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 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 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: A number of embodiments of outboard motors employing direct fuel injection systems having high pressure fuel pumps that are mechanically driven off of the engine crankshaft. A wide variety of driving arrangements are disclosed which include direct and indirect drives and drive that employs flexible transmitters and other types of driving arrangements. Furthermore, the pump operating mechanisms are also provided with lubricating systems that will permit servicing of the lubricant even though the drive arrangement may be positioned outside of the crankcase of the engine. Furthermore, arrangements for mounting various components including the fuel pump and other engine-driven accessories in an outboard motor are shown.

Abstract: A marine propulsion engine abnormal condition sensing arrangement, specifically a low oil pressure sensor, that is effective to permit a low cost sensor by using a separate power supply circuit that need not pass through the main watercraft control in order to drive the switch. The warning device that is operated by the switch is provided with a separate power supply so that its characteristics need not determine the current that is supplied to the sensor.

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 crankcase ventilating gases follow a circuitous path through the crankcase chamber, 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 gases. 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. Portions of this unit are formed from a synthetic resin.

Abstract: The present invention is an ignition control system controlling ignition firing timing of an ignition element associated with an engine. The engine includes an output shaft powering a water propulsion device, an intake system including a throttle valve, and a sensor providing an output signal corresponding to each revolution of the output shaft. The ignition control system calculates a base ignition firing timing from a time between successive previous output signals, and determines if a low-temperature idle condition of engine exists from the sensed throttle angle and coolant temperature. If such condition exists, the ignition control system also determines a compensation value to compensate ignition timing to either the advance or delay side to generally match a target engine speed for a given coolant temperature, and modifies the basic ignition firing timing by the compensation value.

Abstract: A water cooled four-cycle outboard motor having an improved flushing system that permits flushing of the cooling system without removal of even the protective cowling and which permits flushing to be accomplished with a minimum of water usage. The flushing connection is coupled with a tell tale connection to provide a simple, but highly effective construction. In addition, the system effectively cools the engine and a temperature sensor is positioned in an area where it will be protected from overheating.

Abstract: A shock absorbing arrangement integrates in a compact manner into a fluid motor of a tilt cylinder, and consequently is particularly well suited for a small outboard drive that may only have a slimed tilt cylinder. The shock absorbing arrangement is provided in a piston for permitting flow from the first chamber to the second chamber upon the application of a predetermined force tending to cause the outboard drive to tilt-up. The shock-absorbing mechanism comprises a check valve assembly accommodated in a hollow space that is formed in the piston and is closed by a plug attached to the piston. A piston rod extends through the first chamber from the piston and is separately formed with the piston. The piston rod includes a passage that communicates with the hollow formed in the piston. A diameter of the passage provided in the piston rod is larger than the diameter of a valve seat for the check valve assembly in order to reduce fluid friction loss across the shock-absorbing valve assembly.

Abstract: A marine propulsion control that permits the use of transmission braking for a watercraft without the likelihood of engine stalling by increasing engine speed during this condition. Nevertheless normal idle speeds can be maintained when running in neutral. This is accomplished with a single lever control.

Abstract: An outboard motor having a multi-cylinder four-cycle, internal combustion engine as a power plant. The engine is provided with an oil reservoir in the upper portion of the drive shaft housing and lower unit. Oil is drained back to this oil reservoir by separate drain passages formed in the cylinder head and in the crankcase. In addition, an improved crankcase ventilating system is provided wherein the crankcase ventilating gases follow a circuitous path through the crankcase chamber, camshaft chambers and then to the intake system so as to reduce the emissions of hydrocarbons.

Abstract: A cowling arrangement for an outboard motor for use in powering a watercraft is disclosed. The motor has an engine and a water propulsion device, the engine having an output shaft arranged to drive the water propulsion device. The cowling defines an engine compartment in which the engine is positioned and an air chamber having an inlet. The cowling comprises a cover and an air chamber base. The air chamber base is connected to the cover in a sealed manner and divides the engine compartment from the air chamber and includes a duct which extends upwardly into the air chamber. The air chamber base which defines an air passage leading from the chamber to the engine compartment. The air chamber base defines a surface sloping in a direction of a drain through the air chamber, whereby water drawn through the inlet is drained therefrom.

Abstract: A number of embodiments of engine control for marine application wherein the engine is called upon to operate for long periods at speeds substantially below normal idling speed. This is encountered when trolling. The arrangement includes a system for substantially retarding the spark to assist in shifting and also to maintain stability when running at these low speeds. Adjustments may be made in air flow and fuel supply amounts so as to further augment the smooth running and avoid stalling under these trolling conditions. Various control routines for achieving appropriate ignition timing under the widely varying instantaneous speeds during trolling are also disclosed.

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.