Abstract: An outboard motor generally comprises a power head. An engine is mountable within an engine compartment defined within the power head. The engine is lifting into and out of the engine compartment in part through the use of lifting lugs. The engine may have one or more lifting lugs positioned in various locations for use in suspending the engine from ropes or chains during installation. The lifting lugs may attach to an upper surface of the engine, a portion of the flywheel or a drive unit of a high pressure fuel pump. The lifting lugs may also be positioned in dead space such as that between cylinder banks of a v-type engine. Moreover, the lifting lugs may be removable or pivotable to reduce the protrusion of the lifting jugs from the engine when the outboard motor is in use.

Abstract: Several embodiments of the type two-cycle crankcase compression engines having exhaust control valves for controlling the effective compression ratio of the engine. The exhaust control valves are rotatably journaled in respective cylinder banks and are disposed at the same distance from a plane passing through the center of the valley between the cylinder banks as each other facilitating a common drive therefor. In one embodiment the exhaust control valves are disposed on the side of the cylinder banks adjacent the valley and in another embodiment they are disposed on the outside of the cylinder banks.

Abstract: Several embodiments of V-type outboard motors having direct cylinder injection using electronic fuel injectors driven by a solenoid driver. The solenoid driver is mounted in the otherwise void area between the cylinder banks of the engine. The solenoid driver is also cooled so as to provide long life and good operation. The cooling can be either by air or water or both. Mounting the solenoid driver in the valley between the cylinder banks also permits shortening of the conduits from the solenoid driver to the solenoids of the injector valves for their operation.

Abstract: A four-cycle outboard motor has an oil separator positioned within a head cover assembly. The oil separator is positioned within a recess of a cam cover, which forms a portion of the head cover assembly. A cover plate is interposed between the oil separator and a cam chamber. The oil separator includes a generally u-shaped labyrinth through which exhaust gases with entrained lubricant are sucked. A suction portion extends through the cover plate and facilitates communication between the cam chamber and the oil separator. An exhaust return line is connected to an induction system to draw gases through the oil separator back into the induction system.

Abstract: An outboard motor is configured for steering by a tiller arm. The tiller arm is moveable relative to the outboard motor about a transverse axis and is arranged to steer the motor about the vertical axis. The outboard motor further has a power head that contains a vibration engine and is comprised of a protective cowling and lower tray. A tiller arm mounting bracket is secured to the power head and a mounting structure extends from the tiller arm. A resilient member is juxtaposed between the mounting bracket and the mounting structure. A gap is defined between a face of the resilient member and the tiller arm such that the resilient member may freely vibrate within the gap without that face of resilient member contacting the tiller and directly translating vibrational energy to the tiller arm.

Abstract: A fuel injection control strategy and system for engines for maintaining good performance under normal running conditions and also for providing cylinder engine speed slow-down under abnormal conditions without necessitating cylinder skipping except in extreme cases. This control is obtained primarily by retarding injection timing and/or reducing injection duration. Adjustment in spark timing may also be incorporated along with this routine.

Abstract: An outboard motor has a steering lock which retains the rotational orientation of the outboard motor relative to a watercraft. The steering lock allows the motor to be pivoted about a substantially horizontal tilt and trim axis while the steering lock is engaged. The steering lock includes a friction plate which is advantageously straight. The friction plate is connected to the steering arm, and movement of either the steering arm or the friction plate requires movement of the other. At least one friction lock engages with the friction plate to secure the motor in a desired orientation. The friction lock is rigidly affixed to the outboard motor. The friction lock includes one or more disc pads. Movement of an operation lever urges the disc pads against the friction plate hold the friction plate and consequently, the steering arm, in a predetermined position.

Abstract: An outboard motor having a multi-cylinder four-cycle, internal combustion engine as a power plant. An improved crankcase ventilating system is provided wherein the camshaft chambers and then to the intake system through an extended conduit passing over the exhaust manifold so as to reduce the emissions of hydrocarbons. The intake system is designed to preclude uneven distribution of the ventilating gasses. The intake system also is comprised of a plenum device, a plurality of runners and throttle bodies and an intake manifold that are attached as a unit to the rest of the engine body. Locating pins assist in this attachment.

Abstract: An engine idle and speed control arrangement incorporating a butterfly-type throttle valve. The throttle valve is disposed so that it is at a relatively small angle to a plane containing the throttle valve axis and extending perpendicular to the direction of air flow through the induction passage. The peripheral edge of the throttle valve is configured so as to avoid binding. Bypass idle air flow is provided around the throttle valve as to provide substantially the entire idle air speed requirements of the engine. This arrangement permits better idle control since the idle air-flow changes will be more uniform in response to given angular changes in the position of the throttle valve.

