I built the Royal B-25 kit back in the 80's. Here's the deal. I was probably way over my head when I built this one. But, I agree with Azcat and outlaw, they are builders kits. I built the nose crooked on mine and had to take it apart and do it over. I had fixed gear and Saito .45's for power and it was plenty. The first flight was pretty easy- just a little aileron trim and it was flying hands off. It was a great flying plane, despite that I had a wing warp in it that should have made it unbearable. I checked the incidence (of course, after it was too late to do anything about it) and one tip had -1 1/2 deg. (maybe this was washout) and the other tip had +1 1/2 deg. I was at least prepared to do major trim inputs at take off, but just didn't happen. About half of the aileron trim took care of it.
I was flying it one day, and was coming across the field, and about the time someone hollered "You only have one turning" I noticed it. I remembered about not turning into the dead engine, but due to our field layout, a turn away from the dead engine would have put me behind the pit area and toward a motel, and I wasn't about to find out how big a turn I was going to have to make, so I put in a little left aileron, and it immediately rolled on it's back. I had altitude, so I cut the power and pulled out underneath completing a half loop, and headed for the field. I had it coming straight at me and couldn't tell how fast it was flying. It finally stalled into the corn from about 12' altitude. Apparently the engine quit when I was flying straight and level, because I had no indication it had quit before I saw the prop stopped. I have read before that the twin rudders help with this due to having one in each air stream. Never the less, it was a good flying plane. I was just outside of my envelope at the time. Fixed it back up as a solid nose version and sold it to a couple guys in Ashville, NC.
Randy