Mercury 2004 225 efi water in port cylinders

[jdski2003]

Noticed port plugs fouled with a greenish residue..probably water...cleaned plugs several times, they keep fouling..starboard side seems ok, engine runs. Would a head gasket cause this on all three cylinders? If so, how difficult is replacing a head gasket? thx all...

 

[galamb]

Yes - if you are fairly certain it's water I would replace the head gasket. At worst, you have a new gasket which is relatively cheap and only takes a few minutes to install.

 

[jdski2003]

Thx, yep it's water...I'll give it a try...like you said, can't hurt......