I am helping a friend get an old Fairbanks Morse throttled engine running. After getting the mag redone (again) it runs pretty good. However, we have a small water leak somewhere. What are our options? Is there something we can splish splash around the inside of the water jacket or put in while it is running to seal the leak up? Or can we run oil in the water jacket and thus if it leaks a little it won"t be the end of the world. We don"t think it is comming from the head gasket, but will double check it.