Yamaha 15 LK What year is this motor?

[Steve H]

I recently purchased a small boat with a Yamaha 15 HP outboard. The info on the tag for the motor says YAMAHA 15 LK 684C L and the serial number is 326404. Can anyone tell me what year this motor is? I am looking for a manual for the outboard.
Thanks in advance.
Steve H

[boats.net]

That would be a 1985 motor.