Any thoughts on this engine issue

Abodee,

Yup I got a piston stop to check my damper. My TDC mark is right on. But I do get a 10 degree fluctuation which leads me to figure I have a chain issue. Of course I am not experiencing the same problems. I think my issues are valve related. Especially due to the big swing on idle vacuum and even at higher RPM's. I am guessing a tight valve or two or worse burnt valves. I did have that severe pinging issue.

As far as this engine is concerned, Demon has moved the timing from 22 down to 14 and the problem follows to a greater or lesser degree. So I kind of question that the damper not displaying correct TDC. Unless it is so far off, that even at 22 degrees BTDC indicated it is really down near zero or retarded. That might explain the off idle improvement, especially if the diss is providing advance early. The standard light spring and heavy gap spring setup does give advance right at 1000 RPM. I know cuz I tested it. Of course if 22 BTDC is not enough, then one would figure the engine would not even run at 14 BTDC.

Boy this one is a real brain jerker.