Abstract: Some embodiments relate to a catalytic assembly for an engine. The catalytic assembly includes a cooling housing that receives a coolant (e.g., seawater). A catalyst housing is disposed within the cooling housing such that the coolant flows between the catalyst housing and the cooling housing. A catalyst substrate is positioned within the catalyst housing such that exhaust gases from the engine flows through the catalyst substrate. The catalyst substrate serves to covert harmful emissions found in the exhaust gases to less harmful emissions. The catalyst housing includes a first fitting and cooling housing includes a second fitting that mates with the first fitting to prevent rotation of the catalyst housing relative to the cooling housing.

Abstract: Some embodiments relate to a catalytic assembly for an engine. The catalytic assembly includes a cooling housing that receives a coolant (e.g., seawater). A catalyst housing is disposed within the cooling housing such that the coolant flows between the catalyst housing and the cooling housing. A catalyst substrate is positioned within the catalyst housing such that exhaust gases from the engine flows through the catalyst substrate. The catalyst substrate serves to covert harmful emissions found in the exhaust gases to less harmful emissions. The catalyst housing includes a first fitting and cooling housing includes a second fitting that mates with the first fitting to prevent rotation of the catalyst housing relative to the cooling housing.

Abstract: An engine structure is provided with a bedplate and an oil pan. The bedplate is configured to have an integrally formed balance shaft bearing support. A bearing cap is either a separate component or a component that is formed as an integral part of the oil pan. The bearing cap and the balance shaft bearing support structures are attachable to each other to capture the bearing portions of the balance shafts therebetween.

Abstract: A marine transmission provides a cylindrical spool valve that is disposed within the gear case of the transmission and has a movable portion that is axially movable in a vertical direction to select forward, neutral, and reverse gear positions of the transmission. A piston assembly provides a primary piston and two auxiliary pistons which cooperate with each other to provide appropriate hydraulic forces which move a dog clutch into engagement with forward or reverse gears or toward a location in non-engagement with neither the forward nor reverse gears. The spool valve is generally cylindrical and disposed within a narrow column portion of the gear case of a marine propulsion system.

Abstract: A shock absorber for a marine propulsion device is configured to provide an adapter, coupler and resilient device which can be assembled into a unit, or module, that can be inserted into a propeller. The resilient device includes two helical springs that urge the coupler into a central position with respect to the adapter and resist relative axial motion between the adapter and coupler. The shock absorber is intended to absorb the forces which occur during a shift from neutral to forward gear of the marine propulsion device.

Abstract: A casing is provided to be disposed around at least a portion of a counterweight of a balance shaft in order to define a circumferential surface surrounding the counterweight which has a generally constant radius relative to the axis of rotation. The function of the casing is to reduce or eliminate aeration of oil in which the balance shaft is disposed.

Abstract: An actuator for a marine transmission uses four cavities of preselected size in order to provide four potential forces resulting from pressurized hydraulic fluid within those cavities. The effective areas of surfaces acted upon by the hydraulic pressure are selected in order to provide increased force to move the actuator toward a neutral position from either a forward or reverse gear position. Also, the relative magnitudes of these effective areas are also selected to provide a quicker movement into gear than out of gear, given a similar differential magnitude of pressures within the cavities.

Abstract: A marine propulsion support system incorporates a vibration isolation structure which comprises a plurality of elastomeric support components, or mounts. The vibration isolation structure is disposed between a marine vessel and a propulsion drive mounting transom to which a marine propulsion component, such as an outboard motor, can be attached. Support of the propulsion drive mounting transom by the marine vessel extends through the vibration isolation structure so that elastomeric portions of the elastomeric support components can damp any vibration emanating from a marine propulsion device, such as an outboard motor, and a deck of a pontoon boat or other marine vessel.

Abstract: A container, or pod, is provided for a pontoon boat in which an engine is disposed within the container and the container is supported below the deck surface of the pontoon boat. The container is shaped to prevent its passing completely downwardly through an opening in the deck surface when it is assembled from a position above the deck. A marine propulsion device is connected to the engine which is located within the pod, or container, and extends from the container when the container and the marine propulsion device are supported below the deck of the pontoon boat.

