The serial number tag is situated around the SWIVEL BRACKET (port or starboard); or, check the INSTRUCTION PLATE, located among the thumb screws above the steering tube. Fortunately, PartsVu contains a prosperity of resources that can assist you find the Mercury outboard parts you need to keep your engine running https://caidencinqv.alltdesign.com/yamaha-250-outboard-top-seal-for-lower-unit-an-overview-55769671