This motor has never been in the water. It's been sitting in a crate since 1968. Before I tried to start it I changed the impeller, lower unit oil, plugs, rebuilt carbs and changed all fuel lines and fuel pump and had to build a wiring harness. I finally Got it running but the hot light comes on after 5 minutes or so I turned it off and checked thermostat and it opens and closes but there was no signs of water in the thermostat housing. Could this be a head gasket? I dropped the lower unit to check the water pump impeller it was fine. So I'm checking everything else out and I noticed a milky oily film in the exhaust chamber is that normal? I understand some of the fuel doesn't burn off but does it look like that? Any help would be great. Thanks