Mercury Blackmax 150 Overheating

[Themanofsteel]

Mercury 150hp 1983
My engine overheats on high throttle.
The impeller is new and water is shooting out.
I replaced the poppit diaphragm.
I put 2 new thermostats in it. I tried removing stats and same thing.
What could be the issue?

Water steadily flows out of pic1 circled in red. Is that normal?

Also, my previous 2 engines, Force & Force/Mercury, water flowed out of the exhaust, pic 2, but no water flows out from there. Is that normal?

 

[Themanofsteel]

FYI I swapped out the mid-section with a 25” mid-section. I never ran it at high throttle when it had the shorter mid-sectionso I wouldn’t know if the problem was always there. I purchased the correct gasket for it.

Also, the temperature sender for the alarm is from a 120hp Mercury/Force 1998.