Okay - now I feel stupid
I took the cowl off and gave everything a really good once over:
1. Both plugs were loose. If the DA caps didn't fit so good they would probably have fallen out! Yes I did check them but that was about 15 flights ago - my bad. They are good and tight now.
2. The plugs were too black. Not fouled but getting there... I cleaned them up and will get the needles set right this time.
3. I checked the needles - high is 1.5 low was 1.0 - so that means the high is at recommended rich starting setting and the low was getting quite lean... which means I screwed up and started with it WAY rich on the top and now I am just at factory (which might actually be the peak setting... I'll find out tomorrow.) I set the low back to factory so I know where I am starting from.
4. I opened up the cooling outlet a lot more and added a deflector to make some pressure change. The shape of the cowl itself is almost a baffle but I will make some further enhancements over the weekend to force air through the fins.
Hopefully I get it running well again tomorrow.