Abstract: A control system for an outboard motor is disclosed. The control system includes a feedback control which obtains feedback data from a combustion condition sensor. The motor includes an engine positioned in a cowling and having a vertically extending output shaft in driving relation with a water propulsion device of the motor. The engine has at least one combustion chamber and an air/fuel charging system for delivering air and fuel into the combustion chamber for combustion therein. The motor includes an exhaust system for routing exhaust from the engine to a point external to the motor. The exhaust system includes an exhaust passage leading from the chamber to a main exhaust passage which extends vertically downward to an exhaust guide positioned below the engine. A passage leads from the exhaust guide into an expansion chamber and thereon to an exhaust discharge.

Abstract: A cooling system for an outboard motor having a water propulsion device and an internal combustion engine positioned in a cowling, the engine having an output shaft arranged to drive the water propulsion device, is disclosed. The cooling system includes a coolant delivery mechanism driven by the engine, the delivery mechanism arranged to deliver coolant of at least one coolant passage of the engine. The cooling system also includes at least one coolant drain line through which coolant may drain from the engine and a control which controls the flow of coolant through the drain line after the engine is stopped.

Abstract: An outboard motor exhaust system and control for insuring good running and effective exhaust gas silencing and treatment. The system includes a very compact exhaust system that includes an expansion chamber formed beneath the exhaust guide plate and to which the exhaust gases are delivered and removed at optimal locations. Furthermore, a feedback control employing a combustion condition sensor is employed along with a catalyst in the exhaust. Sensors are provided upstream and downstream of the catalyst to ensure that it is operating at optimum conditions.

Abstract: An ignition arrangement for an internal combustion engine having an output shaft supported for rotation about an axis. The engine includes an engine housing at least partially enclosing the output shaft. Oil seals at least partially surround the output shaft for sealing the output shaft to the engine housing. An oil seal housing at least partially surrounds the output shaft and at least partially engages the oil seals. The oil seal housing directly supports a first ignition component.

Abstract: A marine outboard drive that is equipped with integrated splash plates and a baffle plate that prevent water splash-up along the drive shaft housing. The baffle plate protrudes from the drive shaft housing to interact with plates on the lower bracket to create a labyrinth effect. The labyrinth created by the splash and baffle plates impedes the path of any water impinging upon the lower bracket and the drive shaft housing. This minimizes the amount of water travelling up the drive shaft housing. A splash plate may also be included on the lower bracket to minimize water flow above the lower bracket.

Abstract: Two embodiments of outboard motor constructions that employ an improved mounting arrangement for certain electrical components such as ECUs and rectifier regulator units. The mounting arrangement places these components in proximity to the intake system for the engine so that the flow of intake air to the engine will assist in cooling the electrical components. A shrouding arrangement is also provided so as to protect the components from water vapor while not inhibiting the cooling air flow.

Abstract: A drive arrangement for an engine of an outboard motor including a cowling and a water propulsion device is disclosed. The engine is positioned in the cowling and has a body having a top end and a bottom end and defining at least one combustion chamber. The engine has a generally vertically extending crankshaft having a bottom end in driving relation with the water propulsion device and a top end extending above the top end of the body of the engine, the engine including an intake system including an intake passage through which air is provided to each combustion chamber, at least one intake valve for controlling the flow through the intake passage, and an intake camshaft for actuating the intake valve(s). The engine also includes an exhaust system including an exhaust passage leading from each combustion chamber, at least one exhaust valve for controlling the flow of exhaust through the exhaust passage, and an exhaust camshaft for actuating the exhaust valve(s).

Abstract: A crankcase ventilation arrangement for an outboard motor that permits ventilating air and blowby gasses to flow from the crankcase chamber into an induction system of the engine for air purification. In addition, the arrangement is such that oil, which may flow into the ventilating system is separated so that it can return to the crankcase chamber.

Abstract: An oil pump for a lubricating system of an outboard motor is disclosed. The motor has a cowling defining an engine compartment, a water propulsion device, and a guide member having an upper surface and a lower surface, the guide member positioned in the cowling and generally dividing the engine compartment into an upper part and a lower part. An engine is positioned in the upper part of the engine compartment within the cowling and has an output shaft arranged to drive the water propulsion device. The lubricating system includes an oil pan positioned below the guide member and an oil passage leading from the pan through the guide member. The oil pump is positioned in the upper part of the engine compartment, but below the engine, and is driven by a lower end of the output shaft of the engine which extends below the engine, the oil pump having an oil inlet in communication with the oil passage through the guide member.

Abstract: An improved hydraulic circuit for a tilt and trim adjustment system allows an associated marine drive to be trimmed up into a tilt range for running in shallow water. The circuit includes a tilt relief valve. The valve differentiates between the hydraulic pressures within the system caused by various running conditions, and opens the valve only when two conditions are met: (i) the associated pump is activated and (ii) high pressure exists at the valve's inlet side, which usually occurs when running at high speeds. The valve, however, remains closed at slower speeds. The marine drive thus can be raised up and operated within the tilt range, provided that the speed is slow enough.

