Abstract: A throttle plate control system mounts a rotational position sensor directly to a throttle body structure to take advantage of vibration isolation provided for the throttle body structure. The configuration is compact and connects the throttle plate of the throttle body structure in force transmitting relation with a rotational position sensor by using a cam structure. A cam member is coupled to a movable portion of a rotational position sensor and a cam follower is rigidly attached to the throttle plate shaft within the throttle body structure. By shaping the cam surface of the cam member, a nonlinear relationship can be specifically predetermined in order to maximize the operation of a throttle control system.

Abstract: A sound attenuation system for a compressor of a direct fuel injected engine of an outboard motor comprises a discharge sound attenuator connected in fluid communication with an air distribution manifold outlet and a suction sound attenuator connected in fluid communication with the suction port of a compressor. In a typical application of the present invention, the air distribution manifold is connected in fluid communication with a discharge port of the compressor. Both the discharge sound attenuator and the suction sound attenuator can further include filter media disposed within their internal cavities.

Abstract: A torsional damper is provided for an outboard motor and disposed between a flywheel and the engine of the outboard motor. The torsional damper is also shaped to be disposed within a cavity of the flywheel formed by a plate portion and a skirt portion of the flywheel. The torsional damper comprises an inner member that is attached to the flywheel, an outer wheel that operates as a spring mass, and a resilient central member that is made of an elastomeric material and disposed between the inner and outer members.

Abstract: An oil lubrication system for a marine outboard motor including an internal combustion engine. The oil lubrication system includes a series of oil passageways within the cylinder block of the internal combustion engine. The oil passageways are configured such that each cylinder in the internal combustion engine is supplied by its own oil passageway. Each of the oil passageways terminate in an outlet opening. The outlet opening is positioned within the cylinder block such that oil exiting the outlet opening is directed by the force of gravity into contact with a moving component of the internal combustion engine. As the internal components of the internal combustion engine move, oil contacting the components is physically distributed into contact with the bearings.

Abstract: A lubrication system for an internal combustion engine provides drain openings at locations within individual crankcase portions where residual oil collects during normal operation. The drain openings are connected to orifices formed through cylinder walls of other crankcase portions of the engine. Conduits connect preselected drain openings to associated orifice check valves to pump the residual oil from the collecting regions to the cylinder walls of other crankcase portions using differential pressures that occur naturally between the associated crankcase portions. The drain openings located at the collecting regions can be located directly under primary oil entry points of the crankcase portions, but this relationship is not absolutely necessary as long as the drain openings are placed at the collecting regions or, alternatively stated, as long as the drain openings are placed at locations where oil will tend to flow from the points of primary oil entry into the crankcase portions.

Abstract: An internal combustion engine is provided with fluid passages between adjacent cylinders. The fluid passages extend through walls that separate adjacent cylinders and are located axially within the cylinders at positions which advantageously define the periods when the fluid passages are blocked and unblocked by pistons moving within lower cylinders. Pressure differentials between adjacent crankcases cause pooled liquid lubricant to be pumped downward through the fluid passages and placed in liquid communication with the walls of the lower cylinder. This pumping action removes pooled lubricant from the transfer passages of one cylinder and causes the liquid lubricant to flow along the walls of a lower cylinder.

Abstract: An oil reservoir is used as a sound attenuator in an outboard motor and is placed under the cowl of the outboard motor with the throats of the engine's throttle bodies disposed between the oil reservoir and the engine itself. This allows the sound emanating from the throttle bodies to be attenuated by the oil reservoir which is cup-shaped to partially surround the throat of the throttle bodies. A plate member can be attached to a hollow wall structure in order to enclose a cavity therebetween. The structure therefore serves as an oil reservoir for the engine and also as a sound attenuating member.

Abstract: A lubricating system for an internal combustion engine is provided wherein oil flows from a compressor oil drain port to a region of the engine which is to be lubricated. The source of lubricating fluid, such as the compressor, is transmitted through a first conduit between the compressor and a lubricant supply region of the engine block. The lubricant supply region is located between a first seal region, or labyrinth seal, and a region to be lubricated which can be a center main bearing. The region to be lubricated is located between the lubricant supply region and a first lower pressure region of the engine, such as the crankcase region associated with one of the cylinders of the engine. A check valve is used to resist flow of the lubricating fluid in a direction from the lubricant supply region to the lubricating fluid source.

Abstract: An oil lubrication system for a marine outboard motor including an internal combustion engine. The oil lubrication system includes a series of oil passageways within the cylinder block of the internal combustion engine. The oil passageways are configured such that each cylinder in the internal combustion engine is supplied by its own oil passageway. Each of the oil passageways terminate in an outlet opening. The outlet opening is positioned within the cylinder block such that oil exiting the outlet opening is directed by the force of gravity into contact with a moving component of the internal combustion engine. As the internal components of the internal combustion engine move, oil contacting the components is physically distributed into contact with the bearings.

