Inliners International Forums General Discussion Engines 250 lower thermostat housing

I agree with Larry. Pull it off and clean it up. Probably just a bad gasket. I generally do not use a gasket. Either RTV Ultra Black or Ultra Gray.
Put a even 1/16 layer on it and bolt on lightly. Let sit for 20 minutes and tighten it down. The grey is the better stuff and sets up in 5 minutes.

I do have that exact used one if needed.