Easy, engine had only 1hour boat was in great shape, local marine shop put in engine ,Ran fine last year I put in new impeller no water so shop put in new impeller have a strong mechanical background put 2nd hose on stat housing still getting hot earlier pulled large hose off stat still had...
1977 silverline 17ft . Wants to stay at 153 degrees @crusing speed 3000 to 4000 rpm, idel reaches 195 . Changed impeller thermostat engine only has 35 hours , took hose off stat housing only pushing 2” of water at idle, put 2nd hose on stat still when to 153 degrees . Could water circulation...
Also new boat owner, 1977 silverline with inline6 had only 1hour on engine ran last year overheating replaced impeller took off thermostat housing stat was in upside down. Still overheated