Abstract: The cowl of an outboard motor is provided with resilient pads that are disposed on opposite sides of a steering mechanism with a purpose of reducing vibratory motion of the cowl when an engine is operated at idle speed. The resilient pads are held in place by brackets which are attached to the lower cowl of the outboard motor. The two resilient pads are disposed on opposite sides of the swivel tube head of the steering mechanism.

Abstract: An induction system for supplying air-fuel mixture to a two-stroke cycle crankcase compression engine is disclosed. The induction system includes an induction passage for each crankcase compartment, and a reed valve system disposed between the induction passage and the crankcase compartment. The reed valve system includes a reed block having a plurality of valve ports, with the ports being arranged in oppositely spaced sets. The ports are preferably arranged so that the ports in one set are radially opposite the ports in the other set. A single reed valve member is disposed between the induction passage and the crankcase compartment for normally closing the valve ports. The single reed valve member includes a series of petals extending outwardly from a central portion, with a section of reduced area therebetween for reducing the stiffness of the reed valve member.

Abstract: The assembled evaporable pattern, which is substantially identical in shape to the cast metal two-cycle engine block, includes a plurality of in-line cylinders each having an end open to the crankcase end of the pattern. Each cylinder includes an exhaust passage that communicates with an exhaust manifold that extends to the exterior of the pattern and each cylinder has at least one longitudinally extending transfer passage. The assembled pattern also includes cooling passages that surround each cylinder, as well as surrounding the exhaust manifold passage. The foam pattern is composed of a plurality of separate foam sections joined together by an adhesive along planar interfaces. A first of the sections extends from the crankcase end of the pattern to the lower end of the transfer passages, and a second section extends from the lower end of the transfer passages to a location intersecting the exhaust passages of the cylinders. A third section extends from the exhaust passages to the cylinder heads.

Abstract: An exhaust system for an outboard motor (10) includes a main exhaust passageway (16) extending through a partially water filled chamber (17) in the drive shaft housing (13). An inlet idle relief passage (23) connects the top of the chamber (17) with the main exhaust passageway (16) and an outlet passage (24) connects the top of the chamber (17) with the atmosphere. The system thus defines an effective exhaust silencer for the idle exhaust.

Abstract: A latch for the cowl of an outboard motor engine (13) includes a catch (15) mounted on one of the cowl member (12). A lever (19) is pivotally attached to the other cowl member (11) and a resilient spring member (22) is pivotally attached to the lever (19). The lever (19) and spring member (22) act to provide an overcenter action on the lever (19) when the latch is closed. The lever (19) includes a shield (29) to conceal the latch assembly.

Abstract: The invention provides an induction system for supplying air-fuel mixture to a two-cycle, crankcase compression engine (10). A single carburetor barrel (18) supplies mixture to each crankcase compartment (15) through a reed valve assembly having a plurality of reed valve members (29) arranged in a circular pattern. An axially symmetric passage leads from the carburetors (17) to the reed valves and has a generally conical flow modifying body (40) projecting forwardly from the reed valves.

Abstract: A three cylinder, two-cycle engine 10 has a tuned exhaust system formed in a die-cast cylinder block 14. The exhaust manifold is formed by a cavity on the exhaust side of the cylinder block 14 with an exhaust gas outlet passageway 30 formed in the head end of the block 14.

Abstract: A two-cycle engine (10) has an idle fuel system which admits fuel-air mixture into the transfer passages (22). Heated air is supplied to the idle mixing passage (42) by a serpentine air passage (45), while fuel from the carburetor float bowl (33) is supplied through a needle valve (50). A reed valve (43) admits the idle mixture to the transfer passage (22).

Abstract: An induction system for a V-type two-cycle crankcase compression engine (10) with a vertical crankshaft (14) uses two-barrel carburetors (17) with the barrels (19) horizontally adjacent to supply air-fuel mixture to the engine (10). A crankcase compartment (15) is provided for each cylinder (11), the compartments (15) being in a vertical row and surrounding the crankshaft (14). A carburetor adapter or inlet manifold (18) connects each carburetor barrel (19) to one of the crankcase compartments (15).

Abstract: A latching apparatus for cowls on outboard motors which catches and locks automatically, but can be released by simply pushing with one hand. Two sawtoothed semi-rigid mating parts are oriented with leading edges and mating teeth facing in a manner so that they interfere slightly when mated. As the parts approach each other, opposing teeth ride on each other and slip past one after another until all teeth interlock. Release is accomplished by a slight force transverse to the latching motion, thus disengaging the teeth and allowing withdrawal.

Abstract: A two-stroke internal combustion engine having at least three cylinders includes an exhaust means with an exhaust cavity, an exhaust port at each cylinder and an exhaust port extension forming a chamber between the exhaust cavity and the exhaust port. Within the exhaust cavity exhaust pulse transmission means connect the port extension of an exhausting cylinder and the port extension of a charging cylinder with a pulse transmission path of a proper length to cause the exhaust pulse from an exhausting cylinder to arrive at the exhaust port of a charging cylinder prior to the complete closing of the exhaust port of the charging cylinder thereby forcing the air fuel mixture which escaped from the exhaust port of the charging cylinder and which is within the chamber thereof back into the charging cylinder prior to the closing of the exhaust port of the charging cylinder.