I realize that the knife is not a plane made for speed, and I don't want to try to make it that, but I may be buying one from a friend, and a k&b 61 is the only motor I have laying around to go on it. I will probably try to get a 13x4 prop or somthing to that effect. Has anyone attempted putting a 61 on a 40 sized 3D plane?

Thanks in advance for your help,
Kevin

The k&b .61 should be fine. I have a few retired ones and as I remember they fall between todays .61's and .46's in both power and weight. Should be a great combo.

I have a Knife with a .46FX/Tower muffler and a little more pull out would be nice.