I am trying to find the correct serial number on my 15 hp Mariner outboard. I did find a number and went to marinshopen.se and found a close match but the middle two numbers were missing. The number on the motor is 684cs250640. I called my local dealer and they said that "sounded right" but could not find it. I need a serial number so I can obtain a title for the motor.<br />Does anybody recognize these numbers?