Abstract: An exhaust system for a marine engine uses an orifice to distribute liquid coolant flow between two alternative and parallel paths. One coolant path passes through a generally horizontal portion of an exhaust elbow and the other coolant path passes through the orifice and directly to a vertical riser of the exhaust elbow. The ratio of flow between the two paths changes as a function of engine speed because of the operation of the orifice which provides increased resistance to flow as a function of increased pressure drop across the orifice. Although coolant liquid continues to flow through both paths at all times, the relative magnitudes of the two parallel flows are changed in response to changes in the coolant flow into the elbow which, in turn, changes as a function of engine speed.

Abstract: A heat exchanger for a marine internal combustion engine is disposed between first and sides of a V-shaped engine configuration. A plurality of tubes and related structure are disposed within a cavity formed as an integral part of an air intake manifold of the engine. A first cooling fluid, such as ethylene glycol, is circulated in thermal communication with outer surfaces of the plurality of tubes within the heat exchanger and a second cooling fluid, such as lake or sea water, is circulated through the internal passages of the plurality of tubes. A conduit is provided within an end portion of the heat exchanger to remove heat from a lubricant, such as oil, of the internal combustion engine.

Abstract: An idler pulley is provided with a plurality of attachment locations, or holes, extending through a hub portion of the pulley to allow the pulley to be attached to a stationary object in a plurality of alternative configurations in order to provide a way for adjusting or selecting the tension of a belt used in conjunction with the idler pulley. Threaded fasteners pass through selected attachment locations of the hub portion of the idler pulley and are threaded into anchor locations on a stationary object, such as an internal combustion engine.

Abstract: A hydrostatic marine propulsion system is provided with a valve that is able to bypass an infinitely variable amount of hydraulic fluid from a hydrostatic pump to bypass a hydrostatic motor which is used to drive a propeller shaft. The infinitely variable valve is connected between the hydrostatic pump and the hydrostatic motor with dual outlets which cause fluid to flow either to the hydrostatic motor or to a reservoir to be recycled through the hydrostatic pump. An engine control unit changes the amount of hydraulic fluid passing through the hydrostatic motor as a function of the operating condition of an engine which drives the hydrostatic pump. In this way, engine speed can be controlled during various modes of operation.

Abstract: A fuel supply system is provided with a heat exchanger disposed in a generally planer cavity within a base. A manifold attaches to the base and contains the generally planer cavity. A heat exchanger, which comprises a fuel conduit, is disposed within the cavity. As fuel flows from a fuel pump to a fuel injection system of an internal combustion engine, it passes through the fuel conduit which is bathed in a flow of coolant. Some of the fuel flows directly from the fuel conduit to the fuel injection system, but excess fuel flows through a pressure regulator and a filter before being passed through the pump again to recirculate through the fuel conduit of the cooler. The quantity of fuel stored within the volume of the fuel supply system is significantly reduced because of the location of the various components and the fact that the components, such as the filter, regulator, and pump are attached directly to the base of the system.

Abstract: A fuel supply system for a marine propulsion system having an electronically controlled fuel injection system eliminates the need for a vapor separator. The system pumps an excessive amount of fuel through a plumbed fuel supply loop and cools recirculated fuel to cool all the components in the plumbed fuel supply loop, i.e. a continuous duty, constant displacement fuel pump; a pressure regulator; and a water separating fuel filter. Recirculated fuel flows from the pressure regulator to the water separating fuel filter as does make-up fuel from a fuel tank. The fuel stream from the water separating fuel filter flows to the low-pressure side of the fuel pump, which pumps the fuel through the plumb fuel supply loop. A fuel injection portion of the fuel flows to the engine for combustion, while the remaining portion of the fuel is recirculated. The recirculated portion of the fuel is cooled, preferably using a water-cooled heat exchanger.

Abstract: An injection-molded, plastic fuel distribution insert for an internal combustion engine having a wet manifold promotes complete fuel atomization and vaporization. The fuel distribution insert also provides for even fuel distribution to the various combustion chambers. The fuel distribution insert preferably has a flange integral with one or more downwardly extending shrouds. Each shroud defines a subchamber having a volume substantially less then the volume of the manifold plenum. A fuel-air mixture from a fuel-air supply source enters into the shroud at the inlet of the intake manifold and is retained within the shroud until the mixture exits one or more exit windows in the shroud. The exit windows in the shroud are placed to promote even fuel distribution.