Thankyou for your feedback, much appreciated.
Noted about the Carb. I will check this out. I noticed a slight oil leak from this Disy prior to this issue.
The Dash Temperature gage reached about 200 (3/4), then I turned it off to let it cool. Two years ago, fully recondition engine was purchased from MerCruiser and swapped over through a dealer. I will do a pressure test of the cooling system, How can I check if oil is leaking back from the exhaust manifolds or rotter out intake crossover?
Thankyou in advance.
200 is getting hot. as others mentioned redo your compression test to see if you have a variance when when you did it before. Also fix the issues that led to overheat if not done.
Pressure test of cooling system you apply air pressure to the cooling side of the engine. You need to plug off your water flow in hose from drive, and the water to exhaust manifolds/elbows. You can use pipe fittings and rig up a place to put compressed air in and put a gauge on it. Pressurize with 15 psi and it should hold indefinitely. If it leaks down use the air to figure out where it is leaking. Depending on which cooling system used this could be relatively easy (3 plugs) or require a bunch of plugs.
Its water leaking out of the exhaust not oil. Due to cracks, corrosion, or gasket seal issues water from cooling jackets can leak back and end up in the oil by leaking into cylinders and past rings while engine sits. If you have milky oil but level isnt really rising while running I would look at this.
water cross over tends to rot below the thermostat, you can jank the thermostat housing and see.
You can also get water down the carb when in storage if not properly covered. Most people usually toss out the flame arrestor cover but it is there so water doesn't end up in carb or distributor.