well.. . after a weekend of trying to get this sorted out, I think i have given up. At 50% throttle, with some revs and idles, looks like 14 min is the max i am going to get per tank.

I have pulled the tank and checked the clunk and the seals. No leaks.
I did gain a full 2 mins by leaning out the mix. I am running 3 clicksrich from max rpm.

Any other ideas about why other get 20-25 mins and i get 14?