trying to figure out model number for a Mercury 25XD

New to trying to use a forum; so I hope I am doing this right. Trying to rebuild a old Mercury 25XD. No model tag or serial number tag on motor mount; however I was able to locate a freeze plug with the number 662397 stamped into it. The carburetor has this number stamped into it, wmc-3
4/841 Any help in identify the model number and date of manufacture of this motor would greatly be appreciated.

The 25XD was built between 1984 and 1988. That number you found on the welsh plug, unless you are missing a digit is not a serial (missing one number).

The WMC-3 carb is a clue that it would be an earlier model (although all the carbs were interchangeable year to year, the 88 model had a WMC-11 or 12 on it which is why I say an earlier model - 84/85 would be a "best guess").

These were very good motors, worth fixing up unless it's totally toast.

For parts it would be safe to use a serial number 6593849 if you want to use any of the "on-line" look ups. During the model run nothing significant changed so parts from an 84 model would work on an 88 an vice versa all the way along the line.

Thanks for your quick help, galamb.

Really impressed how great this forum is. Thanks kimcrwbr1 for taking the time to give me some good advice.