Originally posted by scalebldr
flutter happens when a plane is in flight not sitting tied to the ground.if it is shaking with the engine running find the cause before flying.prop and spinner could be out of ballance or the prop itself is not square at the hub,loose engine mount or engine monting screws.broken mount or bulkhead,bent crankshaft.has this engine been run in a test stand to see if it vibrates there?
DaveB--all seems good re: prop and engine mounting.
Scalebldr--I think you are right, as this developed (I'm 90 % sure) after a couple of rough landings. I guess I run it on a test stand next.