Quick update and I feel SO stupid - almost embarrassed to post this but you folks took the time to make suggestions.....so here goes.

I read all your comments and thought I would triple check thru-hull, close off valve, strainer basket, all the way through.......used IR gun to see if really heating up and double check temp sensor......double checked antifreeze had burped...etc. Really started to think bad circulation pump per Tinkerer and BUP was going to be the answer though I bought merc parts from mich motors and they seemed fine when I installed them.

Then while I was f-ing around checking clamps on water pump and looking for leaks while the engine was idling, I noticed the pulley on the crank shaft was turning at least 4 times faster than the pulley on the water circulation pump. DUHHHHHHHH - WTF? How did I miss it - DUUUUUCHE!

Double checked belt tightness on belt from water pump to power steering and down to primary pulley and it was loose enough that it was slipping due to belt being tired. Replaced belt, tightened things up - now idles at 130 degrees.

thanks ALL for your help - amazing how one can miss something so simple.