270crusaders engin is not over heating replaced all parts pertaing to water flow changed heatexchanger when ru

Question

circ. pump was also replaced block was also tested somthing is making pressure to build up

Answer 1

do you have the right radiator cap?  Some times the spring in the cap rusts and weakens.  This would cause anit-freeze to spill out.  You can get a pressure test on your coolant system.  There are two sides of the cooling system on this engine.  The raw water side[water coming in the boat]  and the fresh water side[coolant, jacket water,] Hopefully you have good raw water flow. Poor raw water flow will cause an overheat.  I would flush out the coolant system and pressure test the heat exchanger cap.