I can see tears on the horizon. This is a bad move for several reasons. Yhe UCD has no forgiveness at all. And from what I have heard (through this site in the pattern forum) that the YS's can be very finicky. They are good engines but are very labout intensive. I think if he really wants to use the plane to get a decent 60 2-stoker and use that. And fly always on a buddy box with an instrucer untill he can fly the beast on his own. Then install the YS and go for it.

I still think in the long run a good trainer will cost him less. With out all the breakage he will go through with the UCD. He will also learn faster with atrainer also. I wish him well in whatever he chooses.

Mark Shuman