CMI Header leakage
 

Rubber hose which transfer cooling water from manifold to the tail pipe does not leak water it comes somewhere else...

What is the leak and where it can come ?

http://www.youtube.com/watch?v=3GNR0SqPm2A&feature=plcp

it looks like either the header or tailpipe has a leak,if it is leaking out,it may also be leaking in,id pull the exhaust off and pressure test it before engine damage happens.

+1
You have an internal leak in either the header , the tail or both. I had the same issue last year. I was able to tig the leak in the tail but not the header. Had to get a new set.

They crack in the internal welds.

I just had several headers and tailpipes repaired for a customer after a pressure test failure

Ok, there must be the internal leak.

Can the exhaust manifold leak inspect by taking of that rubber pipe and put air pressure to hose inlet to the manifold ?

If the clamp between the header and the tailpipe is not making proper seal it will pull water backwards and leak. I had this same issue, my headers were not leaking. I added an extra gasket in-between and fixed the problem, been running ever since.

fixx
 

its much safer to remove the header so you dont pump water in the engine..if your still using the boat when you stop and shut the engine off pull that plug at the end of the hoses that feed the header water..this way it wont leak into the engine..

That clamp leaking also, so it could be that.
first need to seal that properly.

Tailpipe are 15" long. Should the water comes out back of tailpipe.
If so its long way to come backwards just thinking..
but anyway will seal the clamp.

Sucks, seems to be a bigger problem with CMI stuff also.



John jr

Pressure tested header today, no leaks there :)

It must be header and the tailpipe rope seal..

No water should get to the rope seal joint unless its reverting or something is leaking. The water does not/should not mix with the exhaust until the very ends of the tail pipe. If the header pressure tested good, then my guess is the tail is leaking very close to the joint.

Pressure test done with air and with leak down tester.
Header keeps 20psi in without any leaking.

I have ask from CMI that If manifold and tailpipe seal leaks could that cause the water dropping out (pulling water backwards) ?

Here is answer:
Yes, because it is sucking in air at that point.

Regards,

David Rank
Sales Engineer
Custom Marine

WTF kind of answer is that .:angry-smiley-038:

Will check the tailpipe too.
but if tailpipe are ok then its pulling water backwards
to the leaking clamp.

Makes sense, the small leak would cause a higher vacuum that the standard exhaust exit, due to the increased velocity.

Most likely goes away at higher rpm.

Now I'm worried, I gotta check mine :/

The tail pipe will have to come off and be visually inspected and pressure tested. There is no way to plug the water exits inside the tail pipe without removing it.

I've seen the rope seal cause water leaks. Most of the time you'll get some water on the rear valve cover and if it's salt water you'll get a lot of salt on the rope and valve cover. This kind of leak ruined my polished valve covers years ago. Ruined the covers so bad even paint bubbled off after prepping and painting them. Good times!

I had the same problem w/ brand new sport tubes, the rope seals can somehow collect condensation simply from temp. difference mostly at idle.

Just throwing in a little advice here, the leak down tester is not an effective way to pressure test. The kind of leaks you see in a header usually don't flow enough air to move the gauge,

Best way is to pressurize with air (using the leak tester to regulate pressure is fine) then submerge in water,

Spraying the typical problem areas with soap bubble solution is not bad either.

And I do think water there from reversion is really common.