Abstract: An outboard motor includes a cowling substantially enclosing an engine therein. A tilt and trim mechanism includes a manually-actuable tilt switch for controlling tilt and trim of the motor. Both the port and starboard sidewalls of the cowling have apertures formed therethrough. The apertures are sized and configured to accomodate a tilt switch. In one embodiment, a tilt switch is arranged in one aperture and a plug is arranged in the other aperture. In another embodiment, tilt switches are arranged in both apertures.

Abstract: A component mounting arrangement for an engine includes an improved construction that can allow components such as a wire harness and/or fluid conduits to be neatly arranged around the engine. The engine includes a valve actuation mechanism and a drive mechanism through which a crankshaft drives the valve actuation mechanism. The drive mechanism is disposed generally above a cylinder block and a cylinder head assembly. At least one guide member is arranged to guide the wire harness and/or the fluid conduit across the engine. The guide member traverses above the drive mechanism.

Abstract: A valve actuating system for actuating at least one valve of an engine includes an improved mechanism for varying the timing and/or lift of the valve. The mechanism uses two adjacent rockers that cooperate with two adjacent cams of a camshaft. In one operating condition, movement of a first rocker is transmitted to the valve through the second rocker and in another operating condition only the movement of the second rocker is transmitted to the valve. The rockers preferably cooperate with cams having different lifts. The lift of the cam driving the first rocker preferably is greater than the lift of the cam driving the second rocker.

Abstract: A marine drive transmission includes an improved shock-absorbing coupling mechanism. Engine power is transmitted to a propulsion device through a drive shaft and driven shaft. The drive shaft is coupled to the driven shaft by a coupling arrangement which has a first coupling mechanism and a second coupling mechanism. The second coupling mechanism is spaced apart from the first coupling mechanism in a direction along a common axis of the shafts. The shafts are coupled with each other selectively by one of the first and second coupling mechanisms. The first coupling mechanism desirably includes an elastic member or a viscosity coupling. The second coupling mechanism desirably includes a toothed mechanism, which functions as the primary coupling between the drive and driven shafts (i.e., overrides the first coupling) once a predetermines load has been applied to the drive shaft.

Abstract: An outboard motor includes an internal combustion engine having an induction system formed of a pair of vertically extending plenum chambers which communicate with the combustion chambers formed in the engine via a plurality of intake runners. A common throttle device is located upstream from the plenum chambers and communicates with the plenum chambers via an induction passage having an branch portion. The throttle device is arranged at least partially below an upper surface of the crankcase of the engine. Thus, the overall height of the engine is reduced, thereby reducing the overall height of an outer cowling member provided over the engine.

Abstract: A tilt and trim arrangement for marine propulsion includes an improved construction. A swivel bracket, which carries a drive unit for pivotal movement about a steering axis includes a pair of ribs spaced apart transversely from each other. A clamping bracket is affixed to an associated watercraft and supports the swivel bracket for pivotal movement about a tilt axis. A hydraulic tilt device is provided for tilting the swivel bracket. The tilt device includes a cylinder housing, a piston slidably supported within the housing and a piston rod affixed to the piston. The cylinder housing has an upper section with a diameter that is smaller than a lower section, and the piston rod extends outwardly from the upper section. The piston rod is pivotally affixed to the ribs. The upper section of the cylinder housing is generally positioned between the ribs at least when the piston rod is fully retracted within the cylinder housing.

Abstract: A marine outboard drive, such as an outboard motor, includes both a splash plate and an anti-splash device. The anti-splash device includes a second splash plate that is provided on a lower mount, which couples together a swivel bracket and a drive housing. The second splash plate extends generally forwardly of the swivel bracket just under a lower portion of a clamp bracket that supports the swivel bracket. The anti-splash device preferably also includes a guide that is provided above the conventional splash plate for directing splashed water rearwardly so that the water is guided away from a mount cover that covers the lower mount. These features of the anti-splash device are particularly useful when the outboard drive is used with a pontoon boat.

Abstract: A component mounting arrangement for an engine includes an improved construction that can allow components such as a wire harness and/or fluid conduits to be neatly arranged around the engine. The engine includes a valve actuation mechanism and a drive mechanism through which a crankshaft drives the valve actuation mechanism. The drive mechanism is disposed generally above a cylinder block and a cylinder head assembly. At least one guide member is arranged to guide the wire harness and/or the fluid conduit across the engine. The guide member traverses above the drive mechanism.

Abstract: A marine drive includes an improved transmission and shifting mechanism to facilitate a smoother transition when shifting into a reverse drive condition. The transmission includes a positive clutch and a friction-type sub-clutch. The shifting mechanism desirably includes a shift cam with first and second cam surfaces. The first cam surface effects actuation of the positive clutch and the second cam surface effects actuation of the friction sub-clutch. The first and second cam surfaces are configured so that the shifting mechanism causes the friction sub-clutch to engage before the positive clutch engages. As a result, the instantaneous loading on an engine of the marine drive when shifting the transmission into reverse is reduced.

Abstract: An improved thrust taking arrangement for an outboard drive includes an anti-friction member that transfers the thrust between the trim adjusting thrust member and the outboard drive. The anti-friction member is attached on the thrust taking member and is made of a material having a smaller coefficient of friction than both of the thrust member and the thrust taking member for reducing friction upon reciprocation of the thrust member.

