CMI Headers
 

I'm on the second of two sets of CMI headers on Merc 525's that leaked badly. First set after 100 hrs, second after 170hrs. This time hydro locked a piston and damage internally.

How many others have had this problem?

Thanks,

Mark :(

Re: CMI Headers
 

Stellings has a new 525 header available.

Re: CMI Headers
 

Eventually everybody!

Re: CMI Headers
 

Sounds like you have personal experience here. I've been told to drain the headers sfter each use. This will save motor from major damage but issue of headers leaking still remains. This is my first boat with headers, is this something I will have to deal with on a regular basis?

Re: CMI Headers
 

Is you boat a staggered set up? Is the problem with the forward motor? If so you need to get the header supports. A buddies 39 Cig with 525's had cracking issues too. (forward motor)When this happens, water gets in the oil, the contaminated oil packs up the oil filter. With the oil filter packed up, the oil cooler is bypassed and oil temps go to the moon.

Re: CMI Headers
 

Thanks for the info, I had the exact thing happen to the staggered motor last spring with the exact same symptoms. I have not installed the support brackets on the staggered motors. The one that I am having problems with now is the rear motor installation which is a standard CMI header. DO you have any pics of the header supports?

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Sorry, I do not have pics. He has since sold the boat.

Re: CMI Headers
 

Are these headers flexing that much? This is the first time I've heard of problems with cmi's

Re: CMI Headers
 

There was a letter sent out to all OEM Boat Builders recommending the installation of the supports on all forward mounted engines due to the long tail pipes.

I will scan and try to post the picture and/or email you a picture of them.

If we can be of any assistance, please call us (847)623-2737

Re: CMI Headers
 

I have had personal experience. I treat my headers as if they are leaking weather they are or not. I have taps with long extensions and drain them every time i turn the engine off and fire with the taps open for a couple seconds to blow out any moisture. I have a very small bilge pump to suck the water out. Its all worth it for the bling and weight and HP. Thats on my Donzi 454 Mag. In the race boat in my signature picture we have stellings. Same deal but no builge pump cos we dont park up and have lots of starts between trailer. Jas

Re: CMI Headers
 

I've talked to a few people that do exactly what you do.It sounds like eventually these headers are going to leak. Have you ever used your drainage points to pump up the headers with air to check for leaks? I think by removing and plugging a couple of hoses it ccan be done right on the motor. I like your idea of a small second bilge pump, I'm going to check on that also. Thanks for the info!

Re: CMI Headers
 

Isn't frustrating to finally be able to afford nice boats with good looking stainless steel headers only to find out they provide your biggest headaches!!!!! HAVE YOU EVER HAD A SET OF CMI HEADERS THAT DID NOT LEAK!!!!?????

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What does CMI charge for these?

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CMI has both my sets now to see why they are leaking with only 70 hours on them. I should have an answer within the next few days.

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Is this why Trick Marine quit selling CMI I have 2 brand new sets and now I am afraid to use them. Brian

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Don't hold your breath, CMI only works 4 days a week!

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From people i've spoken to I understand the shelf life on Stellings headers isnt all that great.

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Really? Mine are 8 years old and look and perform as new with no repairs ever.

But, they aren't on the shelf. They're on motors. :D :D :D

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Is this true? You wont get 100 hrs. out of headers? Is it always the welds that fail? I would be afraid of them too at
3-5K a side. I`m staying stock on my stock Mags.

Too Old I tought you never had a boat more then 8 months muchless 8 years?

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That's true. :D :D :D

I know the history of this boat and engine package. ;)

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Screw all this,I'll stick with my big,ugly staimless marine 3's!!! By the way,my stainless inner,steel outer lightnings NEVER leaked even after 5 seasons and 300 hours and are still working on my buds boat,Smitty

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Haha, $3-5k per side? Try $6k per side for CMI Sport Tubes for 525EFI :mad:

Re: CMI Headers
 

Is this issue only with the new 525's in a staggered set up? Or all the 525's? I had the E Tops on my last motors, 525 SC's, for 7 seasons with no problems at all, they are still fine and boat was sold couple years ago. Boat spent the season in a slip and were never drained down between use. Is Merc / CMI doing anything to warranty these failures?

