Had a random overheat alarm the other day on the water for my 150 VMAX carb. Water was coming out of the tell tale just fine and the impeller is only a couple of months old.
Pulled the thermostats out and put them in water over 165 degrees. I've attached a photo of both of them in the hot water. Does the one on the right look like it's not fully opening and could cause an overheat condition?
Just for what its worth and something to look at if you dont get this solved ... I had a overheat alarm that would only happen above 5,000 rpm in my 175 prov. Had good water pressure but I replaced impeller, both t-stats and both head sensors. Even installed a water temp gauge and it never got hot. Local mechanical convinced me to pulled the heads and it was full of scale. Not enough water flow. Never run in salt water, just local lakes @ conroe...
Just for what its worth and something to look at if you dont get this solved ... I had a overheat alarm that would only happen above 5,000 rpm in my 175 prov. Had good water pressure but I replaced impeller, both t-stats and both head sensors. Even installed a water temp gauge and it never got hot. Local mechanical convinced me to pulled the heads and it was full of scale. Not enough water flow. Never run in salt water, just local lakes @ conroe...
Yep I saw a few YouTube videos where that was what some guys needed to do. If the new thermostats don't correct the problem then I'll pull the heads and check it out.