Re: 3hp OMC crankcase question

[Don]

OK, so you are saying the engine runs the same with both carbs…Seems unlikely that you have two carbs with similar issues, but I guess anything is possible. You have checked the nozzle gasket and it is OK, but I would have expected opposite symptoms like others have said…
Have you tried running the engine without the air box? But again, I would have expected opposite symptoms if it was plugged up…
What year is this engine? Does it use a remote tank, does it have a fuel pump? If so, perhaps the fuel pump is leaking.
Does it look like the powerhead has been apart before, has the intake been messed with?
The only other simple thing I can think of is perhaps the exhaust is plugged up, but again I would have expected opposite symptoms.
Tell us more about the history of this engine, when was the last time it ran OK, or is it new to you and has always run this way….