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: 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 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: 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.

Abstract: A number of embodiments of four cycle outboard motors 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 In many embodiments the exhaust pipe does not terminate below the lower surface of the oil pan and several arrangements are disclosed for delivering idle exhaust gases to the area between the exterior of the exhaust pipe and the interior surface of the oil pan that defines the cavity. Various arrangements are disclosed for conveying idle exhaust gases to this area and discharging them to the atmosphere through and above the water exhaust gas discharge. These arrangements incorporate a system for precluding water from entering into the engine through its exhaust system including the idle discharge.

Abstract: An outboard drive is equipped with a water inlet located on a lower casing of the outboard drive. The lower casing includes a nacelle that houses a transmission and a propulsion shaft that are coupled to an engine through a drive train. The propulsion shaft rotates about a longitudinal axis that is aligned with a centerline of the nacelle. The water inlet is located on a front, cone-shaped nose of the nacelle, forward of the transmission and above the longitudinal axis of the of the propulsion shaft. The water inlet communicates with a water passage that guides cooling water to a water pump. The water passage is located in front of the transmission in order to increase the size of the water passage over prior water cooling systems of outboard drives.

Abstract: A throttle control system for an outboard motor and throttle position sensor therefor that permits a compact assembly by operating the throttle valve via an intermediate throttle valve operating shaft that is disposed closer to the body of the engine and farther from the protective cowling than the throttle valve. A throttle position sensor is associated with this intermediate throttle operating shaft for providing a signal indicative of throttle valve position for engine control.

Abstract: An intake manifold for an engine powering a water propulsion device of an outboard motor is disclosed. The engine has first and second combustion chambers and an intake system for delivering a fuel and air charge to each combustion chamber. The intake system includes a first intake passage leading through the engine to the first combustion chamber and a second intake passage leading through the engine to the second combustion chamber, the first intake passage positioned vertically above the second intake passage. The intake manifold is arranged to deliver equal amounts of fuel to the first and second intake passages and includes a main passage extending along a first axis. A first branch defines a passage leading the main passage to the first intake passage, and a second branch defines a passage leading from said main passage to the second intake passage.

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 engine has a body with a top end and a bottom end, the output shaft extending above the top end. A flywheel is connected to the output shaft at the top end of the engine, and a flywheel cover is positioned over the flywheel and supported by the engine body. The cowling defines an engine compartment in which the engine is positioned and has an opening therein. A starter panel is connected to the flywheel and supported solely thereby, the starter panel cooperating with the cowling to close the opening therein, the starter panel supporting at least one component of a starter for the engine.

Abstract: The invention relates to an engine control system for an internal combustion engine for propulsion of an associated watercraft. The engine includes an air intake in communication with a combustion chamber of the engine and an air intake adjustment means for altering the amount of air let into the combustion chamber of the engine. There is also an operation device controlling a water propulsion device of the watercraft. The device is movable between a forward, a neutral or a reverse position. A first control means for controls the air intake adjustment means based upon the position of the movable operating device. A second control means controls the air intake adjustment means independent of the first control means based upon a set of predetermined conditions.

Abstract: The present invention is an overheat detection system for an engine having at least one cooling jacket which is drained of coolant when the engine stops running. The detection system includes a sensor for sensing a temperature associated with the cooling jacket. The detection system is arranged to output an overheat signal in the event the temperature sensed by the sensor is above a predetermined temperature except within a predetermined time after the engine has been started.

Abstract: A number of embodiments of personal watercraft having catalytic exhaust systems for treating and purifying the 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 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 fuel system for an internal combustion engine powering an outboard motor of a watercraft is disclosed. The fuel system includes a main fuel source and a pump for delivering fuel from the main fuel source through a fuel filter to a vapor separator. Fuel is supplied from the chamber by high pressure pump through a fuel rail to one or more fuel injectors. Undelivered fuel is returned to the vapor separator through a return line. Oil is mixed into the fuel between the fuel filter and the high pressure pump, so that the high pressure pump draws a mixture of fuel and oil and delivers it to the charge former(s) and fuel return.

Abstract: A choke control for an outboard motor having a cowling, a water propulsion device and an internal combustion engine positioned in the cowling and arranged to propel the water propulsion device is disclosed. The engine has at least one combustion chamber and an intake system including an intake pipe extending along a side of the engine for providing air to the combustion chamber. A choke control is provided for actuating a choke valve associated with the intake pipe. The choke control includes a choke actuator which is positioned exterior to the cowling and supported by a mount associated with the cowling, the choke actuator connected to the choke valve via a choke linkage which is positioned within the cowling generally above the intake pipe.

Abstract: A vapor separator for an outboard motor is disclosed. The outboard motor has a cowling and a water propulsion device. An internal combustion engine is positioned in the cowling and arranged to propel the water propulsion device. The engine includes a top and a bottom side. The engine also includes an engine block defining at least one cylinder bore therein. A crankshaft is supported for rotation with respect to the engine block and is located in a first chamber. A camshaft is supported for rotation with respect to the engine block and is located in a second chamber. The engine further includes a lubrication system for the lubrication of the crankshaft and the camshaft. A lubrication collection area is located on the bottom side of the engine for the gravitational collection of engine lubrication fluid from the first chamber and the second chamber.

Abstract: An induction system for an internal combustion engine powering an outboard motor, the motor having a cowling and a water propulsion device and the engine positioned in the cowling and having an output shaft arranged to drive the water propulsion device, is disclosed. The engine has at least one combustion chamber, and the induction system is arranged to provide air to each combustion chamber. The induction system includes an intake duct having an inlet and an outlet and defining an air flow path extending from the inlet to the outlet, the inlet defining an opening through which air is drawn, the outlet arranged to deliver air passing through the duct to an intake passage leading to the combustion chamber. At least one electrical component associated with said motor is connected to the intake duct and extends into the air flow path defined therethrough, whereby the at least one component is cooled by the flow of air through the duct.