I fly YS engines in my planes so I pulled the OS out of my Raven and put the YS 50 in as soon as I could get one. I can tell you this much as I am still breaking mine in, this thing is a monster.

I had the same issue you did, it would hang or flameout on transition. After chasing my needles all over the place I arrived at this. My low speed needle is at 1 1/8 turns out and the high speed needle is at 1 1/4 turns out. The YS engines I have tuned always were slobbering rich at the recommended needle HS needle setting and this one is no different. It is just easier to tune an airplane engine since you can make changes while it is running

I am running the same Powermaster YS 20/20 mix I use in my 4 stroke YS engine with no issue, an OS #8 plug and a Youngblood MP2 pipe.

I gave a friend of mine my old OS 50 for his Raven and he was there when I first fired up my YS. To say the least he was impressed and so was I. The head speed is up a noticable amount and I will have to modify my thottle and pitch curves.

Just be aware that these needles are EXTREMELY SENSITIVE so make minor adjustments.