Year of manufacture is irrelevant for servicing or value of a Tohatsu/Nissan outboard. The important thing is the model/serial. The 5A2 was made for several years. That series of motor was built around 2002. If you have a nostalgic curiosity about the date of manufacture, contact Nissan Marine at http://www.nissanmarine.com/contact.html and they may be able to find that serial number in their records.