Cmi Headers/525 Efi Problems?
 

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.

stainless marine.......

money no object-EICKERTS!

go with the stainless marine mainifold's , you mit loose some bling but they will last a long long time . they come with a 5 year waranty i believe .
just dont run the cmi's when they leak real bad you will blow your motor and then it will realy cost ya
good luck

when my engine was on the dyno , mark highly recomends using the exhaust that is going to be used in the boat.

i have the gen 2's and was told that if i had cmi's or any tube type i would have seen more hp- but , i was looking for long term reliability.

i feel for the people who bought cmi's or have to keep dealing with issues of leaking..

those polished pipes sure do "bling up" the bilge , but seems for the added headaches that so many have been through it's not worth the hp...



that's just my look on it.......

I was told that CMI makes two types of headers , The one's that are leaking and the one's that are going to leak. :grinser010:

CMI Issues
 

Read this thread and all the posts . .

I have a set of CMIs on a small block Ford in a Donzi, brand new, with 5 hours use.

today I removed both headers and found 6 of eight tubes leaking water internally . .

the details are on Donzi.net at:

http://www.donzi.net/forums/showthre...383#post470383

This is a CMI problem. AFAIK Mercury Marine bought CMI last year, as I had to wait 11 months to get my system . . I selected CMI as no one else made anything for a SBF. At the time I was told by the dealer I dealt with that all production was focused on the 525 Mercury needs, and everything else was sidelined.
Regardless of production needs it seems that there is a major failure in quality and inspection. As a former fabricator of SS tube systems, this is NOT rocket science, but basic welding. I can see many flaws in the work, and feel that we need to take this a step further.

I will be discussing this with CMI this week, and am open to any direct discussions regarding these failures.

Please post me directly at: [email protected]

title the email with "CMI" . .

thank you,
Mario Langsten

Bow, NH

Good luck !!!!!

Mario,

I saw the pics at 5 hours those are down right scary

I have had a leaking header on each motor. THIS SUCKS!

They cost me 4 engines on my Cig with 525 efis

what years? models? all leak? or pre cool collar? only 03/04 years? new supports fix problem? stock merc version? or the cmi version is the solution?

whats the fuul story and solution?

LS, What did you do? Doug

Does anyone have pics of the suports and where can I get them?

Bought two new long blocks from Mercury & had headers repaired.
Leaked again. Rebuilt engines & bought 2 new sets of CMIs.
Should have never repaired them the 1st time.
CMI couldn't care less about my problems.

I'm getting a set repaired now from a 525 with 49 hours on it. The engine is being rebuilt now and don't want to trash it. Who would have the best price on a new set? Does stellings make a set for the merc heads? Doug

yes they do make headers for the 525's
http://www.monstermarinestore.com/pr...=1211&incat=59

What about the offerings from Hardin? didn't Young Performance just do a couple big motors using them?.................................robertjr

This is a common problem w/ the old style CMI Headers. We have probably thrown away 30 plus set because of this problem. Look to see if you have the latest updated style.
Look for a space between the outer pipe and the cylinder head flange of about 3/4". The outer pipe is welded back to the inner pipe just short of the cylinder head flange. If the outer pipe is welded stright to the cylinder flange, (it's the old style), you can throw them away.

is that the cool collar setup then?

I haven't heard this. If I remember right the outer tube is welded to the flange. =junk ? When did they go to this new style? Boat is a 2005. Thanks, Doug

so all 525 boats must be 10k cheaper

Here is my solution to the CMI leaking problems....Stellings! I decided to go with Stellings simply because I have had them on other boats without any problems. I got this current boat in April and ran it this past season with the CMI headers all the while keeping my fingers crossed and constantly draining them as a precaution. I didn't have any problems with the CMIs, but I didn't want to keep using them due to their track record.

This past fall I ordered a set of Stellings headers and tailpipes from Benfield's (Stellings dealer) to replace the CMIs. We have just started the install, but we have not finished it yet. We got all of the old stuff removed and the new headers on before it started raining, but we still need to install the new tailpipes. I'll post some pictures when it is finished.

Thanks Hot Duck, I like the stellings, but I don't think my Corsa diverters will fit. Looks great keep us posted. Doug

I have had a few questions on this topic, so I will post my thoughts here as well. I don't think that CMI makes a bad product in general. From what I understand and from what I have read I honestly think that the problem comes from the parameters and requirements that Mercury gave them for these headers. I also think that the problem is with this specific header design and not with CMI in general because they do make some nice products. I have had CMI headers on other boats (as well as Stellings) and have never had a problem with them. The CMIs on my current boat have not given me any problems, but with all of the failures reported on the 525s I wanted to change them out just to be safe.

Hot Duck you appear to have some kind of mufflers on your boat, what kind are they? Do they quiet the boat some? How big are the motors? Did they affect your speed much?
Thanks Steve

I posted early on in this thread with issues that were thought to be related to the failure of CMI headers on my Small Block Ford in a Donzi Corsican.

After a bit of work and some valuable support from the crew at CMI , and the dealer that sold these to me, Ateco Engines, we found the cause for the water I discovered in my exhaust ports and header tubes.

My engine is a built 400 HP 302 cu in Ford. These headers as built have a very large internal volume, and the water injection point was to close to the elbows at idle speed.
Another way to view this is that at idle the exhaust flow rate is so low in the large tubes to fully carry the water out to the transom . . . we added water outlet tubes inside the collector to inject the water further downstream and CMI supplied me with a set of anti reversion cones to install.

Water reversion can happen from water literally migrating back against the exhaust stream at low engine speeds by "wicking" along the tube walls. This happens when the cam overlap is too much and or the exhaust flow area is larger than needed . . or both . .

So I did not have issues with CMI, or their product, but challenges with a small block Ford in a boat application where there are only 2 manufacturers for headers world wide, and the other company doesn't count!

Now just what will I install in my twin engine SBC Magnum 27??

Mario L.

1969 Donzi Corsican
1968 Magnum 27

We appreciate the support Mario!!

It does have mufflers on it, but I don't know what brand they are because they were on the boat when I got it. I'll post a better picture of them when I get home tonight and maybe somebody can tell us where they came from.

These mufflers do make the boat substantially quieter, but they still yield a nice low rumble at idle and while moving. They basically take the "rasp" out of the exhaust noise and make it sound more like a muscle car than a boat running open headers.

For power I am running Merc 525s. As for the speed, I don't know if the mufflers hurt the top end or not because I have never run the boat without them.

Here is a video if the boat starting at the ramp.

http://media.putfile.com/Cig-39-2

You can't hear much engine noise because of the wind, but here is a short video of the boat up and running.

http://media.putfile.com/Cig-39

Will, when I sold the F-2 it went to the left coast.
I flew out to long beach to run it for him in the SCOPE poker run.
He put mufflers on it & during the run the boat ran 7 mph less.
I tried everything I knew to get more speed...... but couldn't

Robert,
I did use a couple sets of Hardin's headers(Hurricanes, I think) on some 1200efi's that I built. I could not be happier with them. I do not know if they make them for the 525, since the flange is different. If they do, I would not hesitate to use them.
Eddie

So has the problem been resolved with the newer 525's? If so what year was it changed, fixed?

Hot Duck - sharp boat!!