RE: 50cc Class readings please.
54cc Poulan conversion with Ralph Cunninghams synchrospark ignition. 40:1 mix with 87octane gas.
Pro zinger 22-8 was turning around 6600-6700RPM. Thats the only prop I ever tried in that size.
Pro Zinger 20-10 was turning 7200RPM.
All this at 6000' above sea level in Denver.