodiments, an oil reservoir is provided in the drive shaft housing and a combined screen and drain plug assembly filters the oil flowing from the oil reservoir to the engine lubricating system and for facilitating servicing of the screen by removal of the drain plug. In one embodiment, the oil reservoir is formed integrally with the drive shaft housing. A pressure relief valve depends into the oil reservoir and is carried by a plate that connects the engine to the drive shaft housing for facilitating servicing and reducing the likelihood of leakage back of oil to the engine when the outboard motor is tilted up. An improved relief valve screen assembly is also illustrated in one embodiment where in the screen may be bypassed if it becomes clogged.

Abstract: Several embodiments of steering devices for outboard motors that are operative to hold the outboard motor in a steered position but which will release upon emergency application due to fracturing of a frangible member. In each embodiment, the steering device comprises a pin that is movable into and out of engagement with an opening formed in the other of the members. In some of the embodiments, the member in which the opening is formed is frangible and, in another, the pin is frangible.

Abstract: An outboard motor embodying an improved steering mechanism that is operative to retain the motor in a preset steered position and which may be easily and automatically disengaged by the operator to permit steering under emergency conditions. In addition, the means for retaining the motor in its steered condition is operable from a remote position at the end of the tiller in proximity to the operator so that he need not remove a hand from the tiller to either engage or release the mechanisms. Furthermore, other controls for the engine are disposed at the end of the tiller in proximity to the steering control.

Abstract: Several embodiments of outboards motors embodying four-cycle engines and improved lubricating systems therefor. In all of the embodiments, an oil reservoir is provided in the drive shaft housing and a combined screen and drain plug assembly filters the oil flowing from the oil reservoir to the engine lubricating system and for facilitating servicing of the screen by removal of the drain plug. In one embodiment, the oil reservoir is formed integrally with the drive shaft housing. A pressure relief valve depends in to the oil reservoir and is carried by a plate that connects the engine to the drive shaft housing for facilitating servicing and reducing the likelihood of leakage back of oil to the engine when the outboard motor is tilted up. An improved relief valve screen assembly is also illustrated in one embodiment where in the screen may be bypassed if it becomes clogged.

Abstract: Two embodiments of control device for outboard motors wherein the engine throttle control, transmission control and kill switch are all supported by the steering handle and are operative independently of each other. In one embodiment, the transmission control is pivotal about an axis offset to an axis of rotation of the throttle control. In the other embodiment, the transmission control is reciprocal along a line parallel to the axis of rotation of the throttle control.

Abstract: An improved propeller blade configuration that permits a relatively strong configuration without reducing the cavitation thickness or efficiency of the blade. This is achieved by providing a planar section on the front face of the blade that merges into a recessed cup shaped portion and by having the rearwardmost axial portion of the rear face lie in an axial direction contiguous to the point of merger.