Re: Lower unit, looks like oil is leaking oil.
An older crossflow engine does tend to experience failures of the powerhead base gasket. The black, oily residue is one sign of this failure. More of a messy issue. If you pull the cowling off when running, you may also detect exhaust smoke around the powerhead. This can be more problematic. The exhaust smoke can get re-ingested into the engine intake and could cause running issues. The fix is a $10 gasket and perhaps 3 hours of shop labor.
