Abstract: The vibro-acoustic energy produced by an engine is reduced by shrouding the powerhead with a blanket of material that both damps vibrations and absorbs acoustic wave energy. This vibro-acoustic treatment is applied on the inner surface or surfaces of a motor housing of a propulsion system. The housing is treated by adhering a sheet of acoustic barrier material to the housing inner surface. The acoustic barrier material is designed to block transmission therethrough of a substantial portion of impinging acoustic wave energy in a range from at least 1,000 to 3,000 hertz. The layer of adhesive material has a thickness such that impinging acoustic wave energy in a range of 1,000 to 3,000 hertz is efficiently converted into heat energy. An open-cell foam core laminated to the sheet of acoustic barrier material absorbs the trapped, blocked, acoustic wave energy. The open-cell foam core has an average pore size that is optimized to absorb acoustic wave energy in a range of 1,000 to 3,000 hertz.

Abstract: A fuel injected, internal combustion engine that is protected from detrimental ignition due to pocket sparking. The engine includes one or more cylinders into which fuel is injected by an injector. A spark plug is used to ignite the fuel-air mixture within the cylinder. The spark plug is designed with a base and a shell extending from the base to define a hollow interior. A central electrode is disposed in an insulative core and extends through the hollow interior of the shell. The shell is connected to a secondary electrode. A gap is formed between the electrodes for promulgation of a spark to ignite the fuel-air mixture. The detrimental effects of pocket sparking are eliminated by placing a closure member between a terminal end of the shell and the nose of the insulative core. This closure member may be in the form of a lip that extends from the shell into proximity with the nose of the insulative core.

Abstract: State-of-the-art fuel injectors can be defined by a third-order polynomial to define their performance curve and to optimize performance of the fuel injected engine. Such systems are preprogrammed to use a set of fixed coefficients when replacing fuel injectors. Therefore, these replacement fuel injectors must be manufactured with very precise tolerances so as to operate efficiently with these fixed coefficients. The present invention includes a method and apparatus that allows the use of production fuel injectors that are more economical since they can be manufactured with wider tolerances. The production fuel injectors are supplied with a computer program and a data file having a set of replacement coefficients that are determined especially for that particular fuel injector. The approach allows the restoration of the existing coefficients if the replacement fuel injector does not solve the service problem experienced by the user of the fuel injected engine.

Abstract: A marine propulsion device (12) including a sleeve (32) formed around an exhaust conduit (26) to form an air cooling passage (34) there between. Cooling air (38) is moved through the cooling passage (34) by an active fan (42) and/or a passive venturi (56). Cooling air (38) is drawn from within an engine compartment (24) for a predetermined time before and after the engine (16) is operated. A water-cooled discharge support (70) is located above the waterline (28), thereby preventing the intermixing of exhaust gasses (36) with the environmental water (27).

Abstract: A propeller assembly that includes, in an exemplary embodiment, a spring for securing a propeller to a propeller shaft is described. In the exemplary embodiment, the propeller assembly includes a thrust bearing which tightly fits to an inclined surface of the propeller shaft. The thrust bearing includes a hub mating surface which forms a tight fit with one end of a hub of the propeller. The propeller hub has a cylindrical shape, and a plurality of blades extend from an outer surface of the hub. A bore extends through the propeller hub, and the spring fits securely within the hub bore. The spring is located within the propeller hub bore and is secured, e.g., welded, at one end to an interior surface of the hub. The assembly further includes a washer and a nut which engages to a threaded end of the propeller shaft.

Abstract: A shift control method and assembly for a marine drive having a transmission with a clutch member movable between a neutral position and a drive position are provided. The assembly includes a first lever responsive to a remotely actuated link and a second lever is connected to drive the clutch member. The assembly further includes a clutch subassembly interconnected between the first and second levers. The clutch subassembly is configured to selectively pivot the second lever to effect movement of the clutch member, and to permit over-travel of the link connected to the first lever without pivoting the second lever upon engagement of the clutch member in the drive position. The clutch member may be returned to neutral without first having to recover any initial overstroke, that is, when it is desired to return the transmission to neutral, rotation of the first lever immediately rotates the second lever, such that the transmission returns to neutral before the first lever reaches neutral.

Abstract: An inboard/outboard powered watercraft (10) incorporating a transmission (30, 80) in its vertical drive unit (24) for providing two forward speeds plus reverse. The transmission is packaged to fit within the vertical drive unit (24) by incorporating a bevel gear apparatus (44, 120). In one embodiment, the transmission (30) also includes a planetary gear apparatus (46) together with two hydraulic clutches (70, 72) and a ring gear brake (56). In a second embodiment, three hydraulic clutches (98, 100, 114) are utilized with bevel gears (94,96,106,110,112) alone to provide the two forward and reverse speeds.

