I bought a 1967 Evinrude 18hp motor off of ebay yesterday. I also have a 1965 Evinrude 18hp. My problem is after I ran the motor in a barrel I noticed what appeared to be a carmel colored sludge coming out of a hole just below the cavitation plate. I initialy thought it was the lower unit gear lube, But when I checked it the gear lube looked fine. The hole is located between the fill and drain plugs toward the front of the foot and is smaller than the other holes. I mention I have a 1965 18hp because my other motor does not have this hole. Does anyone know what this hole is and if it should be there or should I plug it up? Thanks