Merc 350 Mag gurus? Help plz

[PARADOX]

Serious problem with old 350 Merc mag. Oil is milky, runs like chit.. seems like it's running on 2-3 cyl. not all 8. Can't get above 1800 RPM. sputers, rough etc. etc. Water in the cylinders, I'm sure. Gill headers. Porbobly leaked. So my problem?
Fixable? chit can the motor? If the Gill headers leak, can they be fixed?
Just about to check the compression. If the comps ar ok? what should I do?

THx
p

 

[phragle]

how long has it been sitting?? or was this a poof all at once thing??

 

[PARADOX]

For a while the starboard motor ran a bit rough. I don't think it was a sudden "poof" thing, it was getting worse, everytime I used it. This weekend, I think it just "had enough" and took a dump.

Two cylinders has no compression. One is half what it should be the rest is abut 170+-
I just call the motors as a V-5 from now on.
Doubt it's worth fixing. Anyone has a good used 454 Mag. Circa. 1994-5 ? and bravo drives?

 

[jhenrie]

Merc has the long blocks pretty cheap or pony up for the 357 mag complete not much more. Good warranty and they don't require a core so you can part out the leftovers.