Baron - its not the control surfaces that is doing it it is the lack of weight at the front...

with the 63 this plane is balanced like a shocky.... no significant heany lumps anywhere except around the middle... plus overall of course it weighs bugger all for its wing area.

when I say it needs the right hands on the stick with this set up I mean to do a proper freestyle routine. It does the 3D stand up stuff easy peasy but you need to stich it together with other stuff and make it look like you will not run out of power. There is JUST enough in your 90 - reminds me of my 50 with the Mag 61... enough to t'roll and slowly pull out of the top. Not a lot of margin for down low error where a normal pump on the throttle will get you out of there - although the lighter wing loading assists to a greater extent.

The important point is that iut has successfully proved a point...... you can fly a fairly larger than average 90 2str machine on a YS 63 and have great success.

As I said before, these models are so well balanced that extremes in the engine range are possible..

C90 - you really can do (I believe) from a 63 4 str (as we know) up to a 120 FS - and in the right hands a 140 ! Why not - Paul Carr flys a 50 with a 90 FX - same as Ultimate used in the Proto 90 ! Its all about that left stick (M2) !!!