Brian, you are my boat mechanic. Do you think it is necessary to drain the headers? If so, just at the end of the day? Talking fresh water use only.

Just had my headers checked at CMI this week, 280 hours. 05 Vintage boat, so headers are 04 from what CMI Dave told me. No issues, everything checked good. I too will be doing the bypass update. Seems when they start to run just a little hot, combined with fatigue from tailpipe alignment/weight this equals failure. Also 10 years of running they have served their purpose. Next season going to install Gen X replacements and not worry about headers for awhile. I make sure to install new impeller and housing every season and clean out exchanger. My next upgrade are some strainers.

2006 Fountain with 525's and not a hint of a problem here. Side by side engine set up, cool collar style pipes and no issues so far at 300 hrs.

100 % fresh water use here, FYI my take here over the years has been staggered set up with very long and heavy pipes without the extra support and salt use. Salt in my book is the kiss of death for most parts boat, period!!!

I have a 2004 42 with a full stagger. Original headers tested fine this fall. Luck of draw I guess

Salt a contributor. I had a staggered setup too but in my case, it was the rear engine that got taken out by the leaky headers not the forward one.

Carl, Like I posted the only problems I have seen from fresh water CMI's are cracks from stress from poor installation, tail pipe to tip alignment or unsupported stagger set up. I have yet to see a good set come from salt water. Every salt water boat I work on with SS headers weather it be CMI or Stellings have weld repairs or are leaking. I do not know the history of your CMI's before you bought them but I know your alignment is good now. As far as draining them all I can say is it wont hurt no matter what system you run. Stock cast iron Merc exhaust has caused more engine failures than any brand of headers ever will.

I never had leaks for HP500's but when rebuilding engines @ 10 years......I replaced them anyway.

I'll bet I've got the oldest on the site for what it's worth. I'm using 2 pair from 1992. Developed one very fine pinhole leak in a collector which was successfully welded.

I hate to jinx myself, but 2005 with 300 hrs and original with no issues.

Got a chance to look at the Hardin Hurricane 525 headers up close at the Miami show this week.. They look very well constructed. The outer tubes are bigger than the CMI's and the collector area is now coated with an anti-corrosion coating. Have no idea of they hold up better than the CMI's, but they looked pretty beefy.. Hopefully, it will be a long time before I need to think about this, but these are worth consideration.
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