Abstract: A propulsion system for a boat has a powerhead or a motor with an exhaust port for exhaust gases. The exhaust gases are exhausted through the propeller hub via an exhaust housing. The exhaust housing is a walled enclosure having an inlet, an internal volume in flow communication with the inlet, and an outlet in flow communication with the internal volume. The exhaust housing further includes hollow structures for dividing a portion of the internal volume into a plurality of flow channels which extend in side-by-side relationship. The transverse dimensions of each flow channel is substantially less than the transverse dimensions of the walled enclosure. The result is that standing waves are shifted to a higher frequency range. The hollow dividing structures have internal volumes which communicate with space external to the exhaust housing via openings in the walled enclosure, which allow the admission of a cooling medium.

Abstract: A transom seal assembly for sealing an opening in a boat transom is provided. A propulsion system has a part thereof extending through the transom opening. The seal assembly comprises an inflatable seal between respective peripheries of the part and the transom opening to provide water-tight sealing relative to the interior of the boat even in the presence of a seal puncture condition.

Abstract: A fuel injector nozzle includes a nozzle body and a poppet disposed in the body for reciprocating movement. The body has an internal bore surrounding the poppet. The internal bore tapers in a constant angle of taper from a front seating region to a fuel reservoir region. The poppet has a corresponding surface which diverges slightly from the bore. The surfaces of the bore and poppet form flow control surfaces which terminate in a sharp-edged orifice at the front face of the nozzle. When the poppet is displaced to an open or flow position, fuel is accelerated to the orifice and atomized into a combustion chamber. The poppet surface being formed so as to properly direct fuel after the poppet surface is machined.

Abstract: A technique is provided for steering and navigating a watercraft. The technique provides for dual electric motor propulsion units aft of a transverse centerline of the watercraft. A forward thruster system is provided forward of the transverse centerline. The rear drive units provide components of thrust for navigating the craft through straight-ahead settings and turning settings. The forward thruster system provides additional thrust components for moving the watercraft in a “sliding” direction, and for providing additional turning thrust. The system is particularly well suited to slow-speed navigation, such as for recreational fishing, as well as for close quarters navigation and docking.

Abstract: A system and method is provided for calibrating a position sensor having a variable output corresponding to the variable position of a movable member. The system and method establishes for the position sensor a first output corresponding to a first given position of the movable member. The system and method stores the first output from a first operating session in memory to use in establishing the first output for a second operating session. The system and method may also use a biasing factor in establishing the first output for a second operating session. The system and method may also establish a second output corresponding to a second given position of the movable member as a function of a second output from a previous operating session or as a function of a biasing factor. The system and method may be used to control an internal combustion engine.

Abstract: The present invention provides a header for rigidly engaging an upper edge of a boat windshield and supporting a boat canopy. The header comprises an elongated member having a generally uniform transverse cross-section. The cross-section is defined by an upper rail having a convexly curved top surface and a bottom defining first and second respective sides. First and second arms protrude downwardly from the first and second sides of the upper rail. A windshield-engaging channel for receiving the boat windshield is formed between the first and second arms. A first groove is formed within the upper rail and extends inwardly from the first side of the upper rail. To reduce wear and tear on a boat canopy attached to the header, the curvature of the convexly curved top surface increases from the first side to the second side of the upper rail to maximize the load-bearing contact area between the canopy and the header.

Abstract: A gear shift mechanism for a marine propulsion system includes a reversible DC electric motor, a sliding clevis, and a shift rod for actuating a gearset within a gearcase between forward, reverse, and neutral positions. The mechanism is housed in a watertight gear shift cover that is attached to a trunnion that, in turn, attaches to a top surface of the gearcase. Electronic, logic driven controls reverse the polarity of the motor to manipulate the shift rod via the sliding clevis to shift the gearcase into a selected operating position.

Abstract: A flywheel (20) having a molded cage (30) formed around a plurality of magnets (34) attached to the flywheel (20). The cage (30) extends into one or more grooves (40,42) formed in the flywheel (20) to resist the shrinkage of the cage 30 inside diameter as it cools following an injection molding process. The gap (44) between the cage (30) and magnets (34) and an adjacent stator (32) is precisely controlled and minimized. Shutoff surfaces (36,38,46) formed on the flywheel (20) function as a portion of the die for injection molding of the cage (30).

Abstract: A hull is described having bow, stern, port and starboard sides. At least one chine extends longitudinally from a first point near the bow to a second point near the stern of the hull. At least one wedge section is disposed along the at least one chine and is adapted to minimize porpoising of the hull when in operation. A boat having such a hull is also described.

Abstract: A fluid level sensor for a fluid tank of a marine vessel is provided. The sensor includes a sensor mount and further includes a circuit housing that is pivotally connected to the mount to pivot about a predetermined pivot axis. A float assembly is configured to supply an actuating angle substantially impervious to fluid tank tilt and/or fluid splash at least along an axis generally perpendicular to the pivot axis. A circuit in the circuit housing is responsive to the actuating angle from the float assembly to provide an output signal indicative of the fluid level in the tank.