ORIGINAL: Ed_Moorman
#1. I firmly believe that Unbalanced it correct. You should not test or demo the plane with a larger engine than advertised. I think it will limit your sales since the regular guy, and buyer, will think it has to be overpowered to be able to fly well.
A manufacturer has to assume that a substantial number of buyers of 1.20 size 3D capable airplanes will put 1.60s or 1.80s in them. He MUST test with the larger engines to find out whether the plane with stay together with the larger engines installed. If he only tests with the recommended engines, and the overpowered examples start falling apart in the field, word of mouth will destroy him, not to mention that he will have no defense to any damage claims.
Jim