Thanks motorman, I hope your arm is feeling better.

I actually only shimmed it .005 with a .003 and a .002 shim. Reason I shimmed is because of a measured head temp of 235 at steady state (peaked at over 315). The .003 brought it down to 200 or so, then I added the .002 to get it down to 180 or so (using 10% temps measured with uncowled engine).

I believe summer wind is right about the warped head, and that I've already ruined it, but live and learn. Pretty sure it was ruined when i blew the first glow plug cause it never ran the same after that.

It still seems that there is blowby since I can see a dark patch on the cyclinder wall in one area, and the ring that contacts that area is not shiny like the other parts of it.

I've been messing with this thing for a while, changed the ring the first time it lost compression and that seemed to help, but now its doing the same thing. so the head or another ring, but I think I've reached my limit on this one and will let hobby services handle it.

If you would like to see the plots of the thermocouple.... just let me know and I'll throw it up here or search for a thread titled "overheat or lean"

I wish I would have bought the tower .75