1997 Mercosil block is toast?

[brentmiller]

I bought a 1997 25 Hp mercury on a 1544 as a duck rig. The dealership I bought it from had a hard time getting it dialed in when I first looked at it. After much fiddling with the timing and figuring that new gas would make it run good I bought it and took it home and started working on the hull and setting it up the way I wanted it. About a month later I took it to duck camp to GPS it and see how it handled. It took about thirty minutes to get it started (after realizing the primer is to be turned out and not pulled out as the dealership was doing it.) After drying the wet plugs it started and ran out super good with my father and I in the boat. After shutting it off, it was hard to start again.

I continued tinkering with it over the next few months as I had time (seafoam, plugs, battery, starter, etc.) I tried to run it many weekends at the river near home and paddled the SOB back onto the trailer EVERYTIME I unloaded it.

I had my dad take it to a cert Merc mechanic in his town and he said the block is bad and we're looking at $1100 repair on a $2500 rig. He explained that Merc lined the bores from 1994-1997 with Mercosil instead of cast and that they discontinued that design shortly thereafter.

What are my options? Back to the dealer to confirm the bad block issue and see what they're willing to do? I mean I can buy a known good running tiller for $1100.

Thanks for any input.
Brent
Arkansas

 

[emckelvy]

Re: 1997 Mercosil block is toast?

According to this site I found, Mercosil is bore-able:

http://www.boats.net/aftermarketparts/ob/ProOBCat05-45.html

Anybody know anything different?

But getting back to the motor, it had a problem from the day you got it from the dealership. I'd definitely be going back to them and if they have any integrity at all they'll offer to do something for you. Probably not reimbursement in full but somethin's better than nuttin'!

HTH & G'luck........ed

 

[Laddies]

Re: 1997 Mercosil block is toast?

25s before OG044026 were not reboreable but after that number were as ED said.

 

[CharlieB]

Re: 1997 Mercosil block is toast?

Who made the quantum leap that this engine needs new pistons?

You haven't mentioned what your compression is, or if you have checked it yet.

Slow down and start at square one.

Test compression

Test spark

Repost with your findings and lets go from there.

Hard to start could be a matter of adjustment

Take a little time to check it out in a logical manner, post your findings and we will figure this one out.

 

[brentmiller]

Re: 1997 Mercosil block is toast?

The local Mercury dealer owner and friend of the family did the work up.
Compression was off by 40 pounds cold but was better when warmed up (when it can run long enough to warm up.) Ignition is hot. Runs great when it's running.

He says the block needs to be replaced or re-sleeved. He's done a dozen or so Mercurys from this era with the same problems. E-X-P-E-N-S-I-V-E.

 

[25xs]

Mercosil is a boreable/machineable material...

Mercosil is a boreable/machineable material...

It's not a coating, it's the entire casting. High silica (quartz/sand) content in the block prevents the piston rings from wearing out the bore.

You can buy a complete block (std bore) with piston kit from ProMarine for $663.50 Part no. 9533 (Mercury Part No. 872-9533T40)
Reuse your crank and rods, ignition, flywheel etc...

 

[brentmiller]

Re: 1997 Mercosil block is toast?

yeah, that's what he quoted me. plus a little for seals.
it is what it is.

Thanks for the help,
Brent