The serial number tag is situated on the SWIVEL BRACKET (port or starboard); or, check the INSTRUCTION PLATE, Positioned in between the thumb screws above the steering tube. Luckily for us, PartsVu provides a wealth of resources that can assist you find the Mercury outboard parts you need to maintain https://cristiansdvsp.total-blog.com/rumored-buzz-on-honda-bf15d-outboard-motor-62172563