wrote in message
ps.com...
Hi I have a 2002 19' bayliner with a merc 3.0L. The manual says that it
has a 160 degree thermostat in it but I warm up to 175 and stay there
from idle to WOT. Sometimes it creeps up to 179 but then goes back down
to 175.

Shouldn't i be running at 160 degrees with a 160 degree thermostat?


No. All it means is that the thermostat is supposed to be fully open at 160
degrees and starts closing below 160 degrees.

Your actual engine temperature above that will be determined by how
effective the rest of the cooling system is and water temperature.

Eisboch