Clogged Exhaust or Mixing Elbow: Clean or Replace?

[Pamlicotraveler]

We replaced ours this year for the very same concerns mentioned. The consequence of misjudging the strength could be a failure that would then flood the engine with Salt water at an inopportune point.

From Yanmar

[beej67]

Yanmar says replace every 8 years.

Ours started to clog right at the 8 year mark, like clockwork. Replaced it as per the recommendation. It really wasn't that expensive. I think the part is less than a hundred bucks.

[FarCry]

Started replacing mine on Wednesday...finally got the broken bolt out of the exhaust manifold last night. My engine is a Yanmar 2QM so not only do I get to replace the elbow but also a flange that the elbow threads onto and then bolts to the manifold. Having enjoyed spending 12 hours trying to become a pretzel to access bolts, I also am replacing all hoses and clamps that are in the vicinity of the back of the motor and hope to not find myself down there again for a looooong time.

Note to self and others...when the wife mentions a new exhaust smell in the head and companionway...listen and investigate. My exhaust elbow had a crack that was more than six inches long. Fortunately it was in a place that was letting dangerous lethal gases enter into the interior and not gallons of seawater. And we thought the headaches were from too much rum the night before, possibly not. Once the elbow was removed, it is amazing to me that the engine was able to run at all, nearly completely clogged.

[sailingdog]

FarCry—

I'm surprised you don't have a CO detector aboard your boat. If you had, you would have had warning long before it got to the headaches stage. You were risking CO poisoning... which is often FATAL. You should probably add a CO detector ASAP.

[FarCry]

SD--The list of things that are "not" on the boat is much longer than the list of things that should be on the boat. I was being sarcastic about the headaches. On the rare occaision that we motor for a few minutes to anchor, moor or pull into our slip, the the companion way is open and well ventilated. Obviously that is not a solution to the problem. Your CO2 suggestion is appreciated and I will add it to my list of things to do. However my spouse seems to be an effective detector. By replacing the exhaust elbow, hoses and clamps hopefully I will be temporarily lower my risk of inhaling toxic fumes.

[SteveInMD]

I've found CO detectors to be unreliable on boats. They seem to false alarm frequently due to humidity, or if you use any spray cleaners near them, or in certain phases of the moon . Is there a reliable sensor out there?

[sailingdog]

The domestic ones certainly are, since they're not designed for a a high humidity environment. The marine-specific ones, like the Fireboy Xintex seem to do fairly well.

Originally Posted by SteveInMD

I've found CO detectors to be unreliable on boats. They seem to false alarm frequently due to humidity, or if you use any spray cleaners near them, or in certain phases of the moon . Is there a reliable sensor out there?

[FarCry]

SD, I went to the Xintex website (How do you know all this stuff?) and looked at the Fireboy products which do seem like the appropriate sensor for the task. From their website I copied this:

Ideal for boats requiring additional CO alarm protection and for boats without a CO alarm.
The CMD-1MR-9V uses an advanced biomimetic sensor to determine CO levels. Time Weighted Average sensor technology is used to eliminate false alarms.

Install one unit in every sleeping area, galley, and confined space for adequate protection. Extremely low battery consumption – only .016 mA.

Ceiling or wall mount
Dimensions: 4.75” diameter x 1.5” depth
9V battery included
1-year limited warranty
UL 2034 Listed for Marine use.


CMD-1MR-9V
9V battery powered
Carbon Monoxide Detector

By their description I would need 4 units, galley, V-berth, head and engine compartment area to fully cover my 31' vessel. That would be about $600 worth of sensors. When compare to a life, that is a bargain but is still a substantial investment when compared to other safety equipment that is needed. Your suggestion is appreciated but my priorities move this quite a ways down on the list.

[sailingdog]

Farcry-

I do a lot of research. You might want to get a single unit for the main cabin to start with. That would only be about $100 or so...and would provide some level of protection for you and your family... while still being fairly low-cost. The one in the photo is a stand-alone unit and is only $99. It is the one I have installed on my boat.