The effect of athermostat is to cause a more constant operating
temperature. But it's not going to be the temperature on the
thermostat. 175 is not too high if there are no other symptoms like
dieseling or detonation. If there are you can go to a 147 thermostat
from merc.

Eisboch wrote:
"jamesgangnc" wrote in message
oups.com...

If it had a stuck thermostat it would overheat.


That's what I figured, but then realized it could also be stuck open or
anywhere between full open or closed. Unlikely though.

My understanding of the purpose of the thermostat is to allow the engine to
warm up to normal operating temperature by preventing external water/coolant
from the manifolds, heat exchanger or radiator (in the case of an
automobile) from flowing in the block until it reaches the temperature
rating of the thermostat.

I don't think the thermostat "modulates" to maintain a specific temperature
... but maybe I am wrong?

Eisboch