Two-stroke engine

A two-stroke engine that executes scavenging by supplying fresh gas pre-compressed in a crank chamber through scavenging ports to a combustion chamber in a scavenging process, comprising:

• at least four scavenging ports,
• the four scavenging ports including:
• first right and left scavenging ports that lie on a side relatively away from an exhaust port and that lie facing each other with a cylinder in between;
• and
• second right and left scavenging ports that lie closer to the exhaust port than the first right and left scavenging ports do and that lie facing each other with the cylinder in between, wherein
• the second left scavenging port and the first right scavenging port that make up a first mutually diagonal set have different opening timings from those of the first left scavenging port and the second right scavenging port that make up a second mutually diagonal set.