The serial number tag is located on 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 deal with you comply with acquire marketing messages from Yamaha Outboards. You could unsubscribe at any time. https://yamaha-outboard-motors-hi23092.blogtov.com/17389410/the-smart-trick-of-yamaha-150-gph-that-nobody-is-discussing