I had the Evolution .46NT in mine and I had no problems with the engine. I had both the PNP and the ARF version. I also have the .46NX and the .61NX. And again my engines run good as my O.S. .91FX Ringed, without the extra cost. The trick is to get your engines on a engine stand, remove the safety stoppers on your high and low end mixture screws including the blue collar, and break in your engine and fine tune it when you are done. Then I put the blue collars back on just for the looks.

I like my scale birds to fly scale, so I put the recommended engine in it. I don't know more than the designers who test the planes before marketing them, so I don't try to put a Ford Taurus Engine in a Ford Escort. ( If you catch my drift.) The Hanger 9 .40 Cub fly's very scale with a .40. A .52 would be perfect with floats IMHO.