Gas engines - Does Prop alignment with stroke affect vibration?
To follow up:
I got rid of the H9 Cap and put the ZDZ40 in a Kangke Texas Hurricane. When I went to fire it up for the first time I was mentally preparing for the worst - I expected to see the tail group shaking itself to pieces when I opened up the throttle. I was even scoping out the 'net for a 50cc engine to replace it.
Smooth as freaking silk! - I have 11 flights on it now and am completely impressed with the difference (and with how the Texas Hurricane flies - but that's another thread). I figure the harmonics of my H9 Cap must be completely wrong for this engine, because the current setup is even better that I expected. Maybe the engine box and frame disspate the vibration more effectively or something. Wow.
KD