Stratified scavenging two-stroke engine

The present invention relates to a stratified scavenging two-stroke engine (10). The stratified scavenging two-stroke engine (10) includes a first scavenging passage (36) that extends from a first scavenging intake (362) that opens to the inside of the crankcase (24) to a first scavenging port (364) that opens to the inside of a cylinder (22), and a second scavenging passage (38) that extends from a second scavenging intake (382) that opens to the inside of the crankcase (24) to a second scavenging port (384) that opens to the inside of the cylinder (22). The first scavenging passage (36) and the second scavenging passage (38) are formed so as to communicate with each other via a communicating portion (44). An air passage (42) is connected to the first scavenging passage (36) at a position closer to the first scavenging intake (362) than the communicating portion (44). A first check valve (46) inhibits a flow from the first scavenging passage (36) to the inside of the crankcase (24), and a second check valve (48) inhibits a flow from the first scavenging passage (36) through the air passage (42) to the outside.