Re: NO water spray
I would definately try with the ear muffs on and see if the water flows out in a stteady stream as yelladog mentioned.
If you used this engine in dirty/low water conditions you may have forced some dirt through the system which may have plugged the outlet. I had the same problem with my old Evinrude. I got a small piece if wire/guitar string and inserted slightlyt into the outlet and found it was placked just at the opening.
Also, I assume you replaced with a new impeller, if not I would definatly do so.
Thermostat?
Cheers.