Aerovee click noise

[T41pilot]

I have loud click noises coming from my Aerovee turbo that weren't there before. I did a couple of ground runs this morning to tweak my wastegate to achieve the 40 inches of manifold pressure spec. I was successful. Between that and addressing issues from my first flight, I was convinced I could make another flight this weekend. Well I had to move the prop some by hand to begin installing the cowling and noticed loud clicking noises coming from the back side of the engine. They definitely weren't there before. I thought I had previously read somewhere on here that it was a magnetron issue but I can't turn up anything on a search. The noise seems to be coming from the back side of the engine with no sign of parts contacting anything. The only thing I can spot right off is the bottom .010 magnetron gap may be about gone. I can't slip the shim between there anymore. So other than that, is there anything else that could be causing this? Something internal?

[Area 51%]

Type "clicking sound" in the Aerovee search box.

[GraemeSmith]

Type "clicking sound" in the Aerovee search box.

Or click this link:

search.php?keywords=clicking+sound

[T41pilot]

Thanks for the help Guys. Mike Smiths build log seems to have the best description of my problem. Unfortunately that means the second flight will not be happening any time soon. Good thing I kept my Ultralight. I'll be flying that instead for Saturday lunch.