I'm putting together a UCD3D and was wondering if anyone is flying theirs with a YS120? I have a NIB 91FZ but I heard or read somewhere that it is just a little under powered for this plane. If you are running a 120, did it balance out ok? Thanks.

I have a YS120SC on mine. I cut a hatch in the rear of the fuse, just in front of the elevator servo on the right, I think, and put my 5 oz battery, and an additional 6-7 oz in there. That seems to be a happy between being a pig to land (I had another 6-7 oz in there) and also being fun in the air. Tank is mounted on CG, throttle servo and RX behind tank. If you see Franz out there in Moreno Valley, he can confirm it flyes quite well.
DKjens

Alrighty, thanks for the info. I think I'm going to install the 91. I have two planes that I use the 1.20 and don't feel like making it three planes. I'm going to lighten up the UCD a bit and just run the 91. Thanks again.

There's been several guys on here that have stated that their U-Can-Do 3D flies great with a Saito 100. I'm sure the YS 91 will have as much juice as the Saito 100, probably a little more. I have this plane with a Saito 100, haven't flown it yet. I went with the Saito instead of the YS for the weight savings. If the engines were close in weight I would have bought the YS. I was just trying to be as light as possible. But, if I'd had a YS 91 on hand I would have used it without blinking. I think either of these engines will fly the plane well. The YS weighs 6 or so more ounces than the Saito 100, but after what I've read on here I don't think it will be a problem at all. I've seen it fly with an OS 91FX and it flew real nice with plenty of power. I'd say a ST G90 would fly it well. I think a 1.20 in either 2 or 4 stroke would be a bit much, but if you want a rocket go for it. I saw a guy fly one with a Saito 1.80, there was a lot of vibration making it's way to the control surfaces with that monster on it! Talk about overkill! I'd read up on the weak landing gear block. This area needs a little reinforcement. There's a couple of threads here on RCU that goes into detail about this and a few other things. You may have already read them. This is just my opinion, hope it helps in some way. Gosh, I feel like I'm writing a book here!