RE: planes plus extra 27% w/ brison 3.2
I have a Brison 3.2 in a EF 87" Yak. It has 6 gal through it now & turns a MSC 22/8 @ 7000 rpm. It would be quite difficult to find a 50cc engine that will turn that prop any better. You already have a good, solid engine,, go with it. You'll love it.