Re: CMI Headers
 

There are only two kinds of cmi,s. Ones that are leaking and ones that are going to leak. That said, I have never seen a set of cool collars leak but mercury wont use them.

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I was under the impression that Mercury is now using the cool collars on the latest generation 525's, am I wrong about that? Steve

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WOW....Quite a difference in opinions here ! Headers for a 496HO list at $5500 per engine one would expect reliability.

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That's a good lookin' engine room !:drink:

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If you are serious about 496 headers. give us a call. They are not $ 5,500.00. And are reliable.

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I am on my second set, side by side power less than 100 hours , CMI was reasonable about repair cost but I worry about damaging my motor. when i called cmi about repair they acted like it was not common . I'll have to keep an eye on them and hope for the best !:mad: :rolleyes:

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A buddy of mine has a 47 Lightning. All 3 sets of headers were repaired-2 twice. Then all 3 were replaced. One of the new sets came new with a pin hole in the outside tube-shot water 3 feet out of the engine compt. When CMI was called, they forced them to send back the header for repair, no new unit :rolleyes: These were 04 engines with 350 hours.

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I still think it's a great product. I just wish they would tighten up on their QC!!!:blaster:

Re: CMI Headers
 

Not yet.... on my 3rd boat and 5th set of headers. We'll see how well this new one does.

BOTH TIMES the response was, "Well, we've now fixed that problem". Great ---- how about in the front end next time guys (at 14k retail I think there's some money in there for a bit more warranty $$$$ and/or R&D.... in the front end! :( ).

Joe

Re: CMI Headers
 

....Because Ken never flushed the boat. Didn't he mention that? haha ---- LOL.

Seriously, as you know, Ken takes pristine care of his boats.... rephrase --- Ken pays very well for guys to take pristine care of his boats! :p

Good luck. I had the same problem w/ my 500's. Have them give you a deal on some sport-tubes for replacement.

Joe

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And Fred actually believed the seller!!! :D

Just kidding, Fred. Thanks again for all your help w/ my CMI issue last year. Sorry CMI wouldn't do what we wanted them to do re: the bolt pattern issue.

Again --- Thanks to the "anonymous" person that did what you did. Sorry I can't acknowledge you publically.

Joe

Re: CMI Headers
 

Joe, Would you please give me a call

Bob
518 361-6521

CMI Headers
 

The biggest problem with any header, is that the inner pipe heats up faster than the outer and the outer pipe cools faster than the inner , thus causing the welds or pipe to crack. CMI has been working on this problem for years. They finially found the solution by welding the outer pipe about 3/4" back onto the inner pipe away from the and the inner pipe directly to the mounting flange. We used to have to pressure test our headers every 20 hours, (for leaks), during our normal PM cycle because of this problem. Through hard work and testing CMI has corrected the cracking problem. Our headers are now lasting as long as our motors. CMI has also come out with a new one piece header that we have now gone to with NO problems. During our early years with CMI we threw away NO less than 30 to 40 sets of headers. Please note: I do not have any relations with CMI except as the end user of there product. We have been using CMI Headers for over 15 years on our motors. The shorten outer pipe design has been out since around 2005 or 06.

Gonna call tomm. see what they can do...just in case..to avoid future headaches..:ernaehrung004:

I've been through four sets (read as four engine re-builds) in 70 hours on my Baja. I finally gave up after the bills from last year and ordered two new pairs of Hardin Marine headers. I've heard from some local guys running them that they are zero failures, not like the CMI POS's. My advice to everyone... replace your headers NOW with something else. It is the same price as one rebuild and you will be good for many hours of happy boating.

I know this is an old thread, but I went through two 525 motors thanks to CMI. This yr I lost a CMI header to cracks.
Now a buddy has a crack on a 700 boat and when you look inside the motor its all pitted up.

Any ideas what this repair might cost him on a 700 boat. Motor runs like a champ still..