2005 Fountain with 160 hours. Water in 5 out of 8 inner header pipes. Scuttlebutt has it that this is not uncommon. CMI taking any responsibility for this?

Nope, Your on your own.

Let me take a wild guess that it is the center motor. Mine leaked real bad on the center motor and ended up killing the motor.CMI "fixed" them the first time and then ran the boat for another 20 hours and then the motor took a crap. Bought new ones while motor was being rebuilt. Also bought the new supports that CMI is now making for them.

cmi will work with you, or people. there are more details to add. if you like give me a p.m and i ll respond.

I know many fellow racers that have had problems with their headers leaking. And this is on motors with very low hours (less than 50) and flushing after every race. My short term advise would be to draing your headers after every use. Long term would be to buy different headers.

Its seems to be a common failure with CMI and they will fight you not to cover them, we found the cure for the headers from rotting is drilling in drains to flush out the saltwater. wehave had few 525s and (1) 700 with CMIs

With the 525's you are stuck with "Mercury" CMI headers. These are different than CMI headers. They are Mercury spec'd, Mercury alloy and Mercury designed.

We as a distributor can't even get them. They are a Mercury part only.

We field these calls all the time. Another issue was with the lack of tail pipe support when installed in a staggered or triple engine set up. Letters were sent to manufacturers, but alot of them offered the supports as an option. In my opionio it should have standard equipment.

Call Big Blue, but don't blame CMI please.

dont expect help.
I replaced with custom stellings.
The headers, and the damage caused by them when they fail, is not covered under the mercury extended warranty

I don't have 525 headers, but have seen some around here fail already. So I just had my engine builder install header drains. They drain from the backside of the feed rail through the transom.

I know three people with 525s, two of them have had issues. Not a scientific study but just an observation. CMI/Merc did nothing to help.