Two-cycle internal combustion engine

A two-cycle internal combustion engine wherein uncarbureted air is used to purge gases produced by combustion from a combustion chamber prior to feeding carbureted air into same, the engine comprising a first cylinder having an engine piston which moves therein and a second cylinder mounted 180.degree. to the first cylinder in the engine, having a movable balancing device, which moves therein, the inner faces of said engine piston and movable balancing device delimiting the chamber of a crankcase pump, the outer face of said engine piston delimiting said combustion chamber having an inlet and the outer face of said movable balancing device delimiting an auxiliary compression chamber having an outlet, further comprising at least one transfer channel connecting said crankcase pump chamber to said combustion chamber for admitting carbureted air from said crankcase pump chamber to said combustion chamber;

• a first pure, uncarbureted air tube connecting said auxiliary compression chamber to said combustion chamber and having a buffer reservoir therein;
• pure air means for admitting pure, uncarbureted air into said auxiliary compression chamber and for pumping the pure, uncarbureted air through said first pure, uncarbureted air tube into said combustion chamber, at least one carbureted air intake port being connected to said transfer channel and at least one pure, uncarbureted air intake port being connected to said first pure, uncarbureted air tube disposed in the wall of said first cylinder in such a manner that said at least one pure, uncarbureted air intake port is uncovered by the movement of said engine piston from the top of said first cylinder towards the bottom thereof and pure, uncarbureted air flows into said combustion chamber to purge gases therefrom before said at least one carbureted air intake port is uncovered by the same movement of said engine piston piston to admit carbureted air into said combustion chamber which mixes with the pure, uncarbureted air which continues to flow into said combustion chamber via said at least one pure, uncarbureted air intake port.