SCHNUERLE SCAVENGING TWO-STROKE ENGINE

A Schnuerle scavenging two-stroke engine is provided that can keep combustion stability in a wide rotation speed range while suppressing blow-by. The engine of the present invention is a Schnuerle scavenging two-stroke engine (2). A scavenging passage (14(in1)) related to at least one scavenging port (16(in1)) has, at its upper end portion (14a(in1)), an intake-side wall surface (204). The intake-side wall surface (204) defines a first flow direction (42) of scavenging gas discharged from the scavenging port (16(in1)) at a height level of the scavenging port (16(in1)). The upper end portion (14a(inl)) of the scavenging passage (14(in1)) related to the scavenging port (16(inl)) has a guide portion (50) defining a second flow direction (44) of scavenging gas discharged from the scavenging port (16(inl)). The second flow direction (44) is deflected to the intake side from the first flow direction (42) at the height level of the scavenging port (16(in1)).