Abstract: A lubricant supply system is provided for the induction system of a marine propulsion engine. The lubricant supply system delivers lubricant to the a flow controlling valve in the induction system upon shutting down of the engine and can be operated manually at the discretion of a user. The lubricant serves to reduce the likelihood of post-operation corrosion of the valve, particularly at the sliding support surfaces of the valve and also provides lubricant from startup operation.

Abstract: A fuel injection control strategy and system for engines for maintaining good performance under normal running conditions and also for providing cylinder engine speed slow-down under abnormal conditions by cylinder skipping. Transitional operation between these modes is improved by changing injection timing and/or injection duration of the operating cylinders during this time. Adjustment in spark timing may also be incorporated along with this routine.

Abstract: A number of embodiments of feedback control systems for two-cycle, internal combustion engine management systems. Each embodiment employs an exhaust system sensor which senses the exhaust gases by drawing exhaust gases from the exhaust of the engine. In some instances this is done directly from the cylinder and in others it is done in the exhaust system. In each embodiment, the sensor is provided in an accumulator chamber so as to provide an accurate signal of instantaneous engine running conditions. The use of the accumulator chamber insures that the combustible gases will not be diluted with fresh air charge, but will be able to purge from cycle to cycle so as to provide cycle-by-cycle information. Various arrangements are provided for protecting the sensor element including serpentine flow paths, shields, the direction in which the exhaust gases are delivered, lubricant catalysts, conduit shape, sensor cooling and combinations of these features.

Abstract: A protective cowling arrangement provides atmospheric air to the engine of an outboard motor for engine cooling and combustion while inhibiting water intake. The protective cowling incorporates one or more air inlets, an air chamber, and ducts of different sizes for permitting atmospheric air to enter the engine compartment. One of these ducts, which is disposed in part above electrical components of the engine, is substantially shorter in length than the other duct. This duct thus has a smaller flow area without unduly restricting air flow through the duct. An air chamber cover is affixed to the engine and shields the ducts to afford further water preclusion.

Abstract: A piston and piston ring assembly has a compression ring and a compression ring groove configured to allow proper mating between the two following thermal expansion. The groove is provided with a substantially horizontal lower face. The ring has a bottom surface that is contoured to provide a cross-sectional angle that substantially matches the anticipated deflection of the lower face caused by thermal expansion. Thus, when the piston expands due to temperature changes associated with operating the internal combustion engine, the lower face deflects away from the combustion chamber. The deflection is absorbed by the pre-contoured bottom surface of the ring. Thus, localized high points between the piston ring and the piston ring groove are reduced and the friction originating at such locations is also reduced. Accordingly, the ring and the groove experience reduced friction and reduced wear while the sealing function of the compression ring is enhanced.

Abstract: A four cycle outboard motor that have water cooled engines and an oil pan that is formed in the upper portion of the drive shaft housing. An exhaust pipe collects exhaust gases from an exhaust guide and delivers to a cavity that is formed in the oil pan by an interior wall thereof. The exhaust pipe does not terminate below the lower surface of the oil pan and idle exhaust gases are delivered to the area between the exterior of the exhaust pipe and the interior surface of the oil pan that defines the cavity. These idle exhaust gases are discharged to the atmosphere through and above the water exhaust gas discharge. The oil pan lower surface has a drain opening that is aligned with a vertical drain opening in the drive shaft housing.

Abstract: A silencing arrangement for the induction system of an internal combustion engine particularly as applied to an outboard motor. The engine silencing system includes at least one intake silencing valve that controls the emanation of sounds from the interior of the plenum chamber of the silencing device to the atmosphere. This valve position does not restrict airflow under the controlled positions. The valve can be positioned either in response to engine load as determined by factors such as throttle position or by engine speed.

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: A feed back control system for a direct injected, two cycle engine having a catalytic exhaust. The injection control is modified if the catalyst overheats to control its temperature.

Abstract: A feed back control system and method for direct injected engines, particularly useful in marine applications to avoid excessive hunting due to the close proximity of the sensor to the fuel injector. Both injection initiation and duration are controlled under most operating conditions. However, under certain conditions such as when only small corrections in the air fuel ratio are required the control is initially maintained by adjusting the injection timing.

Abstract: An exhaust gas purifying arrangement is provided for an outboard motor for a watercraft. At least one exhaust port is provided which opens into a first exhaust passage having a first catalyst member lining at least a portion of its inner wall. The first exhaust passage then opens into an exhaust expansion chamber. Next, a second exhaust passage originates just beyond the expansion chamber. A second catalyst member is mounted within and across a section of exhaust passage beyond the first exhaust passage and at a location above the water line within which the outboard motor operates. A first passageway is provided which leads from the second exhaust passage, from a position beyond the second catalyst member, to an exhaust outlet located at a position below a body of water in which the watercraft operates.