The serial number tag is situated over the SWIVEL BRACKET (port or starboard); or, check the INSTRUCTION PLATE, Situated in between the thumb screws above the steering tube. Thankfully, PartsVu provides a wealth of resources to help you find the Mercury outboard parts you need to keep your engine running https://yamahaoutboardmotorsgoldc39473.blogoscience.com/43304339/5-essential-elements-for-yamaha-outboards-for-sale-usa