Cant find the year even by checking all the different serial number sites for my 15 HP Mariner outboard. I believe it is a late 70's to early 80's motor but I cant be sure. The serial number card shows 684 CS 030015. My research shows that the model is 15C(?) but this is not shown anywhere that I can see on the motor. Even the mercury dealer couldn't help me find the year. They said that it was an invalid serial number but it is in great shape and very clearly the numbers I have mentioned above. Can anyone help please! Thank you in advance.
