Hi Matt........Joe I agree right up until the O.S. comment. LOL - I have the O.S. 91 four stroke inverted and not a drop out of the carb when refueling. I'm using a fuel valve which may be why. No problems with backfiring, or the prop coming loose. Using an APC 14/6 prop so no hand starting. Hasn't happened after 50 + flights. Engine is running very well with unlimited vertical. Do a short take-off and then let the elevators rip and it's no stop to heaven. LG is holding up very well.

I got out this afternoon and flew the UCD and my Giles for several hours. It was a beautiful afternoon with variable puffs and clear skies. No photos on this trip, but had a great time flying and had the skies mostly to myself.

Hey Joe, can you flat spin (upright or inverted) your UCD? I can't seem to get mine to flap spin. I climb and then do a snap at the top and she just goes into a normal spin. I haven't moved anything back on the CG as of yet. This may be the culprit.