Ran my boat today and realized that the temp stayed cooler than normal at around 120-130 onstead of the normal 150. Was 80F outside too.
Would the thermostat be stuck open?
I have a 1991 3.0L mercruiser and on the hottest days it stays right at 150 also. But as the temp drops I sometimes see 120-130. I think that is fairly normal depending on the water temp. I have never had a problem with it.