Any how the issue is   that whilst running motor  I figured is was getting a bit hot  .....not sure , I could hold my hand against the head ..... just  . I removed the return hose from the t/stat   and noted water flow was somewhere between a drip and a dribble , but as I watched the flow increased to a good squirt   and then tapered off again . So obviously the  t/stat is working  ( I did test it ) .  What is happening is that the cold water in the  water jacket  closes t/stat  until water heats up ... t/stat opens  water flows   until the incoming  cold water hits the t/stat  which then closes and stops water flow . I could not see a t/stat bypass . 

 Is this normal ?  I expected the t/stat to  hover sorta   1/2 open  and maintain a more stable running temp . All this temp fluctuation cant be all that good for the motor 

Just to say ,   the motor was pulled apart because it was blowing real hard out the crankcase breather and spitting out oil . The only thing I found was the water pump impeller had 1  vane left ( never found the other bits )  and I suspect the thing had been cooked  but the piston looked good , rings still had a bit of spring left  , bore was good  ( less than a thou out of round  or tapered )  and  mostly could see the original cross hatching , but there was a glazed looking patch about 1/2 way down . Using a windscreen wiper cylinder hone it cleanrd up in about 15 seconds  .

 Just this friggin t/stat thing