Reply To: 1968 Johnson 40hp overheating

[Don]

Is the bypass ball and spring/plastic housing in place under the thermostat? It will overheat if those items aren’t there and working properly. The thermostat was out of this engine when you got it, so the previous owners may have been chasing an overheat issue as well. Is this a fresh or salt water engine? I’m guessing the gearcase has been off before, someone may have botched a water pump job. These engine really don’t spit much water from the upper exhaust relief, usually just a fine spray until the thermostat opens.