The serial number tag is found on the SWIVEL BRACKET (port or starboard); or, check the INSTRUCTION PLATE, Found amongst the thumb screws above the steering tube. By moving into your email deal with you conform to acquire marketing messages from Yamaha Outboards. Chances are you'll unsubscribe at any time. https://caidenbftgr.anchor-blog.com/17203473/not-known-details-about-40-hp-outboard-motor-comparison