Abstract: An engine apparatus comprising an internal combustion engine having a cylinder with an exhaust port, an exhaust gas passageway system communicating with the exhaust port for providing a first compressive wave arriving at the exhaust port prior to closure thereof, and an exhaust gas side branch for providing a second compressive wave arriving at the exhaust port after the first compressive wave and prior to closure of the exhaust port.

Abstract: Disclosed is a two-cycle, internal combustion engine including an engine block, and a cylinder in the engine block having a head and generally opposed inlet and outlet walls respectively including at least one intake port through which a fresh charge is admitted into the cylinder and at least one outlet port through which exhaust gases are exhausted from the cylinder. A piston is mounted for reciprocative movement inside the cylinder between a first position spaced from the cylinder head wherein the intake port is uncovered, a top dead center position, and a third position wherein the piston approaches the top dead center position. The piston has a top, an inlet face portion which periodically covers and uncovers the intake port and an outlet face portion which periodically covers and uncovers the outlet port. The piston and cylinder have a configuration causing increased swirling of the fresh charge in the cylinder as the piston moves from the third position to the top dead center position.

Abstract: The invention includes an outboard motor comprising a power head having an exhaust gas port, a drive shaft housing extending downwardly from the power head and including an exhaust gas discharge outlet adjacent its lower end, and a continuous folded passage housed in the drive shaft housing. The folded passage includes a first passage portion having an upper end communicating with the exhaust gas port a second portion extending upwardly from the lower end of the first portion and having an upper end, and a third portion communicating with the upper end of the second portion. The folded passage functions to return to the exhaust port as positive pressure pulses the pressure pulses emitted by the exhaust ports, the folded passage causing return of the pressure pulses in timed relation with respect to closing of the exhaust port to thereby facilitate precompression of the fuel mixture entering the cylinder.

Abstract: A powered device has a center of gravity and includes an engine comprising a block member, a crankshaft having opposite first and second end portions, and generally spaced supports on the block member for supporting the crankshaft for rotation with the first end portion extending toward the center of gravity and the second end portion extending beyond the supports. A piston is located in the block member for reciprocative movement, and a connecting rod has a first end portion pivotally connected with the piston and a rotationally balanced second end portion rotationally connected with the crankshaft intermediate the supports for converting the reciprocative movement of the piston into rotation of the crankshaft about its axis.