-------------- Original message from "Mark Steitle" <msteitle@gmail.com>: --------------

Ed,
Do you really think I would admit to doing something like that?  I can see where maybe bad plug wires could do it, or cross-firing, or a bad coil or two.   Anyway,  that wasn't the problem either.

Well, I guess I'm going to have to tell you what it was before you go nuts (probably too late already). 

OK, here you go (drum roll)....

When I converted over to the Renesis CAS, I used the old style front cover which doesn't have a bracket for the CAS, so I had to fabricate a bracket.  So, what do you make a bracket out of that is a single point failure item?  You make it out of 4130 of course!  WRONG!!!!  Apparently, since 4130 is a ferrous metal, it disrupted the signal from the CAS at high rpm causing misfiring.  I fa bricated a new bracket from aluminum, and the misfiring went away and the engine runs great.  You have to admit that this is a very unusual situation to try to diagnose.  So, if anyone is planning on converting to the Renesis CAS, make the bracket out of aluminum, not 4130. 

OK, so now you know.  Go get some sleep before you hurt yourself. 

Mark

P.S.  Kelly - The gap does significantly affect the signal.  Before discovering the problem, I tried various air gaps.  I even got it to where the engine wouldn't start.  This gap is hard to control during the fabrication of the CAS bracket.  The final gap is about .020" and it works great at that setting.