Have you tried a 13-5 Zinger Wood Prop on a YS 63? or an APC 13-5 ?
And do the ACP props generaly put out more RPM for a given size? compared to a Zinger Wood prop.
From all my research... I know the YS-63 likes 11,000 RPM plus... better throttle transition... etc...
ORIGINAL: majortom-RCU
Anyway, the real test is how does it fly, and the flight of the Javelin/YS63/13x6 prop does fly very nicely.
When you fly your plane, you can try whatever prop sizes you want, which is the best way to convince yourself. My recommendation, like the others, is APC 13x6.