Yamaha Marine Outboards F4A/F4 Factory Service Manual, Page 18Get this manual
GEN INFO
IDENTIFICATION
A60001-1
IDENTIFICATION
SERIAL NUMBER The outboard motor's serial number is stamped on label which is attached to the port side of the clamp bracketNOTE: For USA model: As an anti-theft measure, special label on which the outboard motor's serial number is stamped is bonded to the port side of the clamp bracketThe label is specially treated so that peeling it off causes cranks across the serial number