ORIGINAL: cllaurit
The plane is small for a .91 two stroke. I had one in the early 90's with a ST. x-61RE that truly defined ballistic.
Running small pattern props that would have a workable fit on a model like the Calypso, I never saw a substantial power difference between the G61 and the G90. But, that's just me.
Now put a larger prop on the G90 and you will see a substantial difference between it and the G61.
Ed Cregger