Vanguard 18hp shaking and blades not engaging

[vw-george]

I have a encore zero turn mower with a 18hp vanguard engine.
at the end of last year while it was idling the tone changed and it started rattling.
It only rattles at just over half RPM all the way to top end.
But the blades will not engage now.
Any ideas?

 

[ILENGINE]

Bad bearing in the electric pto clutch. Or the clutch holder is broken and it has spun the clutch on the shaft

 

[Rivets]

I second that motion.