Merc outboard serial number question

[racerone]

Motor needs to be taken apart.

 

[Faztbullet]

1)..you cannot see ports with a bore scope
2).. pistons do not have power port in the side of them as you would see it in the pic posted..so 115
3).. you can put ported pistons in a non ported block but you will not see any difference in operation
4).. piston rice looks more like it ate a wrist pin bearing
5)..You cannot tell if block is good till it is disassembled

 

[Pchrispy5]

Found an entire kit online. Hopefully I can get to it before it’s gone. Right around 1k. Full block rebuild kit with pistons, rings, gaskets, bearings, needle bearings, etc. and it comes with the newer part number power port pistons. Be fun now that I know what I’m doing off my other outboard.
And you can tell if it has power ports from the top of the pistons. There will be the ramp on the outer lip of the intake side surface of the piston. Clearly visible in any pics that show the power port pistons loose. The block ports are what you can’t see without power port pistons. However after searching further, according to perfprotech.com the block (at least its current succession version) was exclusive to 150 and 140hp outboards, including the 1500XS. I’ll verify the block though when I crack it open for repairs.

 

[Pchrispy5]

Still curious about the block stamp. Only ones I’ve seen any reference to is the j block, and then one forum page that talked about a circled ‘C’ stamp block (didn’t really read into this one as it wasn’t what I was looking for). Otherwise everything else was later blocks with the double letter stamps. Cant find anything for the single ‘X’ stamp next to the part number. (Red circle). And then was curious on what the blue circle is a casting of. I know it’s raised so it was a cast mark.