Turns out it's a 1981 CB650. After I sent in the questions, I did some snooping around, and the year didn't make sense to me either. The seller changed his sign to the right year as well. I took the bike for an other ride, and it starts vibrating through the handlebars right at freeway speeds. Also, he won't come down on his price much, so I think I am going to skip on this one, even though it is in great shape.