Take a picture of what you are talking about and post it. Your description and terminology is a little confusing.
I second this one.
I know there's a water line somewhere that apparently goes into the water jacket... does anyone know what these rubber "sleeves" are, and what could possibly be oozing out through the material? I took an intake runner off one of the cylinders and cleaned the rubber, but it still seems to leak.
Are you referring to the air intakes from the carbs to the cylinders? If so, this could be failed O-rings on the air intake runners, allowing a "fuel" leak, looking like dirty water on the top of the cylinder heads.