Abstract: A number of the embodiments of exhaust systems and oil tank arrangements for four-cycle internal combustion engine powered outboard motors. In all of the embodiments, idle exhaust gases are discharged to the atmosphere through a path that extends above the oil tank. A cooling jacket is formed around an exhaust pipe that depends through a cavity in the oil tank and coolant from this cooling jacket is discharged to the exterior surface of the exhaust pipe so as to cool it. Cooling water from the engine and from the exhaust pipe cooling jacket is isolated from the idle exhaust gas discharge so as to ensure that this cooling water cannot enter the engine through the idle exhaust gas discharge path.

Abstract: A fuel injection system for supplying fuel from a fuel source to an internal combustion engine having at least one combustion chamber, the engine preferably powering an outboard motor, is disclosed. The fuel injection system comprises at least one fuel injector for supplying fuel to the combustion chamber of the engine, a pump delivering fuel at high pressure to at least one fuel rail arranged to deliver fuel under high pressure to the at least one fuel injector, a pressure sensor for detecting a pressure of the fuel in the fuel rail, and a valve controlling a by-pass passage through which a portion of the fuel pumped by the pump may be selectively diverted away from the fuel rail, based upon the fuel pressure detected by the pressure sensor.

Abstract: An engine of an outboard motor includes an improved engine component layout to minimize the size of the engine and to improve the performance of the components. A separator of a crankcase ventilation system is located on a cam cover outside the cam chamber in order to reduce the size of the cam cover while providing the necessary spacing between the separator and the valve mechanism within the cam chamber. A fuel pump is positioned at about the center of the cam cover, beneath the separator, to generally balance the length of fuel travel to each of the carburetors. A fuel filter also is located on the cam cover, beneath the fuel filter, to generally isolate the fuel filter from the effects of the heated cylinder head and block. The arrangement of these components does not interfere with the hinge-like travel of a top cowling, which surrounds the engine, relative to a lower tray.

Abstract: A fuel supply system for an internal combustion engine mounted in a cowling of a marine device is disclosed. The engine has a body defining at least one combustion chamber and an output shaft arranged to drive a water propulsion device of the marine device. The engine has an intake system supplying air to the combustion chamber. The fuel supply system includes at least one fuel injector providing fuel to the engine for combustion with the air. Various configurations for at least two pumps used to deliver fuel from a fuel source to the fuel injector(s) which contribute to reduced vapor production and improved pumping efficiency are disclosed.

Abstract: A number of embodiments of direct injected V-type outboard motors provided with a very effective fuel supply system wherein the number of components can be significantly reduced as well as the elimination of many of the flexible conduits normally employed. This also permits the fuel system to be assembled as a relatively unitary assembly that can be then affixed to the engine. The arrangement is such that purging of the system from vapors during shutdowns is easily accomplished and the system can be purged without complicated construction. Furthermore, the system can be pressure tested by an arrangement where the low pressure system can bypass the high pressure system when the engine is not operating so as to be pressurized for testing purposes. However, when the high pressure system operates, then the bypass line will be closed by the shunting valve arrangement.

Abstract: An outboard motor embodying a twin overhead camshaft, four cycle internal combustion engine as a power plant. The engine has an improved flexible transmitter drive for the camshaft, which permits the drive pulley to overly the end main bearings for the camshafts so as to reduce bending loads on them.

Abstract: An improved and simplified outboard motor construction wherein the exhaust system for the engine is formed with a minimum number of components and sealing joints. The exhaust system includes an elongated expansion chamber formed in the drive shaft housing. In addition, the drive shaft housing has a cylindrical section that is journaled within a swivel bracket for its steering movement. The volume between the external portion of the drive shaft housing and the internal portion of the swivel bracket forms a second expansion chamber that is employed for the low speed above the water exhaust gas discharge. The flow of cooling the water to and from the engine is controlled so that the exhaust gas interchange area between the power head and the drive shaft housing will be well cooled, as will the oil reservoir for the engine.

Abstract: A control for a propulsion unit for a watercraft, the unit powered by an internal combustion engine, is disclosed. At least one sensor is associated with the propulsion unit for providing data regarding a condition of the propulsion unit. The control includes a memory for storing sensor data, an input accepting data from the sensor(s) and storing the data in the memory, and an output for reading data from the memory. The memory has a first data position and a last data position. The control is arranged to store data obtained from the sensor(s) through the input sequentially to the first and through the last data position and to then repeat the sequence of storing back at the first position after the last data position is filled.

Abstract: A fuel system arrangement for an engine positioned in a cowling of an outboard motor is disclosed. The engine has a first end and a second end and comprises a cylinder block with a cylinder head connected to the cylinder block at the first end of the engine and cooperating therewith to define at least one combustion chamber, and a crankcase positioned at the second end of the engine. The engine includes an intake system for providing air to the combustion chamber, the intake system including at least one intake runner extending along a side of the engine defined between the first and second ends, the runner having a passage therethrough leading to a passage extending through the cylinder head to the combustion chamber. The fuel system includes a fuel supply unit for delivering fuel from a fuel supply to at least one charge former, the charge former arranged to provide fuel to the combustion chamber for combustion therein, the fuel supply unit positioned at the first or second end of the engine.