I don't know what program you're running. My 180 turns the 18/6 at 10500 RPM peaked on 10% fuel on the bench. I don't let it run that lean on a plane.

But even so, 50mph is plenty for a 3D plane. Speed ain't gonna help much.


(edited by brad below)

Whoa... I just checked the HP on that load. I may be mis-remembering the RPM's on that prop/engine combo. That's over 4hp. I'll recheck...

Anywhoo... 50mph is enough.