Merc 9.9 or ???, without serial no. plate

[JALADIN]

I'm trying to identify the year & HP of my son's recently purchased used mercury engine? Is there another way to tell what the mystery motor is? Appreciate your help!!!

 

[galamb]

With a "mystery" Merc it can be a bit of work to figure out what you have.

If it's under 25 horses you can remove the (hood) and then look for a welsh plug (silver disk about the size of a quarter) on the right hand side of the powerhead (if you are standing facing the prop).

I will be just past the sparkplugs, but on the side of the waterjacket.

If you can find it, it will contain the production number which we can use to figure out the year.

Then comes "part 2".

You need to look for a casting number on the carb.

Looking at the carb throat, the carb model will be cast into the right hand side, normally in the upper half of the carb.

You are looking for a WMC-17 etc.

From that, we can determine the horsepower.

Since the 6, 8, 9.9, and 15 horse motors are identical (simply from a visual inspection point of view, with the hood off), the carb casting is the easiest way to determine horsepower - the other differences are (hidden) and would require some disassembly of the powerhead....

 

[JALADIN]

Thanks!!!

I'll take a look and see what I can find.

JAL