Re: 1957 Evinrude Fleetwin 7.5 Water Discharge is HOT

[Don]

Is the exhaust housing hot also? Does the water discharge appear to have the normal amount of volume/spray? Any evidence of a prior overheat? I remember a similar sort of complaint about a 10hp…
Are you sure you used the correct powerhead base gasket? There are a few different style gaskets for the various years, the wrong one will bolt up, but will cause cooling issues.
I’m assuming this engine is new to you and you never ran it before servicing it, correct? It is kind of hard to advise here, but it is clear that you feel something is wrong. So, I guess I would go ahead and pull the powerhead/gearcase and check for common issues such as crushed water tube, plugged impeller housing vent, improperly sealed impeller plate. Did you use an OEM impeller or aftermarket? Once apart, you can check for the water tube restrictor and confirm that you have installed the correct base gasket….
I suppose you could have a bad head gasket, but that seems unlikely without causing the powerhead to overheat along with running issues. A bad inner exhaust cover seems unlikely for the same reasons…