Forum looks different, I have to get used to it. I use suction on my 4 strokes and uniflow on my 2 strokes. As to the YS Bob, that was a light hearted joke. The engine is very complex and requires a very high level of expertise in ANY application.
If you are curious, ask Windy for his video with the YS on it. I have also run them courtesy of the RC boys, ("hey guys look at this, he's going to hand start it") .
The YS has a stranglehold on the 2 meter F3A scene, the OS Max 91 Surpass has come to dominate the Senior Pattern Association class, (their classic). Saito dominates everything else. If I was going to rock and roll in F3A,(hint hint) I would go with the Saito FA-150, (hint hint). I would bank on my not having to dead-stick against his better flying to pull out a win LOL.