Does size REALLY matter?
Hi!
11lbs nearly 5kg is rather heavy and your .91 FS will not fly it with great authority...but it will fly in a scale like manner!
If you want more oomph! Get a 15cc twostroke...like MVVS 15cc engine. A 20cc (1.20 ) fourstroke will only make matters worse
( more deadweight).
Regards!
Jan K