For a long time, the 11x7 was considered a good starting point for .61 two strokes. Over the last several years, more and more people say they are running them on .46 engines. My brother had a TT46Pro on a Big Stik 40 and the prop that he felt gave the best performance was an APC 11X5.

Like gboulton wrote, you have to experiment to find what YOU like because your opinion is the onlyone that counts when it is your plane and your money involved.