The reason I didn't put in the mileage is because there's no possible way of knowing, when i was buying the bike i looked into this first....i began checking all the bikes Cb1's and super four's for mileage, all the bikes are imported from Japan, most of the clocks are changed, so if someone tells you the bike has 10,000 and the bike is ten years old there probably lying.
When i bought the bike i said to the guy there was alot of mileage on it he told me he just change the clock because the last one broke...he said if you want 5,000 on the clock i'll do it if you want 20,000 on the clock i'll do it ....so on...the same story in all the other bike shops, so after that i stoped worrying about what mileage was on the clock because it was irrelivet..
About the year Cb1's were only manufactured for 3 years between 89 and 91 so there're all about the same age, mine is 1990