ORIGINAL: Walt and Sage
Yes, you are right as it (in MY oppion) is to large for a 25% Yak
I am installing the SPE 43 cc in a 29% Giles U/L witha 78 inch span and 1100 sq inch wing..
It will fly but you may have tip stalling at slower speeds... BE very careful...
You're opinion was dead on. Took off with my SPE 43 and it tip stalled at about 30 feet. Plane was destroyed!!!
RJetss, If I had it to do all over again, I would go with a 26 or 28 cc engine.