Abstract: An outboard motor having a high-performance V-type twin overhead cam four-cycle internal combustion engine. The oil reservoir for the engine is disposed in a driveshaft housing below the engine and an oil pump is driven off the lower end of the engine crankshaft for circulating the oil from the oil tank to the engine. The oil supply system for the engine includes a vertically extending main gallery and a drain passage which extend in parallel side-by-side relationship and which are disposed over the oil tank for ease of oil return. The exhaust and cooling system for the engine is configured so as to minimize heat transfer between the exhaust system and the lubricating system and to maintain a compact assembly.

Abstract: A throttle sensor senses the position of an associated throttle shaft in order to determine the position of a corresponding throttle valve. The position of the throttle sensor is positioned in the engine to reduce the girth of engine. In one embodiment, the throttle sensor lies to the side of a throttle linkage which interconnects a plurality of throttle valves. The throttle sensor and throttle linkage are arranged on a side of an intake manifold opposite a side on which fuel injectors of the engine are located. In another embodiment, the throttle sensor lies at an upper end of the intake manifold and is coupled to a common, vertically oriented throttle shaft that operates a plurality of throttle valves.

Abstract: A number of embodiments of high pressure pumps for internal combustion engines having vertically extending output shafts. In each embodiment, the high pressure pump has its pump driving shaft rotatable about an axis that is parallel to the crankshaft axis and is driven by the crankshaft. This arrangement lends itself to application in outboard motors. The high pressure pump includes an integral lubricating pump for lubricating components of the high pressure pump.

Abstract: A number of embodiments of a personal watercraft are disclosed which have a catalytic exhaust system for treating and purifying exhaust gases. In all of the embodiments, the catalyst is positioned and disposed so as to be protected from water. In addition, arrangements are provided for cooling the catalyst, for discharging at least a portion of coolant upstream of the catalyst, for circulating ventilating air across it, for isolating it from other components such as the fuel tank, and for permitting its flushing with fresh water after operating in a salt water environment.

Abstract: A two-cycle, direct injection, internal combustion engine provides improved performance by using a portion of energy produced by the production process to heat the engine. The engine includes a plurality of direct fuel injected cylinders and a fuel injection control system. The control system includes a sensory system which detects several operating parameters of the engine, such as, engine speed and intake air flow. An electronic control unit receives input signals from the sensory system and determines the operational condition of the engine. Based on the determined operational condition of the engine, the electronic control unit controls throttle opening degree, fuel injection amounts and timing, and ignition timing. At operating conditions below a preselected engine speed/load condition, the electronic control unit maintains a generally constant throttle opening and fuel injection amount to produce a desired air/fuel ratio.

Abstract: Feedback control systems for engines employing combustion condition sensors. The feedback control is varied in response to various other parameters such as back pressure, engine speed, engine temperature, engine load and initial start-up operation so as to provide more accurate control under varying and transient conditions.

Abstract: An engine of an outboard motor includes an improved induction system, including an intake silencer mounted to a plurality of induction pipes. The intake silencer includes a first and second expansion chamber separated by a wall. The wall includes an aperture for communicating the first and second expansion chambers. A filter element is provided for the aperture for preventing debris from entering the second expansion chamber and induction pipes. The induction pipes are integrally formed in an induction pipe casting. The induction pipe casting and air intake silencer deliver air to a carburetor assembly. The induction pipe casting and carburetor assembly are sealingly engaged through a seal plate and plurality of seals disposed between the induction pipe casting and carburetor assembly for providing an air-tight seal therebetween.

Abstract: A bearing carrier and ring nut of a marine outboard drive both attach to a lower unit of the drive by rotating them in the same direction. The bearing carrier includes a threaded front end which screws into a threaded aperture within the lower unit. A ring nut locks the bearing carrier in place by screwing into a hole on the rear face of the lower unit. A locking tab washer desirably locks the ring nut in place. Because the threads on the bearing carrier and the ring nut are of the same hand, the ring nut does not loosen the bearing carrier when threaded into the hole of the lower unit rear face.

Abstract: A feedback control system for an internal combustion engine that includes an arrangement for determining when the output of the fuel-air ratio sensor may not be desirable for main engine control, and switches between an open control and a feedback control in response to those conditions. In addition, transitional running is improved when operating after long predetermined low-speed running so as to result in a quicker return to the desired fuel-air ratio.

Abstract: A number of embodiments of outboard drive systems that include a combined vertically extending drive shaft driven by the propulsion unit and which drives a generally horizontally extending drive shaft that drives a propulsion device positioned substantially rearwardly of the transom. The propulsion system is supported for steering and trim movement about respective spaced apart axes and these axes are both disposed substantially below the transom of the associated watercraft.

