[mr0077]

I'm with Bruce, I think the water pump isn't moving water, and not sure how you could (easily) check it short of pulling the pump...maybe rig up a (BIG) tub of water and drop the lower hose into it, crank it up and see if water is pumped through the motor and radiator after the T-stat opens (or run it without the t-stat). May be simpler to just pull and inspect the water pump. The neck temp being 40 degrees higher than the upper hose seems to support no flow, as they are maybe 10 degrees apart on my motor at operating temp.