Wet exhaust water is black

[JimsCAL]

Originally Posted by casey1999

My 30 year old 3GMD always has grey/white smoke (trails from exhaust outlet for about 2 feet behind boat them disapears) and does this only after it was warmed up and I have been running it at high rpm. Engine uses no oil and oil color is good (no water mixed in). Would this mean I have a gasket or block problem or could it be somthing else. Engine starts easily and seems to run great, and does not overheat. Could the grey/white smoke just be from the water hitting the exhaust. I am in Hawaii so it is not from cold outside temperatures. I think my fuel is good (new). All filters are new.

What you describe is probably just water vapor, not smoke, since it quickly disappears. Sounds like the engine is fine from what else you say. I wouldn't worry.

[casey1999]

Originally Posted by JimsCAL

What you describe is probably just water vapor, not smoke, since it quickly disappears. Sounds like the engine is fine from what else you say. I wouldn't worry.

Thanks, I will check that off my "Things to Worry About List"

[Capt Len]

Black in the wet exaust usually means unburnt fuel ..bum injecter or low compression Or lack of of air supply ..air filter. If the engine has overheated the oil rings may be stuck and the dip stick will tell in time.