Abstract: A jet propelled watercraft having an improved extension assembly for dampening pulsations from the impeller of the jet propulsion unit and also for mounting the jet propulsion unit. The structure simplifies the overall assembly and permits individual tuning with conventional units.

Abstract: Four embodiments of fuel air injectors wherein variations in the amount of fuel discharged due to the existence of pressure variations between the injector valve and its seat in the fuel injector are minimized. This is done by provided a restricted orifice downstream of the point of fuel injection so that combustion chamber pressures are dampened from the fuel injector. In all embodiments of the invention the injector valve is a poppet valve having a configured stem portion for slideably supporting the poppet valve within the housing while permitting flow therepast. In two embodiments, the fuel is delivered to the injector above the configured portion of the poppet valve and in two embodiments the fuel is delivered below the configured portion of the poppet valve for improving responsiveness.

Abstract: An induction control system for an internal combustion engine and an operator for controlling the control valve. The system operates so as to move the control valve between an unrestricted flow position and another position wherein the flow velocity or direction is changed. The valve is moved between these positions at varying rates depending upon the engine running condition so as to provide quicker response under some conditions than others.

Abstract: A cylinder head arrangement for a direct injected internal combustion engine and particularly one having multiple valves. The cylinder head configuration is such that the injector can be positioned centrally in the combustion chamber and disposed below the overlying ports, which preferably are the inlet ports without significantly detracting from their flow area or without requiring sharp curvature or bends in their configuration that could restrict air flow.

Abstract: Several embodiments of variable valve timing mechanisms for an internal combustion engine wherein the timing of two valves associated with the same combustion chamber of the engine may be driven at the same time interval and at the same speed from the engine output shaft and both valves may have their timing adjusted simultaneously by a first variable valve timing mechanism and only one of the valves may have its timing adjusted relative to the other valve by a second variable valve timing mechanism to provide a simpler operational control and lower cost assembly.

Abstract: A composite piston and method for forming such a piston for a reciprocating machine such as an internal combustion engine. A blank is formed from a pair of dissimilar alloys, one of which has substantially greater properties such as strength or abrasion resistance. The blank is formed by a process whereby he two materials are initially bonded and extruded into a composite blank. The blank is forged into a piston in such a way that the two materials are bonded together in the forging process. The higher strength and/or abrasion resistance material forms at least a part of the outer surface of the piston in areas where the better properties are required. The other material backs up the higher strength or hardness material in necessary areas so as to provide an integral structure that has lightweight, low costs and nevertheless the desired properties.

Abstract: Several embodiments of combustion chamber configurations for direct injected engines having a substantial recess in the cylinder head in which the fuel injector is positioned and injects. The injector is arranged so as to be disposed over the exhaust port and to spray toward the auxiliary scavenge port. However, the spray pattern is such that fuel will not impinge upon the cylinder head surface and so that the scavenge flow will direct the fuel away from the cylinder walls and toward the head of the piston for cooling and better vaporization. This also ensures that fuel will not pass out of the exhaust port.

Abstract: An improved variable valve timing mechanism that is operative to provide an arrangement for varying both the valve lift and lift curve in response to dynamic running conditions. A variable valve timing mechanism is also incorporated in the cam drive so as to further widen the range of adjustment of valve timing.

Abstract: An electric power assisted, manually operated vehicle such as a wheelchair. A force sensor senses the manual input force and the power assist is generated in response to the sensed input force. A number of embodiments are disclosed wherein the amount of assist is varied in response to running conditions and/or operator conditions so as to improve the performance. In many of these embodiments, the assist is greater at low speeds and is held constant at higher speeds and then decreased as the speed exceeds a predetermined high speed. In some of these embodiments, a regenerative braking is also applied in the event the vehicle speed becomes excessive. Also, the null or dead band range of the sensor is adjusted so as to provide a wider range when stationary than when running. This decreases sensitivity for startup and yet provides good response during running.

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 selectively to at least one of two coolant jackets of the engine. One coolant jacket is associated with at least one combustion chamber of the engine. The other cooling jacket is associated with an exhaust manifold for that combustion chamber. The cooling system also includes at least one coolant drain line through which coolant may drain from each of the cooling jackets of the engine.

