ORIGINAL: piroflip2
I have a Perry V20 pump on my 120AX with the tank on the C of G and it never misses during 3D or pattern (U-can-do 60). I also have a YS110. It has shaken two good airframes to bits (magnetic balanced prop) and I will never buy another.
I had a ys 110. i replaced it. i did not like it at all, it needed at least 25% nitro for a reliable idle and to generate good enough power for what i want. the os 120ax has much more power and i do not mind buying a pump to make it run perfect. thanks for your input.