Abstract: A shutter valve construction for the exhaust system of a marine engine that discharges exhaust underwater. The valve construction includes an adaptor having an annular body that is adapted to be engaged in the end of an exhaust pipe. Opposite sides of the body are provided with outwardly projecting bosses which are received within holes in the exhaust pipe to position the adaptor relative to the pipe. The valve construction also includes a butterfly-type shutter valve that consists of a pair of valve members which are hinged to a hinge pin that is removably connected to the adaptor. To connect the valve to the adaptor, the ends of the hinge pin extend into opposed openings in the body of the adaptor and receive resilient grommets.

Abstract: A flame arrestor (70) for a marine engine (12) includes an air box (72) mounted to the combustion air intake (14), and a uniplanar flame arresting element (78) mounted to the air box (72) and passing combustion air therethrough in a first direction (80) into the air intake (14) and blocking flame propagation in a second opposite direction out of the air intake (14). Air flow from the flame arresting element (78) to the air intake (14) is rectilinear.

Abstract: An apparatus for separating solid material from cooling water in the cooling system of the engine block of a marine engine. The engine block comprises a plurality of cylinder bores surrounded by a cooling passage through which cooling water is pumped. The bottom portion of the block includes a drain outlet that communicates with the cooling passage and a tubular separating member has a first generally horizontal section that is sealed within the drain outlet. The tubular separator also includes a second section that is located within the cooling passage and extends downwardly from the inner end of the first section and is located between two adjacent cylinder bores. The lower end of the second section is closed and a port is provided in the side of the second section adjacent the closed end and facing toward one of the cylinder bores.

Abstract: A sea water pump (130) for a marine propulsion system includes a housing (130) having a generally cylindrical pumping chamber (134) defined by a generally cylindrical sidewall (136) extending axially between opposite end walls (138 and 140). A multi-vaned rotary impeller (44) in the chamber is driven by an impeller shaft (28) extending axially into the chamber through one of the endwalls (40). An intake port (146) at the other endwall (140) has a first branch (148) providing radial flow (170, 172) into the chamber, and a second branch (154) providing axial flow (178) into the chamber. A discharge port (158) has a first branch (160) receiving radial flow (174, 176) out of the chamber, and a second branch (166) receiving axial flow (180) out of the chamber.

Abstract: A drain valve assembly for automatically draining water from a cooling system of an inboard marine engine when the ambient temperature drops to a preselected value. The drain valve includes a cup-shaped base having a group of inlets connected to portions of a cooling system of the engine to be drained, and the open end of the base is enclosed by a cover. Each inlet defines a valve seat and a sealing piston is mounted for movement in the base and includes a series of valve members that are adapted to engage the valve seats. An outlet is provided in the sidewall of the cup-shaped base. The valve members on the sealing piston are biased to a closed position by a coil spring and a temperature responsive element interconnects the sealing piston with the cover. The temperature responsive element is characterized by the ability to exert a force in excess of the spring force of the coil spring when the ambient temperature is above about 50.degree. F., to thereby maintain the valve members in the closed position.

Abstract: An apparatus for separating solid material from cooling water in the cooling system of a marine engine. The apparatus includes a hollow member or housing having an inlet to receive cooling water and having an outlet. A drain opening is located in the housing above the bottom surface of the housing and is connected through a suitable conduit to a temperature responsive drain valve. A generally J-shaped tubular member is disposed in the housing and has one end connected to the drain outlet while a second end is slightly above the bottom surface of the housing, out of alignment with the inlet. When the drain valve is open, water will drain through the housing to the drain outlet, while solid debris will collect in the bottom of the housing beneath the second end of the tubular member.

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.