Perfirmance has improved compared to the previous O.S. SPEED 21XZ-GT.
Refine the cracnkcase of the R2101 which got an excellent rersults on on-road racing.
Cylinder / piston adopt scavenging 5 port + exhaust 3 port which cleared IFMAR regulation.
Stroke volume： 3.49cc / 0.213 cu.in.
Practial rotation speed: 4,000-42,000 r.p.m.
Weight: 369g / 13.02oz