I think you have me confused with someone else. I didn't replace the engines in this boat. I just bought this boat 6 weeks ago.

Meshikinquah, you are confusing me with someone else. I haven't replaced my motors; I just bought this boat 6 weeks ago...

They are CMI Gen-X headers that I'm buying from Teague. The port headers are standard swept back, but the starboard headers are custom big tubes because of the reverse stagger and will take several weeks to make. We think the starboard headers can be welded, so those will go back on while the others are being made so I can get back in the water. The new headers also do not have the bypass hoses that the old ones have and that Merc has issued a service bulletin to remove because the headers weren't getting enough water and not being cooled enough. That contributed to the cracking issues. I also installed freshwater flushes about two weeks ago and will be adding a better draining system to the new headers to make it easier to drain them after running the boat.

Lil Red is spot on. Heat cycles are what kills the headers. I got 260 hours out of my orig CMI's.Replaced them last year before I ever had a problem.Just felt it was the smart thing to do. Went with Gen X from CMI and have been perfect. Take a minute and contact Chris Morth at CMI [email protected]. Get a quick education on header maintenance and flushing procedure. Great guy and very helpful. Sold both sets of my old headers to members here without issue. just my 2 cents. Jeff

WOW,
HyFive578 I am sorry I was wrong. I was reading another post with almost the same problem but it was not a 525 (stuck valve post). I would be talking with guy you bought the boat from. I agree with FIXX this engine problem had to be showing signs with that much damage.

What are proper header flushing and maintenance procedures...How much more can there be?

If I'm not mistaken, Dana Marine sells an adapter bracket for the 525. You could then put on ANY BBC header you wanted.

Another CMI disappointment here. This is the second time that both my headers are cracked at the collector on my 05 525 package. They had approx. 200 hrs the first time and they were welded and lasted about 85 hrs. Not so sure that they can be welded this time. Still can't believe that merc and cmi don't step up and offer restitution in a joint effort. I realize that cmi gave merc what they asked for, but they should have denied the spec and said no. As far as I am concerned, they are both to blame. The fact that they have changed the spec, in my opinion is an admission of fault. Just my 02 for what it's worth.

Raytart,

I have a set of 525 headers that were welded and pressure tested sitting in my garage in case you're interested. PM me if so.

I'd like to know the same?!?!?!

Hyfive I'll keep that in mind. Thanks. Waiting to hear from "my guy"

I just undo the blue drain plugs after I flush and let the water drain out.

I can understand that with salt water but why would you do that in fresh water?

While not in use, I think having NO water in there is better than having ANY water in there. On another "525 header" thread this was discussed.

I'm pretty sure I'm replacing my CMI's with the SM's this winter. I have around 230 hrs. on a 2005 525. I figure I am pushing my luck by now.

That is the advice I had been given as well. I flush the headers for 5-10 minutes, let things cool down and then drain the water. I installed a draining system on my headers. I removed the elbows that connect the bypass hoses from the distribution rail to the tails (this is a Merc service bulletin to allow more cooling water to stay in the jackets). One on side, I installed a 3/4" to 3/8" reducing bushing which I then connected a 3/8" to -06 AN adaptor to which I connected a 3/8" hose. That hose runs into a custom made tee that's attached to the other header, to which a ball valve (see picture) is attached. The other side of the ball valve drains out into the bilge. When I'm done flushing, I open the valve and both headers drain out in seconds. [ATTACH=CONFIG]511836[/ATTACH]

You know what would be slick is an electric valve of some sort that would stay closed when the key is turned on and open to dump the water out of the drains when the key is turned off. Everything would be automatic.

Sounds good in theory but I wouldn't want the headers to drain out every time I turn the motor off... and you really shouldn't drain the headers when they're hot. It's the heat cycles that ultimately causes them to break down. I wait at least 10-15 minutes before draining them and the water comes out just warm.

Yeah, I am thinking draining the water and letting the air get to the metal is a bad deal? Isn't oxygen the real killer when it comes to rust and corrosion? I would say flushing with an anti-corrosive like salt away or maybe even filling with anti-freeze?

I'm sure there are differing opinions on this but here's my rationale and what I've been told by surveyors and pretty knowledgeable engine guys. If you boat in salt water, no matter how much you flush, there will still be residual salt in the system, it's virtually impossible to get it all out. If you happen to develop a leak that you have not detected and the headers are filled, that water is going to leak down and sit in the cylinder when the engine is idle. If it's salt water, that cylinder will rust in no time. Water always finds its way to the weakest point. It was strongly recommended to me to flish and drain headers after use for this reason. Another engine guy I know told me that he installs automatic drains as matter of practice on all headers when they come in with leaks to be welded. This same guy also recommends flushing with salt-away first and then running a second flush using a salt-away canister filled with WD-40 to coat the inside of the system and prevent the salt buildup.