The serial number tag is found to the SWIVEL BRACKET (port or starboard); or, check the INSTRUCTION PLATE, located in between the thumb screws above the steering tube. By moving into your email address you comply with receive marketing messages from Yamaha Outboards. Chances are you'll unsubscribe at any time. https://yamaha-outboard-motors-fo96272.yomoblog.com/43682298/new-step-by-step-map-for-yamaha-30-hp-jet-outboard