My engines, Cummins 6BTA's (1230 hrs) have excessive smoke at cruise. Every "expert" that comes aboard has a different idea: fuel pump timing, turbo charger, worn rings, after cooler dirty----What say you?
:huh:
Do the engines start normally and do they smoke at idle?
Do the engines sound as they always have?
Not being able to see, hear or run the boat means you are likely not going to get anything more than additional opinions from the folks here, but maybe we can get you to the point where you try the easy stuff or make the decision to call Cummins.