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Smitty 04-01-2014 08:55 PM

What ECU does a ...
 
a 2003 Merc 525 EFI have ??? Is it a MEFI 4 or a PCM-555 ?? Or something else ?? A friend is going to look at a boat with 525's and I have a Rinda scan tool but my connector only goes up to MEFI 4. Also what years were there problems with the CMI headers ??? Anything else to look for on the 525 motors?? It is a fresh water boat also.

Thanks,

Smitty

Griff 04-01-2014 09:08 PM

All the 525efi's have PCM-555's

Smitty 04-01-2014 09:37 PM

Thanks Griff !!!!

TWIN-SPINS 04-02-2014 03:23 AM

fuel likes to get into seapump,,,that shouldnt be there,,there are some post about it

Young Performance 04-02-2014 09:16 AM

As Griff mentioned, all 525's use a PCM 555. Mercury never used a Mefi 4.

Basically, the 05 and later engines are a little better. They have better headers, head bolts, and head gaskets. That doesn't mean that the 04 and earlier aren't any good.
Take a few minutes and read this thread. There is some good info on all of the drawbacks, issues, and things that need to be addressed with the 525's.

http://www.offshoreonly.com/forums/g...any-hours.html

Eddie


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