Logo
FULL SITE MENU

What block is me Mercury 25 Hp?

S

Ssimmons

New member
Is my 25 Hp Mercury block the Mercosil block? I'm wanting to rebuild it but not sure what block I have. My serial # is 0D293494 If it helps.
 
Serials 0G202750 and "below" (which is yours) are chrome and can NOT be rebored or honed. 0G202750 and "above" are the Mercosil bores that can be rebored to a max of 30 thou over.
 
Pretty much. Even the Mercosil blocks are a pain to do and not many shops will touch them.

And even if you could bore it/hone it, by the time you replace the pistons, rings and whatever else you could probably find another powerhead cheaper.

Just a set of rings will set you back almost 200 bucks (per piston).
 
Mercosil blocks have "Mercosil" cast on top of block and there are some earlier models/serials with Mercosil block(1994-04)The earlier models are serial# 0D278000 and up. Rings are $45 a set too...
 
You are better off with the block you have the chrome is pretty tough. Pull the pistons and see what you have a lot of times they are OK with a little cleaning.
 
M=Mercury. On the #1 cylinder, that is the top one, over on the throttle assembly side it will say either Mercosil or nothing. It is physically cast into the block if it is there.
 
Back
Top