RE: us 41 engine
Yea get a 1/4 scale Sopwith Pup from Balsa USA. I have my US 41 on mine and she is a real ball to fly. Lots of power if I need it and slow enough for a scale landing. I usually fly at just about half throttle and will do a fly by at about quarter throttle. A very gental flyer and loads of fun to fly. Just my $0.02 worth