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 getting into your email tackle you conform to receive marketing messages from Yamaha Outboards. You could possibly unsubscribe at any time. https://yamaha-outboard-motors-fo39370.full-design.com/the-definitive-guide-to-anchor-light-marine-boat-79243516