[Gpersi]

I just changed my risers on Crusader 7.4 Tiara 31 open for preventive maintenance once we put a load on it and got up to cruise. The freshwater side on the port engine would start to overheat  Then mechanic said change the raw water pump impeller's and thermostat we ran happened again the engine still started to run hot thought maybe it was low on cooling and coolant topped off. Ran the boat again with the hatch open and then observed coolant coming out the overflow and the hose going to the exhaust manifold was very hot about 187 on the heat gun. The mechanic is saying, maybe we need to have the heat exchanger sent out and checked out which I don’t have a problem doing I just don’t want to keep trying things and spending money if that’s not the case any ideas?