Originally Posted by goboats
Well right or wrong basically I was asking what the outside temp might be on the cylinder heads . Thermostat housing is very difficult to get to in my boat. And there doest seem to be enough water out the back of the boat . Appreciate you opinion though thanks . Most marine
engines with raw water cooling will allow you to touch the cylinder. This one no way .
You can't calculate the outside temperature, it varies from engine to engine and from load to load , the water temperature should be under 85 c .
If you can touch the cylinder head the engine is definitely overcooled and that's as bad as being overheated if not worse .
What do you mean thermostat housing is verry difficult?
You can try to clean the hole system by running the engine and supply her water intake from a basket with fresh water and backing soda to clean the silancier and the lines.
If you have issues with the thermostat you should solve them and I am telling you that as a licensed marine engineer
(work in tankers)
If your thermostat is broken and the spare part is too expensive for you you can fit an Chinese one on your engine ,the process is as difficult as changing an impeller.
You can solve the issue other way and get your engine to "work" but will be for.little time and unsafe if you relay on it.