A friend has a Mercury outboard that was given to him. The serial (freeze plug) is C208505. From what I've found, I believe it's a 1989 model. What I haven't been able to determine is what HP rating this motor is. It seems that the 6, 8, 9.9, and 15 hp all use the same parts with the exception of crankshaft and piston. Is there an easy way to determine the HP rating of this engine and a way to confirm the year model? Thanks in advance for any help anyone can offer on this.