As it turns out, my problem was the ignition. My minute adjustments were all within range and after flying it Sunday temps were normal too.
Keith told me today that some C&H ignitions built after Sept. 02 were suspect. The engine was very hard to start, even with a geared Miller on 24v. We checked the plugs and spark was weak even with proper gaps.
I did baffle the cowling and it looks good. Cylinder head temps were within 10 degrees of one another.
If I get more than 4 min. per flight I'll report back on the plug color.

Thanks,
Chris