# Just blew my lower cylinder



## cutrunner (Jun 8, 2010)

There actually is no "cylinder head" on a 25 merc.
But yes, you blowed it up.
Either it overheated and you didn't notice, or it was its time and it let loose


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## Rookiemistake (Jan 30, 2013)

Thanks , there really isnt any way of telling if its overheating.or is there?so i guess its only worth parting out.


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## cutrunner (Jun 8, 2010)

Yea you can tell but the only way to do that is tear it apart and inspect


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## cutrunner (Jun 8, 2010)

I'm not a merc guy so I'm not sure but if it has sleeves it can probably be bored out and rebuilt.
If its got chrome plasma cylinders it an anchor


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## Rookiemistake (Jan 30, 2013)

Hopefully someone will chime in.thanks


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## Dillusion (May 21, 2012)

> Hopefully someone will chime in.thanks


There is a .030 piston kit you can get, I think boats.net has it.

Be prepared to spend ~$800 +- on the rebuild unless you do it yourself though.

I would just get a brand new powerhead off ebay:

like this:

http://www.ebay.com/itm/20HP-25HP-MERCURY-MARINER-POWERHEAD-CLEAN-FRESHWATER-135-LBS-COMPRESSION-/350907095335?pt=Boat_Parts_Accessories_Gear&hash=item51b3b15927&vxp=mtr

That's a GREAT DEAL.


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## HaMm3r (Dec 11, 2006)

You could try these guys... http://www.precisioncycleinc.com/cylinder_boring/

As long as you tear it down yourself, they charge $75 per cylinder to bore it. Of course there'll be other costs for parts when you put it back together.


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## Rookiemistake (Jan 30, 2013)

Mattyvac is that one on ebay a direct fit?that would be great if all the other parts just mount the same.is this an easy swapout?


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## HaMm3r (Dec 11, 2006)

While I can't say for sure if that block would fit or not, I can say with certainty that it is not the same as the one on my 1999 Merc 25.

The guy gives the model and sn# in his listing, so you could pull up the schematics for both and compare the part #'s.


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## Dillusion (May 21, 2012)

> While I can't say for sure if that block would fit or not, I can say with certainty that it is not the same as the one on my 1999 Merc 25.
> 
> The guy gives the model and sn# in his listing, so you could pull up the schematics for both and compare the part #'s.


Your 99 is different than a 01-05 motor.

PCI is a great company and the owner is a great guy. I would recommend them but you need to tear down the block yourself anyway.

The one in the link 'should' fit. It looks exactly like the one I took off my 04 25 when I had it.


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## Rookiemistake (Jan 30, 2013)

Hey matty the guy replied and said he doesnt think it will fit.is there a certain range of years that are compatabale?


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## Dillusion (May 21, 2012)

> Hey matty the guy replied and said he doesnt think it will fit.is there a certain range of years that are compatabale?


Any 2000-2004 power head. I paid 500 for mine a few months ago.


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## Creek Runner (Sep 1, 2011)

> I'm not a merc guy so I'm not sure but if it has sleeves it can probably be bored out and rebuilt.
> If its got chrome plasma cylinders it an anchor


You can bore those now, I have a couple machine shops doing them now. 

That's not a brand new power head that is a used power head. 

There are more than 2000-2004 years that are compatible.


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## Rookiemistake (Jan 30, 2013)

The guy said that head was from an 85 mariner.not sure if it falls in the range


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## Creek Runner (Sep 1, 2011)

> The guy said that head was from an 85 mariner.not sure if it falls in the range


No a 1985 will not work.


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## HaMm3r (Dec 11, 2006)

> Your 99 is different than a 01-05 motor.


No, it's not. Same block. Check the parts diagrams.


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## Dillusion (May 21, 2012)

> > Your 99 is different than a 01-05 motor.
> 
> 
> No, it's not. Same block. Check the parts diagrams.


I was thinking of the slightly modified block of the model before yours.


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## Creek Runner (Sep 1, 2011)

> > Your 99 is different than a 01-05 motor.
> 
> 
> No, it's not. Same block. Check the parts diagrams.


Correct the 99-present 25 EL' motors are all the same.


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