RE: [Awaiting Approval]
One other possibility is that your temps and humidity is going up during the day...as you fly. It happens to me here in Alabama. I sometimes have to richen the engine as the day gets hotter on my .72.
Bill, the fix that I tried by using epoxy in the backplate bolt holes in the crankcase seems to be holding up. It still runs fine with no indication of the bolts backing out like they were doing. I think that was what was allowing my manifold to vibrate since the condition appears to be fixed.