Is it normal for a lycoming 360 biplane to experience a rpm range of increased vibration? I am trying to figure out if its an engine problem or harmonics. It smooth and minimal vibration except around 14-1700 rpm. Leaning has no effect, not mags, etc... I can't recall if it happened with my Pitts, but the Tiger Moth/Gypsy certainly did, but this feels abit different from what I recall.
Thanks,
larry
Thanks,
larry