C M I 's
 

What is the average lifespan of CMI headers from the mercury racing factory, installed on their 500 & 525 efi's ? Have any of you guys had them start leaking internally on you ? If so ,how many hours did you run them before they leaked ,and did their failure cost you more than a replacement set .......................(ie, valves,heads ,ect. ).I've heard a few different stories ,would like to hear yours:eureka:

Plenty of failures discussed with 525efi headers. The 500efi's have different headers.

Are they just as bad ? or do they have a better track record ,I'm looking at a boat with 500 efi's and 287 hours ,was wondering how much longer I can expect to get out of them ,and will I know when to change them before anything else gets damaged from them leaking ??????????????????????:(

TRICK has an extended warranty plan if you buy from them



Just Kidding.......don't take this advice :)

500EFI headers have not had the failure rate of the 525EFI. They are pretty much a standard CMI E Top. The 525 headers were spec'd out by Merc and they had Cmi build them.

Mine in a 382 with 500EFI's lasted for about 200 hours. Then needed complete engine rebuilds due to leaks into the heads. And that was even with regular fresh-water flushing.

Oh: needed new headers and tail-pipes, too.

The original Silent-Choice lasted even fewer hours.

Salt kills!

Wow that sucks, Did you keep the boat in year round ? any signs of leakage prior to head job ????????????????????:(

my cig has 300 hrs no problems with the headers yet on my 500 efis hope i didnt just jinks myself

stellings i had zero problems with mine..

As Griff stated, the 500 uses the Elbow Top Header which is a very durable long lasting header. The 525 used a Merc specified and designed header that appears to have higher failure rate than other designs.

Providing the headers were drained and/or flushed if used in salt water, properly winterized in cold climates and had adequate water flow while running, they will last as long as any other exhaust system.

You can pressure test them and if there is an issue, they can usually be repaired.

If we can help, let us know.

Kirk
Ateco Engine and Dyno Shop

Header leaks
 

They cost me a motor . Droped a valve cracked the block. I sent both to cmi to pressure test & repair they said the starboard was junk and they would'nt warranty it . They said Mercury specs were different than there own (thinner & cheaper materals used) the port is perfect may have been replaced before. I tryed to have the best welder in the state repair it after 6 atempts he gave up. I would like to find a good starbord header only, if any one has one or wants to buy my port header and tail pieces. they are in great condition. I am putting keith ekrert on the new motor.248-933-5595 [email protected]

THats the advice I seem to be getting ,Take them off and pressure test ,otherwise I guess its an expensive crap shoot!!! Is taking them off and reinstalling a do it yourself Job, I've swapped out old mercruiser logs for Stainless Marine once ,not too difficult , and this time theres more room between motors ( one of the benefits of going bigger ) Any Advice? or Tips ?:cool-smiley-011:

525's, E-Tops etc., they're all the same, I wish they would last, they just don't...... :(

One of the competitors offers a 5 yr warranty. Will CMI and or Stelling's offer the same? :eureka:

One more pic....

On a seperate note, a friend of mine told me today that he has to replace all three sets of the headers on his triple engine 525 boat with only 240 hrs on them. :(

At least they lasted that long.

My fear would be that you can pressure test them and they check good today giving you a warm fuzzy feeling, but next week they develop a leak and take a motor out????

i cant speak for the sport tubes on the 525s but my e topps on the 500 are from 1999 i believe it was the first year of the 500 efi i have 300 hrs i live in jersey i run in salt and fresh water. im sure there a lot of stories not being told, were they all winterized properly did they pull the drain plugs on the dist. tubes after the water before the antifreeze.

no failures for e tops. new 525s lasted 40 hour and cracked in 2 places. thank god they were external

my friend is going thru issues now with his 525's
approx 50 hrs and merc started to give him a tough time, then came around and sent new parts. he still has to pay some of the labor. engine were less that a year old.
he did ask if it could happen again and in replacements were different. he did not get an answer

the boat is a late model epoxy OL. Last year...about 75 hrs ago...they had the header crack (it was repaired) on the center engine and it wiped out all of the valve springs from rust.....luckilly they didn't drop a valve. Now all three engines are being rebuilt and they should have lasted 500+ hours with regular maintenance. the boat was always properly maintained and properly winterized etc....no secrets...

It seems to me that Mercury feels these are "wear items" and need to be replaced every couple of years and the warranty program they offer isn't covering header failures. If they sell it as a package, it should be warrantied as a package IMHO. :(

Pretty much, they get to a certain point and you never know when to expect a failure....

Some people I know (very low numbers) have had them since the late 90's without any problems and others I know went thru sets like they were going out of style.

I have installed a few sets of the Sport tubes on customers boats in the last few years and even bought 2 sets for my new motors ( not yet installed in boat). Now I am having second thoughts and I am considering going with Stellings and Ebaying the CMI's.

I've had the same set of CMI E-Tops since 2001, fresh water only, no issues.

Not sure if it helps but I do drain them if the boat is going to sit for any length of time and drain while trailering.

Brian -

You will not have issues on the sport tubes. The 525 was an inferior product and they had issues.

Keep the CMI's there is no comparision.

Pantera,
These are the Mercury version of the Sport tubes not the CMI's does that make a difference.

from what i have heard some of the triple eng. setups were not supported properly causing problems on the 525's. My cmi's on my 500efi's are 2000 models, Leon did a repower on it a few years ago and i have not had any problems, i pull both sets over the winter and pressure test with air, so far no leaks, :cool-smiley-011: pulling them off in a week to check before season starts, i hope my luck holds

what about 575s?

what kind of headers and what kind of problems?

I wonder if the grade of Stainless Steel CMI is using is not as good of a grade that the others are using,being there corroding/rusting causing leaking???

That would explain why the salt water boats are failing more than fresh water

I think my Dad can answer that. He has been through the 525 headers and the CMI E-top and I think has suggested to CMI on the correct material to use, but I will double check. His shop in an aerospace one so they know what to use that will make it last.

not sure on the grade but I seen some stainless rust, Maybe the higher grade stainless might not hold up to heat or get brittle and crack?