O.S. .21 XZ-B Speed
O.S. is ready to put another engine on the shelf for you to buy. The .21 XZ-B Speed has all kinds of new features on it. The fuel efficiency of this engine has been improved by 8% over the non-speed version .21 XZ-B. The cylinder head had been made 9mm shorter than the .21VZ-B Speed, the center of gravity has [...]
