Why beat your heads against the wall? YS has been proven to be the best for serious pattern work.

Many years ago, I went through a similar phase of trying to use OS for pattern. Folks, they just weren't up to the task. Rossi and YS did it much better, if you could manage to get your hands on an engine.

The "best" OS engines for pattern were the SF/RF 10cc engines and then the Hanno Special engines. However, by that time the 20cc YS four-stroke ruled as King. Larger iterations still do.


Ed Cregger