The serial number tag is located on the SWIVEL BRACKET (port or starboard); or, check the INSTRUCTION PLATE, Situated between the thumb screws above the steering tube. This document consists of many of Yamaha's useful trademarks. It could also include trademarks belonging to other companies. Any references to other companies https://yamahaoutboardmotorsyamah00638.dgbloggers.com/37413463/used-mercury-outboard-motor-values-no-further-a-mystery