I've started the hunt for a go-fast again. The hulls I'm looking at are all custom builders from the west coast and many of them have bigger power in them than the Mercruiser stuff.

Many are equipped with the 525 and 600SCI that have the stainless individual tube headers. Since I'm using this boat in saltwater (but will flush after every use) I started to do a web search on the longevity of these headers in salt. What popped up was a bunch of threads back in 2010-2013 where people had headers cracking and the water back filling their engines.

So my question is, was this an isolated problem for a particular period and if so what years were affected?

Thanks, Ken

I believe sometime in 2006 they switched to a slightly better design of headers for the 525s. The main problem was Merc spec'ed out a lower quality material (I believe its 304 stainless vs 316 which is what CMI usually uses) and they didn't heat treat them like CMI does. Theres a couple other design faults in those headers that Merc spec'ed that led to cracking and leaking. I don't think any of the failures were a result of running in salt water IMO, I think it was a design failure. If you buy a boat with the later model headers and flush after each use, I don't think you'll have a problem. Or if its an earlier model, just factor that into the purchase price to buy the Stainless Marine kits or the CMI Gen X.

What boats are you looking at?

ToMorrow, Thanks for the info. We're looking at party cats like the Nordic 29, Eliminator Fun Deck and others. The plan is to travel out west and check out the used inventory and even discuss building a new one from the mold.

I'm getting too old to want to deal with problems and the headers seem like they are a potential failure mode. Since I don't need to be the fastest guy on the lake or ICW I could really care less about the power especially if it's going to bring headaches. However, if we look at used we'll need to be open to variations of engines and need to be prepared with the info.

This is a completely useless reply. If you had read my post you would have seen I'd done the searches and have turned to the experts for a specific question.

I came to a DISCUSSION FORUM to ask a valid question. (I even gave it it's own line in my post.) Discussion Forums DIE when nothing is discussed and there's no traffic to the site other than the search and leave mentality you are promoting.

If I'm off here please feel free to repot me to a Moderator and have me banned.

No need to report. I, as a mod read most everything on OSO and with responses like yours to him, I doubt you'll get another response from anyone else.

Long story short, again.
CMI spec'd a "best" header.
Mercury said they only want a "mediocre" header, basically just good enough to get through the warranty period. "Best" was too expensive.
CMI bucked, but then caved given the size of the revenue coming in from Mercury.
CMI received a bit of a black eye for a while, but most folks know the real story.
CMI makes and sells a "best" header direct to consumer. As do others.

Can't comment on lifespan, because it's a crap-shoot. Sometimes the have issues right away. Sometimes they last 15 or 20 years. A lot depends on the design of the boat, length of tailpipe, vibration, and how they are supported.

TomZ wasn't giving you a "search and leave mentality". He was giving you tips on how to find the information you are looking for, which sometimes isn't that easy. in addition, he offered his own experience.

OSO members - Beware you may get flamed for helping this guy.