Now that I have the engine running, I did some maintenance, new plugs, cap and rotor and I also replaced the thermostat since the operating temp never went above 120deg. The guage was replaced last year (a combination tach, temp, trim) and the problem existed before. I went with an original VP thermostat and gasket. Now, the temp guage is still not going over 120. I ran the engine for about 3-4 minutes and checked the water coming out the back and it was fairly hot (could be touched and not get a burn). What's next, a new temperature sender which is on the thermostat housing?? Or something else. The water circulating pump has been changed at some point in the past as well.