I just bought my first YS engine, it's a 110FZ, and I must say, I'm impressed!! It turns a 15X8 APC @ 9500 static with YS 20/20 fuel and an O.S. F plug. The idle is also impressive just keeps clicking them off at 2100 NICE!! It should be even more impressive with the 30% heli fuel.

It's going in a Hangar 9 .60 size mustang, the OS .91 that is is replacing would turn a 13X8 @ 10200 with 30% heli fuel. don't get me wrong the OS runs great but it won't keep up with the other YS powered warbirds!

On the dependability issue, I too have seen guys wrestle with YS engines at the field, as I have seen people wrestle with O.S , Saito, Thunder tiger, Super tiger, magnum, ect, ect...

edited for typos