RE: Bragging about the .55 AX
Today I found that the engine likes a light prop for break in. Every other manufacturer suggests a lighter prop for breaking the engine in, but OS says to use what you plan on flying with. I did that and had a really tough time keeping my engine running (12x8, 13x6, 13x5) then switched to a light prop (12x5) and the engine ran great.
On my 46AX I used an 11x5 for quite a while before switching to a 12" prop. At first the change seemed to bog down the engine, but after a gallon or so it now screams with the bigger prop. I hope the same happens for the 55.