I plan on replacing the water pump this weekend so I thought I would pick your brains here to see if I needed to look for anything else.<br />At the seam where the lower unit bolts up I have a slight amount of water leaking . After running in the lake I also have oil-gas build up there.Almost like exhaust residue. Not much but it is there. I checked the lower unit oil and it is good. Is this normal and should I be worried?