Abstract: An engine mount for resilient mounting an internal combustion engine in a watercraft hull. The engine mount comprises a pair of cradle shaped members that are rigidly affixed to the front and rear underside of the engine and which are mounted at opposite sides of the engine on the hull by resilient cushions that permit resilient vertical movement of the engine relative to the hull.

Abstract: A combustion control system and method for operating an internal combustion engine to provide the desired air/fuel ratio under all running conditions. The system includes a feedback control which received output from an oxygen sensor coupled to one of the combustion chambers of the engine, the feedback control operating to modify the fuel/air ratio from that achieved by a basic setting that is derived from parameters of engine performance so as to maintain the desired ratio. The system also includes a mechanism for controlling backfire during operation of the feedback control. Backfire corresponding to the cylinder including the sensor is controlled by the system in a manner independent of the feedback control. Backfire corresponding to all other cylinders may be controlled independently of the feedback control or by changing overall feedback control parameters.

Abstract: An engine of an outboard motor includes an improved engine component layout to minimize the size of the engine and to generally isolate a shift position mechanism from an intake air flow into the engine. The outboard motor includes a shift actuation mechanism that shifts a transmission between three operational states: forward, neutral, and reverse. The shift actuation mechanism includes a shift position mechanism that defines the position of the shift actuation mechanism during each of these three operational states. The shift position mechanism is positioned beneath the engine crankcase and is formed in part by a shift lever of the actuation mechanism. This position and construction simplifies the design of the shift position mechanism and generally isolates the mechanism from any salt water or other contaminates the are entrained in the air flow stream within the cowling.

Abstract: A control system for an internal combustion engine that includes a fuel injection system. The fuel injection system is monitored in the event of certain abnormalities, either warnings and/or adjustments in the amount of fuel injected are made to compensate for the abnormality. The abnormality may be by sensed by determining the voltage in the actuating coil of the injector or the input signals to the injector. In addition, certain other abnormality controls, such as knocking and temperature controls, are incorporated.

Abstract: A feedback control system for an internal combustion engine that employs a combustion condition sensor for feedback control. The output of the sensor is checked periodically, either by changing the fuel-air ratio and determining if the output changes or by seeing if the output is constant during periods of constant running conditions; and if the sensor is determined to be inaccurate, another control method is employed.

Abstract: A four-cycle outboard motor embodying an improved lubricating system. The lubricating system drains oil from the cylinder head back to the oil tank, in a manner so as to not add to the length of the engine. In addition, an improved crankcase ventilating system is employed that incorporates a simple baffle arrangement for ensuring that oil thrown by the crankshaft rotation will not pass through the ventilating passage into the cylinder head or escape from the ventilating system.

Abstract: An internal combustion engine particularly adapted for driving a vehicle, such as a watercraft, that includes accessories and an engine management system for controlling certain functions of the engine electrically. In order to prevent misadjustment in the event of low available battery voltage, a number of arrangements are depicted for maintaining battery voltage when the normal battery voltage falls. This may be done by increasing engine speed when operating in neutral, discontinuing the operation of other accessories and/or switching a second battery into the power circuit. In addition, an arrangement is provided wherein a battery may be supplied for utilization in starting of the engine to avoid depletion of the main battery's voltage so that the engine control can be maintained even during starting.

Abstract: A trim adjusting system for a small jet propelled personal watercraft. The trim is adjusted automatically in response to sensed water conditions which will indicate, among other things, the condition of the water flowing through the water inlet opening of the jet propulsion unit. The measured conditions may include water condition, watercraft speed and watercraft trim angle. The arrangement also permits manual operation and the permissible range of trim adjustment is less in manual operation than in automatic operation.

Abstract: A number of embodiments of feedback control systems for maintaining the desired air fuel ratio in a marine propulsion engine that has an exhaust system for exhausting the exhaust gases to the atmosphere through an underwater exhaust gas discharge and wherein the discharge is adjustable relative to the associated watercraft. Conditions which will change the back pressure in the exhaust system are measured and the amount of fuel air ratio supplied to the engine by a feedback control system is varied, depending upon the sensed airflow and the sensed condition of the exhaust outlet that may affect back pressure and, accordingly, the ideal air fuel ratio. Spark ignition timing is also changed and the air fuel ratio may be corrected depending upon exhaust back pressure.

Abstract: An outboard motor packing structure convertible to a display stand, having a rectangular parallelepiped formed with rod members, which rod members include first side rods on both right and left sides connecting the front and back rods, in which an end of each first side rod is detached from the front rods and connected to the bottom rods when the packing structure accommodating an outboard motor therein is converted to a display stand by disjointing parts of the rods, wherein the outboard motor is in the same position as when installed in a boat.