Abstract: A propeller device is provided with vent apertures and plugs which fit into the vent apertures to be retained in position during use of the propeller device. The vent plugs are provided with openings therethrough so that fluids can flow from a region within a hub of the propeller device to a region proximate the outer cylindrical surface of the hub. The fluids flowing from the internal portion of the hub flow towards regions of low pressure near the propellers. The plugs can be changed to modify the size of the ventilation aperture without having to change the propeller device itself. One embodiment of the plug is provided with a moveable cover that closes the opening progressively in response to increasing rotational speed of the propeller device.

Abstract: A marine propeller including a hub rotatable about a longitudinal axis and having a plurality of blades extending outwardly from the hub. Each of the propeller blades includes a fixed propeller blade stem and a removable cup extension. The cup extension defines the trailing edge of each propeller blade and is removably mounted to the propeller blade stem. The cup extensions can selectively be removed from the blade stems and new cup extensions attached in order to modify the amount of cupping included on the propeller.

Abstract: A marine fuel injection system for a two cycle crankcase compression internal combustion engine includes a puddled fuel return line (44) having an outlet (44b) in the excess fuel return line (43) from the fuel injector (24) and pressure regulator (26) to the vapor separator (33) and high pressure fuel pump (25) for recirculation. Excess fuel return flow creates a vacuum at the outlet (44b) of the puddled fuel return line (44) to suction puddled fuel therethrough for recirculation together with the excess fuel to the fuel pump (25). The end (44d) of the puddled fuel return line (44) at the outlet (44b) extends within and parallel to the excess fuel return line (43) to occupy a portion of the cross sectional area of the latter to reduce such cross-sectional area and create a venturi in the excess fuel return line (43) at the outlet (44b) of the puddled fuel return line (44).

Abstract: A marine drive (2) is provided with an anti-ventilation plate (22) having a forward horizontal portion (24) and an aft portion (26) extending downwardly at an angle (28) to horizontal and noncoplanar with the forward portion (24). An adjustable anti-ventilation plate (30, 58) is also provided. The preferred form of the adjustable anti-ventilation plate is particularly simple and readily added to existing structure.

Abstract: A marine propulsion system (10) with a depending gear case (20) having water inlet openings (28) is provided with water intake scoops (44) for increasing the flow of water to a water pump (16). Each scoop (44) is provided with a water-receiving opening (46) leading to a passage (52) provided therein for passing water through the scoop toward the water pump. The head portion (48) of each scoop protrudes from the gear case (20), and the water-receiving opening (46) is spaced outwardly from the gear case (20) to provide an active water pickup from the flow of water past the gear case (20).

Abstract: A marine propulsion system (10) with a depending gear case (20) having water inlet openings (32 and 34) is provided with water intake plates (62 and 64) covering the water inlet openings (32 and 34) and having outer forward lips (66 and 68) spaced forwardly and outwardly of the water inlet openings (32 and 34) and outwardly of tapered gear case sections (36 and 38) leading to such openings. The water intake plates (62 and 64) define with the gear case (20) entrance cavities (70 and 72) around the water inlet openings (32 and 34), trapping additional water and directing same inwardly into the water inlet openings (32 and 34) for increasing water flow to a transverse passage (30) and to the water pump (16).