A two-stroke internal combustion engine includes at least one gaseous communication charge passage between a crankcase chamber and a combustion chamber of the engine and a piston to open and close the top end of the transfer passage. The air inlet port to the transfer passage for stratified scavenging is opened and closed by the piston that has passages and cutouts. The charge inlet to the crankcase chamber is opened and closed by the piston. The air inlet passage is substantially asymmetrical to the layout of the transfer passages and are closer to one transfer passage compared to the other. The internal air passage in the piston is substantially parallel to the piston pin and the single air inlet passage is laterally off-set from the air-fuel inlet passage. The transfer passages are cover by plates to make them closed passages having opening at the transfer port in the cylinder and opening in the crankcase chamber for periodical gaseous communication between the crankcase chamber and the combustion chamber. The cover plate is a single piece covering the transfer passage channel along the cylinder and the crankcase. The air channel in the piston is below the piston crown and at least portion is above the piston pin. A spiraling transfer passage in the cylinder cavity is longer than the length of the transfer passage in a conventional stratified two-stroke engine.