What year is my amf harley Davidson serial number 3B 12108 JO?

To determine the year of your AMF Harley-Davidson motorcycle with the serial number 3B 12108 JO, you can refer to the first letter of the serial number. The "B" indicates that it was produced in 1971. Additionally, the numbering system for AMF Harley-Davidson motorcycles typically allows for identification of the model year based on the serial number format.