Abstract: A shifting mechanism for an outboard drive of a watercraft provides reduced coupling shock when the forward gears are engaged by a dual clutch assembly, as well as provides for consistent and quick engagement of the clutch assembly with the gear. The shifting mechanism involves a first gear and a corresponding first clutch, and a second gear and a corresponding second clutch. A plunger carries the first and second clutches which are arranged on the plunger at unequal distances from their respective gears. This nonuniform spacial relationship between the clutches and gears causes one clutch to engage its corresponding gear before the other clutch engages its corresponding gear. The staggered engagement decreases shock on the transmission and permits quicker engagement between the clutches and gears.

Abstract: An exhaust system for a marine propulsion outboard drive wherein the exhaust gases are normally discharged to the atmosphere at a point below the level of the body of water in which the watercraft is operating. A catalyst bed is provided in the exhaust system and the catalyst bed is protected from damage by precluding the flow of water in the exhaust conduit to the catalyst bed in response to certain conditions. These conditions may be either rapid deceleration of the engine or watercraft, stopping of the engine, or any of a combination of sensed factors. The water is precluded either by purging it through air pressure or from generating heat in the exhaust conduit, by providing a heat source in the exhaust conduit that will cause water to vaporize and increase the pressure or by a valve in the exhaust conduit positioned below the catalytic bed. The preclusion of water is initiated for only a predetermined time or until the sensed condition no longer is existent.

Abstract: A shifting mechanism for an outboard drive of a watercraft provides reduced coupling shock when the forward gears are engaged by a dual clutch assembly, as well as provides for consistent and quick engagement of the clutch assembly with the gear. The shifting mechanism involves a first gear and a corresponding first clutch, and a second gear and a corresponding second clutch. A plunger carries the first and second clutches which are arranged on the plunger at unequal distances from their respective gears. This nonuniform spacial relationship between the clutches and gears causes one clutch to engage its corresponding gear before the other clutch engages its corresponding gear. The staggered engagement decreases shock on the transmission and permits quicker engagement between the clutches and gears.

Abstract: A transmission for a counter-rotating propeller system of a watercraft outboard drive has a compact arrangement so as to occupy less space in the lower unit of the outboard drive and thus provide increased flow area for exhaust discharge. The transmission includes a pair of counter-rotating gears. A front clutch selectively drives a main propulsion shaft by engaging either of the gears. A rear clutch drives an outer propulsion shaft by engaging the rear gear. The rear gear includes a bearing hub that receives the rear clutch which moves within the bearing hub between an engagement position and a non-engagement position. The overlapping arrangement between the rear gear and the rear clutch reduces the axial length of the transmission to present a compact arrangement of these components.

Abstract: A hydraulic assisted outboard drive arrangement wherein the hydraulic assist is controlled by an electric motor driven fluid pump. To assure the availability of hydraulic fluid immediately upon demand, the electric motor is continuously driven at a low speed and is switched it a higher speed in the event of operator demand for power assist.

Abstract: An improved outboard motor construction having a power head which has a water tight lower portion which is submerged when the associated watercraft is not in a planing condition so as to provide a buoyant assist for the watercraft to reach the planing condition without any attended hydrodynamic drag when planing.

Abstract: A shifting mechanism for an outboard drive of a watercraft provides reduced coupling shock when the forward gears are engaged by a dual clutch assembly, as well as provides for consistent and quick engagement of the clutch assembly with the gear. The shifting mechanism involves a first gear and a corresponding first clutch, and a second gear and a corresponding second clutch. A plunger carries the first and second clutches which are arranged on the plunger at unequal distances from their respective gears. This nonuniform spacial relationship between the clutches and gears causes one clutch to engage its corresponding gear before the other clutch engages its corresponding gear. The staggered engagement decreases shock on the transmission and permits quicker engagement between the clutches and gears.

Abstract: A shifting mechanism for an outboard drive of a watercraft provides a simple and compact transmission, as well as streamlines a lower unit of the outboard drive to reduce fluidic drag. The shifting mechanism is located on a drive train generally aligned along a vertical axis and above a propulsion shaft of the lower unit. The drive train includes a rotatable input shaft which is driven by a motor. The transmission of the shifting mechanism, which is located above a cavitation plate of the housing of the outboard drive, selectively couples the input shaft and a drive shaft. The drive shaft in turn is coupled to the propulsion shaft. The transmission includes a clutch which is slidably connected to the drive shaft to move along the vertical axis into and out of direct engagement with the input shaft.

Abstract: An improved steering mechanism for a marine outboard drive wherein the steering rod connected to the outboard drive end of the wire actuator steering cable is slidably mounted in a guide tube that is formed integrally with a hydraulic assist cylinder and which are affixed to the transom independently of the tilt pin and forwardly of it. This permits the steering mechanism to be assembled as a unit separately from the outboard drive and attached to the transom separately from it.

Abstract: A hydraulic assisted steering mechanism for marine propulsion drive wherein the hydraulic assist is operated by a control valve having its valve element actuated by a wire actuator that is operated by the steering mechanism. The actuating element that interconnects the wire actuator to the control valve element is supported for movement in a variety of embodiments so as to confine the movement in same direction as the valve element.