I did clamp down the bypass so nothing was going thru bypass when I ran it without a stat.
Im wondering if I should open that up with no stat and see what happens.
Maybe I should call a thermostat manufacturer.

had a similar problem and small bypass hole drilled into the t-stat fixed it.

Another thought, has the motor overheated? It is possible you have chunk of the impeller lodged somewhere in the cooling system. That can cause similar problems as well.

No overheat, Without a thermostat it runs 105-110 range though, so I can't see it being a impeller piece.
I think its junk new thermostats. I can see them in the pan of hot water not opening to higher temps(starts to crack at 150's). My old 140 opens sooner.

I tried cutting the spring down to see if it would open easier. It did not make a difference, Guess that wax pill in it does not care about spring pressure.