i use a 10x6 on a magnum 40
a 10x7 on a gms .47 or 11x5
and a 14x6 on a magnum 91 or 15x4

im a little confused at to why people run big props like a 11x7 on a .47 engine. what ever works for them i guess. or maybe its cause i run a low nitro (5%). but much above a 10x7 and it takes forever to spool up.


but for prop selection. pick what ever YOU want.
let someone get you in the prop range, like 10x7 for a .47 engine. then get a few different brands in a few different sizes and try then out.