Abstract: A marine propulsion device comprising an internal combustion engine including an engine block comprising a cylinder, an idle exhaust inlet port, an idle exhaust outlet port communicating directly with the atmosphere, and an idle exhaust passage communicating between the idle exhaust inlet port and the idle exhaust outlet port, a drive shaft housing, a propeller shaft rotatably supported by the drive shaft housing and adapted to support a propeller, a drive shaft extending through the drive shaft housing and including an upper end driven by the engine and a lower end drivingly connected to the propeller shaft, and an exhaust housing located at least partially within the drive shaft housing and connected to the engine, the exhaust housing including a main exhaust passage communicating with the exhaust outlet port, and an idle exhaust passage communcating between the main exhaust passage and the engine idle exhaust inlet port.

Abstract: An engine block comprising a first crankcase-defining member including a first semi-cylindrical surface having an end and extending about a first center, and also including a first shoulder extending radially outwardly from the end of the first semi-cylindrical surface, a second crankcase-defining member fixedly connected to the first crankcase-defining member and including a second semi-cylindrical surface located in generally co-planar facing relation to the first semi-cylindrical surface having an end and extending about a second center located in spaced relation to the first center, and also including a second shoulder extending radially outwardly from the end of the second semi-cylindrical surface, a crankshaft supported by the engine block and including a crankcase-defining disc including a cylindrical surface in spaced and generally co-planar facing relation to the first and second semi-cylindrical surfaces and including therein an annular groove, a first seal member located in the annular groove and h

Abstract: Disclosed herein is an inner exhaust gas housing adapted to be located within a drive shaft housing of an outboard motor, which inner exhaust gas housing integrally includes an open upper end, a first exhaust passage extending downwardly from the upper end, a second exhaust passage extending downwardly from the upper end, an expression chamber adjacent the upper end, a first passage communicating between the first and second exhaust passages and the expansion chamber, and a second passage communicating with the expansion chamber and with the atmosphere exterior to the inner exhaust gas housing.

Abstract: A marine propulsion device comprising a lower unit including a rotatably mounted propeller, an internal combustion engine mounted on the lower unit and drivingly connected to the propeller, the engine including an engine block, a crankshaft and flywheel assembly including a crankshaft rotatably supported by the engine block and having an end extending from the engine block, and a flywheel mounted on the end of the crankshaft for rotation therewith, and a voltage generator including a magnet mounted on one of the assembly and the engine block, and a coil mounted on the other of the assembly and the engine block, the coil being radially spaced from the magnet, and an annular power takeoff pulley mounted on the flywheel and surrounding the voltage generator in adjacent relation thereto axially of the crankshaft.

Abstract: A marine propulsion device comprising an internal combustion engine including a coolant conduit having an upstream conduit portion, a downstream conduit portion, and a passage portion extending between the upstream portion and the downstream portion.

Abstract: An air silencer for an internal combustion engine including a fuel hose and an intake manifold supporting a carburetor, the carburetor including an end including a carburetor intake. The air silencer comprises a base member including a first opening, a second opening adapted for extension therethrough of the carburetor, and an opening for passage into the air silencer of the fuel hose, and the base member is mounted on the intake manifold independently of the carburetor. The air silencer also comprises a cover member removably mounted on the base member, and a baffle member removably mounted between the base member and the cover member to form a silencing chamber between the cover member and the baffle member, the baffle member including an opening adapted to communicate with the carburetor intake, and a silencer tube communicating between the first opening in the base member and the silencing chamber.

Abstract: The two-cycle internal combustion engine has a sump in a lower portion of the crankcase for collecting engine fuel drains and a crankshaft bearing lubrication system including a first conduit means connecting the upper crankshaft bearing in communication with the engine intake manifold, second conduit means connecting the upper crankshaft bearing in liquid communication with the sump and having an intermediate portion or reservoir, and third conduit means connecting the crankcase in communication with the reservoir. A first check valve located between the sump and the reservoir permits fuel drains to flow from the sump upwardly toward the upper crankshaft bearing in response to a suction created in response to the low pressure or vacuum in the intake manifold and prevents backflow from the reservoir to the sump.

Abstract: Silencer apparatus for an internal combustion engine including an intake manifold, the apparatus comprising an air silencer having a lower end including a sump, and a conduit extending upwardly from the sump to the intake manifold for purging the sump of fluid only when the engine is operating.

Abstract: Shifting of a marine propulsion device transmission drivingly connecting a drive shaft to an internal combustion engine and including a rotatable member operable to shift the transmission between forward drive, reverse drive and neutral positions in response to rotation of a shift lever is assisted by a shift assistance arrangement including a pivotal actuation lever connected to a push-pull assembly operated by a main control and a connecting link pivotally connected to the shift lever and to the actuator lever. The pivotal connection between the connecting link and the actuation lever includes a slider element mounted for reciprocative axial movement relative to the connecting link and pivotally receiving a pivot pin on the actuation lever. A pair of springs acting on the opposite ends of the slider element maintain the connecting link and the actuation lever in a normal position so they move together to effect shifting when the resistance to transmission shift is below a predetermined level.