It was produced in 1988 and imported in 2002. Its definatley a 6v. I got the bulb details and info of a chap from BikeChatForum. Just going to pick it up now, it is one of those hideous Globe thingy's. Thanks for the help.
Sorry, I didn't mean to quote you . See the problem is, my bike is an import. So although the RS didnt exist over here in 1988 (at least it wasnt made) my RS is a 1988 :/ I managed to get a rear one from Halfrauds!
I've got a 1988 yamaha rs100 with no headlight bulb or rear bulb. I cant find the bulb details ANYWHERE, garages dont have a clue around Birmingham or warwickshire, I thought someone here might know the serial number. Plus I thought it was about time I joined the yamaha forum ;P thanks
Matt