On the road show
Rotary-Valve Rocket: Kawasaki 350 Avenger A7SS
Offroad bikes of today have nothing on this classic Kawasaki. Meet the ‘69 350 Avenger A7SS. For Japanese motorcycle manufacturers, the 1960s were a time to license, adapt or invent new technology and what resulted was 2-stroke genius. The rotary valves give better control over intake-port timing. Unlike a reed-valve engine, the port opening is completely unobstructed giving the engine a broader power range. In other words? More peak horsepower.
Source: Motor Cycle Classics