Abstract: An outboard motor incorporating a mounting assembly for resiliently connecting the steering shaft to the driveshaft housing. The mounting assembly also includes locating an attachment bracket on the driveshaft housing juxtaposed to a box shaped section of the internal cavity of the driveshaft housing.

Abstract: A two-cycle crankcase compression, direct injected internal combustion engine having several embodiments of feedback control systems. In each embodiment, the feedback control system includes at least one combustion condition sensor such as an oxygen sensor. The sensor is mounted, however, so that it communicates with the combustion gases through a sensor port that is disposed so that it will not receive fuel sprayed from the fuel injector. In one embodiment, the sensor port is positioned in a common portion of an exhaust manifold upstream of an exhaust control valve. In another embodiment, the sensor port is disposed directly in the cylinder but adjacent the injector so that the spray from the injector will be away from the sensor port.

Abstract: The present invention is an improved oil reservoir for an outboard motor. The oil reservoir is defined by an oil pan portion of an exhaust guide. The exhaust guide includes a support portion which is positioned below an engine powering the motor. The oil pan portion extends downwardly from the support portion. An opening provided in the support portion of the exhaust guide leads to the oil reservoir, serving as an oil return. Preferably, a gasket positioned between the exhaust guide and the engine partially obscures the opening, preventing backflow of oil from the reservoir into the engine when the motor is titled.

Abstract: A fuel injection system for an internal combustion engine provides a uniform flow of gaseous and liquid fuel to each of the intake passages of the engine. A balance passage interconnects each of the intake manifolds to each other and balances the pressure within the intake passages. A pressure regulator regulates the fuel pressure at the fuel injector. A reference pressure chamber within the pressure regulator communicates with the balance passage and controls the fuel pressure based on the balanced pressure within intake passages. The balance passage also communicates with a vapor separator of the fuel supply system that separates liquid fuel from gaseous fuel. The balance passage promotes even distribution of the gaseous fuel to the intake passages. The fuel injection system also includes plenum chamber that acts a source of air for the engine. The plenum chamber includes an drain outlet that communicates with the balance passage for returning blown back fuel from the plenum chamber to the intake passages.

Abstract: A cooling system for an outboard motor propelling a watercraft and powered by an engine, is disclosed. The cooling system includes a first cooling system comprising a coolant flow path through the engine and an oil cooler for cooling the engine and oil of the lubricating system. The cooling system includes a second cooling system comprising a water path from the body of water in which the motor is operating to a heat exchanger and thereon to a discharge back to the body of water. The first cooling system includes two branches, one branch which passes through the heat exchanger and a second branch which does not. A control is provided for routing the coolant through the first branch for cooling within the heat exchanger when the coolant is hot, and for routing through the second branch when the coolant is cool, allowing the engine to warm up.

Abstract: An engine feedback control for an internal combustion engine having at least two combustion chambers is disclosed. When a sensor detects a high engine temperature condition of the engine, the feedback control changes the air/fuel ratio of the air and fuel supplied to each combustion chamber in a manner which prevents operation of any combustion chamber in a disabling range.

Abstract: A transmission arrangement reduces internal stresses and friction within a coupling that links a shift operator with a counter-rotating clutch element of a dual clutch assembly. The shift operator, which interconnects the dual clutches, includes a gap in the connection between the clutches to interject a small degree of play between the clutch elements. The resulting clearance compensates for any adverse tolerance stack-ups which otherwise would produce significant friction between the coupling and the counter-rotating clutch element. The degree of play within the assembly, however, is not so large as to affect the smoothness of the transmission when shifting.

Abstract: An internal combustion engine having at least one variable volume combustion chamber with an intake passage leading thereto, an ignition element for igniting an air/fuel mixture in the chamber, an exhaust passage leading therefrom and including a catalyst in communication therewith, and an emission control for controlling the emission content is disclosed. Preferably, the emission control comprises a mechanism for closing the intake passage leading to the chamber in the event an engine abnormality is detected and an engine ignition misfire mode is employed, thereby preventing the emission of unburned air and fuel into the exhaust passage leading to the catalyst.

Abstract: Several embodiments of feedback control systems for either two or four-cycle engines that employ sensors such as oxygen sensors. The systems include an arrangement wherein the sensor condition is determined by comparing the response time with a normal response time. If the time of response is outside of the normal range, compensation may be made so as to permit continued feedback control. Embodiments are also describe that adjust the maximum permissible injection amount and also revert to an open control if the deterioration is more any predetermined amount.

