A word to the wise about exhaust risers

[endeavour55]

My boat is 18 years old. last weekend on my way to block island, instant smoke and steam. Got the port engine shut down, cleared the smoke and started diagnosing the problem. I found a sheared exhaust bend. The exhaust bend and the mixing elbow look like stainless steel, But they are not.
the 240 hp diesel ingested salt water, and froze up. So far I have cleared the water and changed oil, and turned over by starter. no obvious sounds of clunk. going to do a compression test this weekend. fingers crossed.
Moral of the story, I was going to change the bend and the mixing elbow a couple of years ago, Wish I had. The manufacture suggested schedule is there for a reason.

[wingless]

Welcome to the forum.

Good luck w/ your engine.

The OEM raw water cooled exhaust components on my boat would last for 3-5 years before requiring replacement.

These were designed w/ no way to drain (retaining salt water 24/7/365) and no way to flush.

The exhaust required annual disassembly for internal inspection and hopeful determination that the corrosion will permit continued usage.

At my last replacement I had waaay more than enough and redesigned the exhaust using OEM components to now permitting draining after usage, followed by fresh water flush, soapy water flush, Salt Away flush, then draining bone dry, ready for the next usage.

My last annual disassembly, for internal raw water passage inspection, I discovered that the parts still look brand new, after four years of usage. At this point I would be attempting to justify the corrosion would permit continued usage.

My expectation is that my redesigned exhaust system will now last the life of the boat.

[coopec43]

Well I certainly hope I don't have your problem. I have installed a Vetus waterlock and a Vetus gooseneck which are made of synthetic materials so they shouldn't corrode. (I will install an exhaust alarm)

AND I took this guy's advice on wet exhaust design because I think he is an expert and I have complete confidence in him.

https://www.sbmar.com/articles/desig...xhaust-system/