Abstract: A multicylinder internal combustion engine is provided with a plurality of cylinders sharing a single crankshaft. The combustion characteristics in the respective cylinders is improved by taking out part of combustion (expansion) gas produced in one of the cylinders at an earlier stage of the explosion (expansion) stroke, and then introducing the gas into another one of the cylinders in the suction or compression stroke.

Abstract: A multicylinder internal combustion engine is provided with a plurality of cylinders sharing a single crankshaft. The combustion characteristics in the respective cylinders is improved by taking out part of combustion (expansion) gas produced in one of the cylinders at an earlier stage of the explosion (expansion) stroke, and then introducing the gas into another one of the cylinders in the suction or compression stroke.

Abstract: A two-cycle internal combustion engine is provided which comprises: a cylinder receiving a reciprocative piston and having a top portion provided with a combustion chamber in which a spark plug faces; an exhaust port laterally opening into the cylinder; at least one first scavenging port opening into the cylinder at one side of the exhaust port; and at least one second scavenging port opening into the cylinder at another side of the exhaust port opposite to said one side. Each of the first and second scavenging ports directs scavenging gas away from the exhaust port. The first scavenging port opens into the cylinder with an upward inclination for directing a first portion of the scavenging gas upwardly toward the top portion of the cylinder, whereas the second scavenging port is oriented to direct a second portion of the scavenging gas transversely of the cylinder toward a wall portion of the cylinder where the first scavenging port is formed.