Abstract: A marine propulsion system is configured to be preassembled prior to the attachment of a marine engine to the marine vessel. In other words, the marine engine is attached to a transom plate, a gimbal ring, and a bell housing prior to insertion of the engine into the marine vessel. The subassembly is then moved rearwardly to cause the bell housing, gimbal ring, and portion of the transom, bracket to pass through a preformed opening in the transom. Subsequently, a transom ring is attached to the transom bracket to affix the subassembly to the transom. Then a marine drive unit is attached to the bell housing.

Abstract: A lubrication system for an in-line engine which has a piston symmetry plane that is tilted relative to a vertical plane is provided with an oil pan and windage tray that facilitates the transfer of oil from a rotating crankshaft to the oil pan without excessive aeration. In addition, it facilitates the removal of entrained air from liquid oil as it passes from the crankshaft to a pool of oil collected in an oil pan. A windage tray is provided with a louver structure and a louver opening structure that assists this passage of oil droplets without undue aeration being caused.

Abstract: An actuator of a marine propulsion transmission is attached to a movable clutch member through the use of a coupler which comprises a generally spherical member formed as a portion of the actuator and a chuck device formed as part of the clutch member. The generally spherical member, or alternatively shaped component, is received by the chuck device and retained therein. The components are configured to allow relative rotation between the actuator and the clutch member while causing them to move axially in synchrony with each other.

Abstract: A support system for a marine engine provides a plurality of mounts that have primary axes that are aligned in parallel relation with a piston symmetry plane of the engine. These primary axes of the mounts are also aligned with the central axes of the cylinders of the engine. This arrangement improves the damping function of the mounts and more effectively isolates engine vibrations from the marine vessel.

Abstract: A shift assist mechanism is provided with a position identification device that incorporates one or more probes in association with one or more depressions that identify alignment between various positions on the piston and cylinder of the shift assist mechanism. Electrical conductivity or non-conductivity of three electrical conductors identifies the relative axial positions of these components. In addition, the electrical conductors of the system allow the detection of water within the lubricating oil of the transmission.

Abstract: A pontoon boat is provided with a jet drive propulsion system in which an impeller is driven by an engine. The jet drive propulsion device is dirigible as a result of the fact that a nozzle of the device is rotatable about a generally vertical steering axis. The jet drive device can be supported below a deck of a pontoon boat and located between two flotation tubes of the pontoon boat. Alternative locations can also be used, such as within the structure of the flotation tubes themselves.

Abstract: A self-contained marine propulsion device is disposed within a container, or pod, that is removably attachable to an undersurface of a deck of a pontoon boat. An engine is contained within the container and connected in torque transmitting relation with the marine propulsion device which can be a sterndrive device or a jet drive device. The marine propulsion system is dirigible, with a portion that is rotatable about a generally vertical steering axis and is supported by the container which is attached to the deck of the pontoon boat.

Abstract: A marine propulsion system is configured to be assembled, as one unitary structure, into a marine vessel. A transom attachment member is provided and is attachable to both an engine and a drive unit to form a single marine propulsion system structure which can be lowered into an opening formed in a transom of a marine vessel.

Abstract: The heat exchanger for a marine propulsion system is located within available space in front of the transom of a marine vessel and attached to the transom. The housing of the heat exchanger can be attached to a drive unit support structure and spaced apart from an engine of the marine propulsion system. Within the heat exchanger, engine coolant is circulated through a first coolant path and water from the body of water is circulated through a second coolant path.

Abstract: A marine propulsion system is provided with inner and outer bellows, or tubes, which are rigidly attached to both the transom bracket and the driveshaft housing of the sterndrive system. Neither the inner nor outer tubes rotate with the driveshaft. Both the inner and outer tubes, or bellows, allow the driveshaft to rotate relative to the transom bracket about either a steering axis or trim axis. An exhaust passage is defined between the outer surface of the inner tube and the inner surface of the outer tube. This structure provides an efficient positioning of the two tubes while protecting the universal joint within the inner tube from the exhaust gases. Encompassing the inner tube within the outer tube increases the possible area that can be used for the exhaust passage in comparison to providing two individual tubes, one for the universal joint and the other as an exhaust passage.