Suspected OM 40A outboard

[strega51]

Need some assistance in identifying an outboard I picked up. It was told to me that it is an military OMC 40hp. No ID plates that I can find. However, a possible serial number of 5559288 is stamped on the shaft casing. Could someone tell me the year, make model, etc of this beast?? Thanks. I am trying to do some maintenance on it but need to get a manual.

Also, what fuel/oil ratio would this take??

 

[F_R]

Re: Suspected OM 40A outboard

Isn't that kind of like asking to identify a Ford with no clues? If that is a Johnson serial number, it would be from around 1980.

How about a picture, if nothing else?