1998 200hp Mercury EFI...

[96GlastronGuy]

Was wondering if someone could tell me what block size this is 2.4 or 2.5..And if i should put a new powerhead on or should i rebuild the one i have..(one scored piston 60psi).

 

[Dukedog]

Re: 1998 200hp Mercury EFI...

'98 is gonna be a 2.5 and well worth tha rebuild. Just be sure ta do some snoopin' ta find out what caused it. Could be a pretty long list a causes......

 

[96GlastronGuy]

Re: 1998 200hp Mercury EFI...

thanks thats helpful.. Now someone told me just to have the one hole done..Does this sound right or should a guy just put all new pistons and have all the holes done..I'm leaning towards all.. And any hints on what to look for that may have caused the problem..It was suppose to have been a new powehead like a year ago..

 

[Dukedog]

Re: 1998 200hp Mercury EFI...

Lotta pros n cons 'bout that. Yes you can do just one hole. Bunch a stuff ta consider though. How was compression on tha other five? Leak down on other five? Hours on tha motor? How well are you satisfied with tha motor when its all good? Tha MAIN thing is ta find tha guilty part/parts. If in doubt get it tested and/or cleaned (ie: injectors, ecu, sensors, tpi) or new stuff. It ain't gonna be cheap unless you make it that way, even doin' tha labor yourself.
If tha other five holes check out healthy then ya can go with tha one hole and re-ring tha other five. Tha bad hole HAS ta clean up at NO MORE tha .015. My reasoning for this is fuel delivery, not balance. Merc doesn't offer anything bigger tha .015 on tha efi motors for a reason and it ain't cause of balance. If it has ta be more than that ya need ta put a new sleeve in it n bore it standard. This is just my way of thinkin' but I'm sure there are different views 'bout this. You can just patch it for tha cheap BUT it might run 10 years or 10 minutes.

Keep us posted on what your gonna do and I'm sure you can get a lotta help here....................D

 

[j_martin]

Re: 1998 200hp Mercury EFI...

There are merc V6s running fine with a mix of pistons and even bore sleeve materials, with some nicasil, and some steel for instance. The pistons should all weigh the same. Different bore sizes doesn't seem to make any difference, just be sure the components for any one bore match , ie the right rings for the sleeve material.

Pistons are so expensive that if you aren't going to twist them into the stratosphere, and they are sound mechanically, there's no motive to redo a bore for 200 bucks if it isn't needed.

So yes, boring and sleeving one cylinder, or if it's steel sleeved just boring one oversize is a perfectly normal and sound mechanical practice.

hope it helps
John

 

[Faztbullet]

Re: 1998 200hp Mercury EFI...

Merc did make a 2.5 light and heavy piston, the light has a closed end wrist pin,lighter casting and lenght of pin is shorter.. and you cannot mix these due to weight differences. Dukedog is correct as there is no way to richen up the ECU for bigger bore that why Merc only offers a .015 but you can go .020 if needed, and yes I sell the piston Also check that head as if its a OBR reman head it has a year warranty on it. Usually the cylinders I see fail on a EFI are due to (a) faulty injector(b) faulty ECU (c)both. When you repair it , send the injectors and ECU to Tony Brucato @Brucatosvs.com and have tested and cleaned/flowed.. tell Linda and Tony that Alan sent ya!!!

 

[96GlastronGuy]

Re: 1998 200hp Mercury EFI...

Thanks guys all the info is great..Now just deciding if it's something i wanna try and tackle myself..Might make it my winter project..But will let you know the results when i decide or finish..Thanks again all of you!!!

 

[Dukedog]

Re: 1998 200hp Mercury EFI...

From tha look at tha weather up there. Being a "winter" project, you can start anytime now

Don't know how you guys do it............................