"I have been trying to figure
"I have been trying to figure out a water temp issue with my 5.7 mercruiser (Raw water cooled) At the end of last season the temp gauge seemed to stop reading, it only reads the minimum 120 and I replaced the sending unit, no help, then the gauge, still no help. I checked the thermastat and discovered that the previous owner was not running one! I installed a 170 degree stat and still no noticable temp rise. I ran a new wire from the gauge to the sending unit, still no change. I then boiled water in a pan and using the original sending unit wire and tested both sending units with the heated water and the gauge rises and reflects an accurate water temprature. While doing these test I am running the motor on a garden hose. The thermastat housing (sender is mounted in the side of it) does not seem to get warm at all, but the manifolds and risers are warm to the touch. I would think even at idle the internal engine temprature would rise enough to show a reading on the gauge. The water coming out of the exhaust ports on the outdrive is pretty warm to the touch after running for a while? Any help would be greatly appreciated!"
"I have been trying to figure out a water temp issue with my 5.7 mercruiser (Raw water cooled) At the end of last season the temp gauge seemed to stop reading, it only reads the minimum 120 and I replaced the sending unit, no help, then the gauge, still no help. I checked the thermastat and discovered that the previous owner was not running one! I installed a 170 degree stat and still no noticable temp rise. I ran a new wire from the gauge to the sending unit, still no change. I then boiled water in a pan and using the original sending unit wire and tested both sending units with the heated water and the gauge rises and reflects an accurate water temprature. While doing these test I am running the motor on a garden hose. The thermastat housing (sender is mounted in the side of it) does not seem to get warm at all, but the manifolds and risers are warm to the touch. I would think even at idle the internal engine temprature would rise enough to show a reading on the gauge. The water coming out of the exhaust ports on the outdrive is pretty warm to the touch after running for a while? Any help would be greatly appreciated!"