I have a 525 efi with a leaking header ,port side .It seems i've read on here that cmi will repair them .Since it's saturday and i'm assuming they are closed ,Does anyone have an idea as to turnaround time and cost

No idea, but I too would be interested in the cost. Also the cost of having headers pressure checked.

It depends on the age of the header and if its in a place where it can be repaired.
I don't think they will do repairs on anything over 5 yrs old.

Boats an 06 ,so i guess that puts the repair thing from cmi out.I pressure checked today and even though it's leaking obviously in a tube ,it isn't where it can be seen with soapy water from either end .It's one header from a set of twins .The others look and test fine.Will CMI sell just one header?

I found a skilled local welder who did a great job for much less money/ time and no boxing/ shipping. I was able to find a couple options locally. Check around. CMI didn't mention age when I spoke with them, but said they won't fix it if they can't see it. If you just used air pressure to check, re check it with water and you might notice it easier.

CMI charges around $150. Yes, you should be able to buy just one header. If you end up needing to replace them both, check out the Hardin Marine, Hurricane Lites. I saw them in person at the Miami show and they looked pretty good.. If you want to stick with CMI, make sure you get the Gen-X..