RE: MVVS 91 setup
Dave,
Most who bought such engines that I sold, use an APC 14x8 props, with the original MVVS #3250 pipe, with a sizable extension (in rear-exhaust configuration).
Initial RPM with the engine new, was ~9,700, and it grew to ~10,200 after about 6-10 hours were accumulated.
Using the #3219Q carburettor added ~200 on top of that.
With the tank on C/G some kind of pump is imperative.
I believe one of the Walbro regulator diaphragm devices (Cline/Iron-Bay) would run better than a Perry.