This is the same 1982 150 hp with the carb problem. Now when i run the engine ( i have no gauge) I put both hands on the heads and the starboard one gets hot to where I remove my hand. I replaced the pump, water comes out of the tell fine, cleaned out the popet valve and replaced the t-stats with the a washer and the gaskets. the hose connecting them is clear. any ideas what else it might be.?????

Thanks Tom

Did you do a pump kit or just an impeller?
There can be an issue with the water pump base gasket,(underneath) sucking air.
Is it hot at speed?
What size washers did you put in where the thermostats were?