I believe clem is correct because mine does that to just to a less degree. By the way what year and hp is that? 50 to 1.....vro....Etec??? Troll alot, drive slow? You get the gist.I have this sludge that leaks out while my boat sits in garage between trips. I wipe it clean before going out on the lake and nothing leaks out while running and its clean when I put it in garage. Come out the next day and I have this. Any ideas?