CHange headers or not
 

Ok guys here goes

I need your help to decide what to do.
I have a 525 take out with stock headers as spec by Merc.
They seem to have a product that might leak into the engine and then bad stuff happens> I do not know for sure they have a problem but there is a whole lot of whispering going on.
The same company that made the headers for merc is making a replacement model I understand.

So
1. Do I change the headers and not worry about water entering the exhaust. Reversion
2. Run them since I tested them (no Leak yet 35 hours on the engine) but I had a stuck exhaust valve #8 cylinder to fix on the first start up.

i am not sure what I would do in your case.

Yes people are having problems. On the other hand there are a LOT of those headers out there and you ONLY hear about the nightmares.

If you have the money - change them.

Not sure about the whispering, seems more like shouting to me. Tons of threads on OSO about this issue. If you have the money I'd change them out. However I'd not be to thrilled to replace them with a model from the company who's headers failed so many.

I wouldn't change them, but I would pull them off and pressure test them. CMI has been good at repairing them.

I had an issue with my cmi headers leaking on my Cigarette.
I blew one engine because of it so I bought 2 new long blocks from Mercury & had the headers checked & repaired.
They told me they would be good to go. Well wrong.
About 20 hrs. later we got water in both engines & did more damage to the new engines.
I then had to have the new engines rebuilt & bought two new sets of CMI headers. If I would have bought the new headers in the beginning I would have saved a TON of money & aggravation. Plus I missed a few good poker runs because of it. If I bought another boat with CMI headers the 1st thing would be to replace the headers.
4 engines later I learned my lesson the hard way!

I don't understand with all the problems with CMI headers why would anyone want to keep buying them? After all the failures that are talked about and lost engines I will never use them on mine. I'd rather be down 10-15 HP with another brand than go through the problems others have experienced.

Yeah, but how long with they last?

I have heard it it both ways. Some have said just buy new ones, otherwise you are going to be chasing holes. Then I have heard others say that why would you spend all that $$ when you are getting the same thing that you already have. If I had the $$ (to just throw away) I would buy new ones. The next best thing in my opinion is to send them to CMI for them to go through them.

When 525 efi's came 1st came out the aluminum heads had a different bolt pattern than cast iron heads. CMI were hooked up with Mercury Marine to make the headers.
After a few years I think Stelling started to make that header also.

Lucky Strike,

Why did you stick with CMI and not go with Stelling or some other brand?

Yes Stelling now makes 525 headers. We have repaired numerous sets of these headers. Since your motors has such low hours take the headers and have them pressure tested. If you dont want CMI to fix and test them we'd be happy to do so for you.

Dan

Stellings or CMI ??

CMI

I agree

Stellings weren't out & no other brand would work

Now you see where I am. I pulled the headers and pressure checked them no leaks. But ............... the stelling are around 7000 a set too. CMI is cheaper and I know I get what I pay for I HOPE.
Why has the not been suits over these header? Rebuilding a 525 is NOT cheap. I guess it would be hard to prove and the warranty is short.


[url]http://www.monstermarinestore.com/

Not all CMI headers leak. Pressure test them like Animal House reccomends.

My experience from running 525EFI's in both a pleasure boat and a Race Boat (both Skaters and in salt water) I have learned that the Headers can have problems. HOWEVER, I have also learned that although the Headers may be a "weak link" there are other variables that are causing the Headers to fail. Such as: a severely overheated engine or one that is always subject to overheating will break or weaken the welds on the headers thus causing them to leak. Such as: improperly installed tailpipes that are not supported properly and shift their weight to the headers, thus causing cracks. Also, just constant vibration from trailering long distances with the weight of the tailpipes on the headers can cause damage to them. People that use the tailpipes to step on to get in and out of the engine compartment putting 200 extra lbs of weight on the tailpipes again can cause problems.

My recommendation is to keep them and have them pressure tested a second time using air pressure. The fact that you already had a sticky valve is a typical sign of leaking headers. Check your tailpipes and make sure they are supported properly and will basically stay in place if they were disconnected from the headers. That should solve the problems.

You guys are great.......... Thanks but I chickened out and bought a new set of Stellings. I had them tested with Both Air and H2o no leaks but I am a suspenders and belt sort of guy and Murphy is my friend (why ask for it).

correct me if i am wrong, but I thought the 525 issue with CMI headers where Mercurys specs and not CMI. Knock on wood I have had good luck with my elbow tops. T