The thermostat I took out had a tip with holes cut/slits in it that stuck out at the end that slid into the wide o ring located in the Thermostat seat.

The new one I put in did not have that tip it was cone shaped with the holes/slits cut in it. Guess it is a upgrade. The cone just rides on top of the oring, no chance on getting stuck like the tipped ones.

any way one of the seats/metal inserts/cap where the big/wide o ring fits into, has been damaged before I got the boat. The hole has been reduced by 1/4 of its original size. That head is hotter to the touch than the other.

can this metal seat/cap be replaced without taking the head off? if it can what tool could pull it out.

Also I read here if changing to these thermostats I need the new caps and o ring and spring anyways? Not sure what it is I need to order. Went to the local mech and he was confused also. BTW water flow and pressure are a little low after this.

Thanks for any help V/R Curtis