While I'm redoing the carbs (see prior post) I'm not sure if I should coat the inside of the tank. The tank had been cleaned out before I bought it, probably using the gravel method. I changed the gas when I bought it and the gas in the float bowl looked ok but there was a small amount of residue inside the bowl. Should I avoid coating the tank unless it's necessary or should I do it now before I have a problem and while the bike is apart? If so, What product is best?