Most American engines in the fifties ran on Nitro fuels. Europe didn't have nitro.
I see above you are running a 9-4, that is more of a prop for a .19 than a .29.
I ran 10-6 props on .35 engines and a 9-6 on my .29 engines. A wide blade Top-Flite for stunt or a Power-Prop for faster models like profile combat.
Too light of a prop will kick a lot.
Last edited by Dan Vincent; 03-24-2016 at 12:29 PM.