Abstract: A fuel supply system for an engine powering an outboard motor is disclosed. The fuel supply system includes a pump for supplying fuel from a tank to a vapor separator. Another pump delivers fuel from the vapor separator to at least one charge former for supplying fuel to the combustion chamber(s) of the engine. The fuel supply system includes a mechanism for reducing the transmission of vapor to the pump which delivers fuel to the charge former(s). In one embodiment, this mechanism is a vapor relief line extending to a point outside of a cowling of the motor in which the engine is positioned. In another embodiment, the mechanism is a pump control, and in yet another, the mechanism is a vapor separator cooling system.

Abstract: An oxygen sensor and sensor mounting arrangement for a control system of an internal combustion engine is disclosed. The oxygen sensor senses the actual combustion conditions in a combustion chamber. An insulating arrangement is provided including an insulated conduit and an insulated sensor body for maintaining high temperature of the sensor element by avoiding heat transfer from the conduit and sensor body to the engine body.

Abstract: An outboard motor for a watercraft includes a simply structured fuel supply system of a smaller size and a longer life than prior fuel supply systems. The fuel supply system includes a delivery fuel tank carried by the outboard motor. Fuel is pumped from an external fuel supply tank carried by the watercraft to the delivery fuel tank by a low-pressure fuel pump located within the outboard motor. A control system controls the low-pressure fuel pump so that a predetermined level of fuel is maintained in the delivery fuel tank. The control system includes a fluid level detection sensor that detects the level of fuel within the delivery fuel tank and produces a corresponding signal indicative of the fuel level. A control unit circuit receives the fluid level signal and determines if the fluid level in the tank is higher or lower than a predetermined maximum fuel level. If the fluid level is determined to be higher than a maximum fuel level, the control unit circuit deactivates the low-pressure fuel pump.

Abstract: A catalytic exhaust system for an outboard motor having an engine positioned in a cowling thereof is disclosed. The exhaust system leads from an exhaust port of the engine to a discharge from the motor. A catalyst is positioned in the exhaust system for catalyzing exhaust gases. A first port is positioned in the exhaust system downstream of the catalyst through which an exhaust gas probe may be selectively extended for obtaining an exhaust gas sample. Additionally, a second port is preferably provided between the catalyst and the first port and through which an exhaust gas temperature sensor extends.

Abstract: A number of embodiments of an exhaust system for outboard motors that includes a trap portion in a conduit which conveys the exhaust gases from an expansion chamber formed in the drive shaft housing to an underwater exhaust gas discharge. The trap portion has a horizontal section that is disposed above the water level, and various orientations are depicted. In addition, a catalyst is also provided, and the catalyst is protected from water also by the construction.

Abstract: An arrangement of an exhaust gas collection port within an exhaust system of a small watercraft increases the accuracy of an associated probe's readings. The port is located upstream of a point where cooling water is introduced into the exhaust system for silencing purposes. As a result, the ingress and egress of exhaust gases flow into and out of the port is generally unimpeded by the cooling water. The tendency of water to enter and clog the port is also reduced. The precision of the associated exhaust probe measurements consequently is greatly increased.

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 shifting mechanism that shifts a transmission between three operational states: forward, neutral, and reverse. The shifting position mechanism is principally positioned directly beneath a flywheel of the engine. This position simplifies the design of the shifting mechanism and reduces the girth of the engine and associated components within the cowling.

Abstract: An electrical system is disclosed for a watercraft powered by an outboard motor with an internal combustion engine having a block defining a crankcase at one side and having a cylinder head generally positioned on an opposite side thereof, the engine oriented such that an output shaft thereof extends vertically. The electrical system includes a starter and generator mounted generally alongside the crankcase of the engine and between the ends thereof, the generator driven by a flexible belt extending in engagement with the output shaft, and the starter motor positioned for engagement with a flywheel positioned on the output shaft of the engine.

Abstract: The present invention is an apparatus and method for detecting an operating condition of an oil pump of the type utilized in an oil supply system for a internal combustion engine. The apparatus includes a sensor for detecting the movement of a piston and/or a check valve of an oil pump. The apparatus preferably includes an engine control for monitoring the sensor over a fixed time interval and determining whether a signal is indicative of a malfunction or abnormality. In accordance with the method, the pump is monitored with the sensor and in the event an abnormality is detected, a warning indicator is activated and/or the engine is shut off.

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 gasses.

Abstract: An induction system for an outboard motor of the type having a water propulsion device powered by an internal combustion engine positioned within an engine compartment defined by a cowling, is disclosed. The induction system includes a cover extending over a top end of the engine. The cover defines an air duct leading from an intake chamber defined by the cowling to an intake pipe of the air intake system of the engine. The cover also defines an air duct in communication with the engine compartment and leading to an exhaust chamber defined by the cowling. A pair of intake ports lead through a cover of the cowling from the intake chamber, and an exhaust port leads through the cover from the exhaust chamber. The intake ports are positioned forward of the exhaust port when considering the forward movement of a watercraft which is powered by the motor.