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

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

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?

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.

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

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

That's a good lookin' engine room !

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

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 !

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 These were 04 engines with 350 hours.