Excellent points talking about the tapered and lack of dihedral wings.

As for the YS, I bought this new from an ex-pattern guy that recently replaced the cup and piston, so the engine already broken in. Ibought a gallon of Wildcat 30% Nitro 23% SynOil from my LHS just for this engine, test ran it last night briefly and it is definitely a powerhouse swinging the 15x8 APC. Ijust need some clear weather and can get this thing flying.