ORIGINAL: TFF
Not a powerhouse, but no 4 strokes in the early 80s were. Dont lug it too much and dont make it scream. Good for sedate airplanes like Cubs or a big Telemaster. Not a 3D or race engine.
Yes, OS's earliest effort at producing a 1.20 sized pattern four-stroke does indeed have a few limitations. But it IS a good engine. I wish I still had my first four-stroke, the OS FS-120.
Ed Cregger