Help Identifying a Mercury I bought

[Radiant]

I bought this motor and was told it was a 2.5 200 carb motor. I can't find the serial number for the motor.

Build Stamp is 4-28-94

I can't tell if the block stamp there says AA or AA with an F there, not too sure really. Just trying to figure out what I have.

Any tips on what to look at? It is sitting on a different mid so that's of no help either. Want to know if it is worth rebuilding.

[flabum1017]

should be a welch plug on top with a serial number

[Radiant]

Unfortunately it must’ve been replaced at one point. Nothing on the Welch plug

[W2F a V-King]

If it were mine, I'd pull a head and measure the ports....If your gonna build it, it's coming apart anyway.

[Merc 2.5]

Ya seems to me u have a merc replacement block and ole mother merc didnt always stamp em , can u post a pic of the block?

[Radiant]

I’ll get some pictures of the block. It could be a replacement block. I’ll measure the port height as well

[Radiant]

Took a few more pictures of the block and other parts.

[Merc 2.5]

Block sure looks like 2.5 to me
O and next guess is #1 went lean from carb or lectrics
What's the measurement across cyl?3.5?

[Merc 2.5]

And that aaf on block little weird to, usually just 2 letter

[Radiant]

I was hoping it was an FF block. You can see where it said FF, The First F is barely visible under the first A, but then it looks like someone went over it with the AA which is interesting.

And Cylinder #1 definitely looks like it went lean.

[Merc 2.5]

If it went to merc they mite had put the aa sleeves in it or sumthin , would cause for the stamp but idk, did u measure piston?

[Radiant]

If it went to merc they mite had put the aa sleeves in it or sumthin , would cause for the stamp but idk, did u measure piston?

I am going to pick up a Caliper to measure the bore and port height. What is the AA sleeve?

[Merc 2.5]

They mark blocks. Ff, aa etc, guess it's the sleeve in blocks that are different

[skeeter91]

rotate and see if the exhaust port has relief notch in it

[Kevin_From_NJ]

That is going to be a 2.0L 150. Bores look to be smaller than 3.500"
WMH-31 are 150 carbs.