Is it possible to repair an engine thermostat or is best to just replace it?
Replace it. I carry a spare but you can get the boat home running without one.
If it's causing you grief, as MB said just take it out. You may even get away with leaving it like that for a while. But it's probably not worth trying to fix. Just replace it.
remove it and take it home boil up some water and see if it opens .The motor will run fine with out it installed just a lower operating temp .But replace it as some stage
remove it and take it home boil up some water and see if it opens .The motor will run fine with out it installed just a lower operating temp .But replace it as some stage
Or soak it in Coca-Cola
Replace it.
It is highly likely that he wax inside the thermostat, which contracts or expands with the temperature change, is gone. In this case the thermostat should be open and the engine will be running on a much colder temperature - it will be flushed with cold water. If it's stuck in closed position, which is rare, replace it immediately as this will overheat the engine.
Replace ok.
Symptoms are engine is slow to warm up and at cruise just reaches operating temperature. However when above cruise temperature is high but not at a dangerous level. Once I slow to cruise or less temp drops quickly to normal.
So it would seems thermostat is stuck in a part open position - What do you think?
A new thermostat doesn't cost much and is an easy install, (even I have managed to do it, and usually I'm completely incompetent with fixing things), so just buy a new one. Just make sure to get all the air out of the cooling system after changing them.
it might be just the thermostat sticking. it is however also possible that other parts of the cooling system are not flowing completely freely.
i would replace the thermostat first and see what happens...