tbanzer

Is there a way to check the headers used on the 525s? I have read that they are notorious for cracking. Whats their life expectancy ? CMIs made exclusively for Merc Correct? Going to be looking at a couple 525 boats.

Dave M

Short answer, you can send them back to CMI to be checked.

Do a search on CMI 525 headers. Lots of info, this topic has been covered extensively.

thirdchildhood

iTrader: (6)

Yeah, it's all here. Do a search on cmi 525 headers and pressure testing headers. No sense rehashing it all.

James

CP Performance has a very nice set of replacment headers for the 525, not cheap but a cylinder full of water is not cheap either

tbanzer

Is there a visual way to see if the heads have been redrilled for replacement headers?

Raylar

The heads probably wont be drilled for replacement headers unless the previous owner changed the headers to a different type already.
If you need new sets, check with CMI, they have the new GenX headers set up for direct replacement for the 525 problem headers.

Best Regards,
Ray @ Raylar

tbanzer

Im boat shopping and Im interested in the 525 package. I had no Idea there was such a problem with these headers. I was looking towards the 525 over the 496 for possible whipple upgrades in the future and what I thought was a near bullet proof package with an XR 525 combo in stock form. Now Im worried about serious engine damage on top of 10k to replace a couple sets of headers.

thirdchildhood

iTrader: (6)

Is this problem really that wide spread or is it just that there are a lot of 525s out there and there are bound to be some exhaust problems?

breakitout

Good question.. wonder what failure % of the headers is roughly. 1%, 5%, 10%, 30% etc.

LAKESIDE RESTORATIONS

If my memory is correct Stainless marine also now has a set of manifolds for the Merc 525 & 700... At least I believe I saw it on the new 2011 price sheet they sent us..

Jamie / Lakeside