Abstract: A load detection device according to this invention has a detection section including a magnetization coil (2) and a solid rod-like magnetic substance disposed in the axial center of the magnetization coil (2), the magnetic substance (1) is magnetized by the magnetization coil (2), and load (P) is applied directly to the magnetic substance (1) to produce inductance change, so as to be detected. Therefore, according to this invention, the device is simplified in its construction with a high mechanical strength and a wide dynamic range, capable of effecting smaller size, weight saving and cost reduction, as well as easy handling ability, and suitable for transfer. In addition, the load (P) is detected from inductance change due to change in magnetic permeability of the magnetic substance (1) caused by the load, so that no displacement is accompanied with detection, providing a structure capable of achieving high direct response and easy adjustment with small hysteresis, and unlikely to be affected magnetically.

Abstract: Various embodiments of an exhaust system for an engine powering a water propulsion device of a watercraft having a hull with a front end and a rear end are disclosed. The water propulsion device is positioned near the rear end of the watercraft, with the engine connected to the hull and positioned generally towards the front end of the watercraft from the water propulsion device and having an output shaft arranged to drive the water propulsion device. The exhaust system routes exhaust from each cylinder or combustion chamber of the engine to a discharge at the rear end of the watercraft.

Abstract: A variable valve timing and lift structure for a four-cycle internal combustion engine wherein a high speed and low speed cam are associated with the camshaft, each for operating the same valve. The high speed cam is supported for movement relative to the camshaft and this movement includes relative rotation. A coupling device selectively couples the second cam for rotation with the camshaft so as to operate the valve during at least a portion of its opening and closing movement when so coupled. When the second cam is not so coupled, the first cam controls the entire motion of the valve. The first and second cams are related so that at least one of these cams can operate two adjacent valves for the same cylinder, thus simplifying the overall construction.

Abstract: A push rod operated multi-valve V-type engine particularly adapted for use in motorcycles or like vehicles and which engine is air cooled. The engine employs a very simplified construction and overhead valve actuating mechanism utilizing push rods. The push rods are contained within push rod tubes formed at one side of the engine that provide a neat appearance and ease of servicing without adversely affecting the air cooling. A composite cylinder head construction is employed, as well as an improved lubricating system for the pair of driven camshafts. Furthermore, a decompression system is incorporated in the valve actuating mechanism to lower the compression ratio so as to facilitate starting.

Abstract: An improved journaling and sensor mounting arrangement for the VVT mechanisms of a twin overhead cam engine. By utilizing a combined single bearing cap for the VVT ends of the camshafts that mounts the sensors that are associated with timing wheels on the respective camshafts, it is possible to maintain a very neat external appearance and a compact construction. Also, high accuracy can be obtained because of the positive rotation of the components. In addition, a simplified oil supply and control arrangement is also disclosed for lubricating the thrust surfaces of the camshaft bearings and other bearing surfaces as well as supplying hydraulic fluid to the VVT mechanisms.

Abstract: A variable valve timing mechanisms for an internal combustion engine wherein the timing of two cam shafts associated with the same combustion chamber of the engine may be driven at the same time interval and at the same speed from the engine output shaft and both cam shafts may have their timing adjusted simultaneously by a first variable valve timing mechanism and only one of the cam shafts may have its timing adjusted relative to the other cam shaft by a second variable valve timing mechanism to provide a simpler operational control and lower cost assembly. The variable valve timing cam drive arrangement also reduces the loading on the cam shaft bearings.

Abstract: Several embodiments of personal watercraft having a V bottom hulls that define an engine compartment in which an internal combustion engine is positioned. This engine drives a propulsion device for the watercraft through an appropriate transmission. The engine includes an engine body having an opening into which a fuel injector injects. The fuel injector is positioned so that its spray axis is oriented so that it is not likely to intersect the walls of the engine that define the opening regardless of the angular position of the watercraft in the body of water in which it is operating. Both direct and manifold injected and two and four cycle engines are disclosed.

Abstract: An engine fuel injection system including a supply arrangement that includes a pair of conduits for supplying fuel to the plural injectors. The conduits are interrelated with the injectors in such a way that no one conduit supplies fuel to any two fuel injectors that fire simultaneously with or in sequence with each other.

Abstract: A number of embodiments of induction systems for watercraft that employ, in addition to the plenum chamber of the air inlet device for the induction system, a further plenum chamber of a predetermined volume that communicates with the induction system plenum chamber for providing silencing and/or tuning effects to improve induction efficiency and silencing. In addition there are disclosed compact intake devices that incorporate plenum chambers for this purpose.

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.