Abstract: A marine transmission mounting system for marine engine and drive that are mounted in a mid-travel position to joists in the hull space between a hull and a floor of the boat. Such a system is typically used on a competition water-ski boat where the engine, transmission, and propeller shaft are mounted in-line at a downward angle with respect to a floor of the boat such that the propeller shaft passes through the hull of the boat in front of the transom. The transmission mounting system includes a transmission mounting bracket having reinforcement webs located above the span of the bracket so that smaller reinforcement webs can be located below the span of the bracket. With such a bracket, there is sufficient room underneath the bracket so that an engine exhaust tube can pass under the bracket. This allows overall engine and exhaust system space requirements above the floor of the boat to be reduced.

Abstract: In a low pressure continuous flow fuel injection system for an internal combustion engine, an electric fuel pump (18) is energized with a variable duty cycle to vary the pumped volume output of the pump according to engine fuel requirements. The duty cycle is varied to energize the pump to pump substantially only the amount of fuel required by the engine, such that at idle or low engine speed, the pump is energized a lower percentage of the time than at high engine speed. Fuel flow through the fuel injector (12) is continuous, but energization of the pump is not, such that the pump is not pumping at full capacity when unneeded. An electric idle air control valve (54) is also energized with a variable duty cycle to vary the amount of bypass idle air supplied to the intake manifold (10).

Abstract: A fuel rail assembly for an internal combustion engine including an elongated rail having a longitudinal inlet passage and a longitudinal outlet passage. The upstream end of the inlet passage is connected to a fuel supply line while the downstream end of the inlet passage is connected through a pressure regulator to the upstream end of the outlet passage. A return fuel line is connected to the downstream end of the outlet passage. A plurality of injector bores communicate with the inlet passage and extend to the exterior of the rail and each injector bore receives one end of a fuel injector, while the opposite end of each injector is sealed within a bore in a runner of an intake manifold. The injectors are mounted in a manner to provide limited tilt to facilitate assembly with the bores in the fuel rail and the manifold reservoir.

Abstract: An improved intake manifold and plenum construction for an electronic fuel injected engine. The manifold includes a plurality of parallel runners, with each runner having a lower end communicating through a port in the cylinder head with a cylinder of the engine, and an open upper end. A fuel injector is mounted in each runner for injecting fuel into the runner. A plenum is mounted on the manifold and includes an upper wall and a lower wall which is spaced from the upper wall to define an air chamber, The upper ends of the runners communicate with the chamber, so that air is drawn from the chamber through the runners to the cylinders.

Abstract: A dual bore throttle body assembly for a marine engine. The assembly includes a body having a pair of side-by-side bores, each of which is adapted to be enclosed by a flat throttle valve. A separate shaft is connected to each throttle valve and a throttle cable is connected to the shafts through a progressive linkage. The linkage is constructed such that only one of the valves is initially opened, and when that valve is approximately 50 percent open, the second valve is then opened. The speed of opening of the second valve is greater than that of the first valve so that both valves will reach the full opened position at the same instant. Each shaft is provided with a longitudinal slot which receives the respective throttle valve, and the valves are secured within the slots by mechanical fasteners such as screws.

Abstract: A vapor separating unit for a fuel system and having particular application to a fuel system for a marine engine. The vapor separating unit includes a closed tank having a fuel inlet through which fuel is fed to the tank by a diaphragm pump. The liquid level in the tank is controlled by a float-operated valve. An electric pump is located within the vapor separating tank and has an inlet disposed in the tank and an outlet connected to a fuel rail assembly of the engine. Excess fuel from the fuel rail assembly is conducted back to the upper end of the vapor separator tank. A vapor venting mechanism is incorporated in the tank to vent vapor from the tank.

Abstract: An optical detector for use in detecting digital optical signals has an optical fiber coupler which splits a received optical signal into two signal portions. The coupler has unequal length output fibers so that one signal portion impinges upon an associated photodetector delayed relative to the other. The photodetectors are connected in series nonopposed when the delay is equal to the bit period of the optical signal the output of the detector is the differential code (dicode) of the received signal which can be recovered by a high input impedance, i.e. integrating, amplifier. By forming the dicode in the optical domain in this manner large DC and AC dynamic ranges are obtained without linearity constraints on the optical transmission source that apply when the optical signal is transmitted as a dicode.

Abstract: Apparatus for stabilizing the output characteristics of an injection laser has a device for producing an electrical pulse train representative of an optical pulse train of the laser. The electrical pulse train is fed to circuitry which monitors the switch-on delay of the laser and controls the bias current of the laser such that the switch-on delay is maintained constant. Alternatively the pulse length can be monitored. The pulse amplitude or mean pulse energy can also be monitored and maintained constant.