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Luhrs 320 Sedan - Exhaust in cockpit

Discussion in 'Luhrs Yacht' started by Thadd, Jun 8, 2020.

  1. Thadd

    Thadd New Member

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    Feb 25, 2020
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    Location:
    NJ
    I owned this boat for a year. When I am underway, there are strong fumes in the cockpit. Making the ride in the back of the boat unpleasant. Since the carbon monoxide detector are not going off, assuming there is not a leak. Installed new exhaust hoses, all clamped appropriately. New rises and manifolds. Does anyone else have this issue? Is it a design flaw? Thanks.
  2. d_meister

    d_meister Senior Member

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    Location:
    San Diego, CA.
    Virtually all vessels have it to a greater or lesser degree, and sportfishers are often worse because of the large bluff aft facing surfaces of the house. It's commonly known as the "Station Wagon Effect". If your boat is diesel, there is less concern for CO, but on any yacht, be sure to run with the aft door closed, as the exhaust and soot can be drawn inside. If your boat is gas, CO can build up in the blood and cause ill effects even in the open air of the cockpit, so it's best that people don't stay in the cockpit for long.. The only defense is to minimize the stank with having the engines in the best tune.
    Here's a good illustration of the "Station Wagon Effect":
    https://www.youtube.com/embed/uvTz84Ypjcg
  3. Thadd

    Thadd New Member

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    Feb 25, 2020
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    1. Thank you... Will keep people up on the Flybridge and avoid it.
  4. cleanslate

    cleanslate Senior Member

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    Remove and set that CO detector at various spots on the cockpit deck and aft transom bulk head to see if it goes off. Just to see and learn. It may help you establish safe or unsafe levels.
    But yeah, what d_meister said so well, it is a common problem.
  5. Thadd

    Thadd New Member

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    Feb 25, 2020
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    Appreciate the guidance guys.. Will try different things to attempt to mitigate the issue.
  6. Boomer

    Boomer Senior Member

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    Seminole
    If it bothers you excessively, put elbows on the outside exhaust and point outwards to the side of the boat
  7. PacBlue

    PacBlue Senior Member

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    The only real fix for that situation is an underwater exhaust system. Having an enclosed Bridge only makes it worse (the station wagon effect).

    Sea Ray had an issue with gas engines and eventually had a underwater bronze leg near the transom go through the hull to discharge the exhaust underwater.

    The worst case is the buildup of carbon monoxide in the cabin spaces were some one is sleeping and unaware, this can be fatal.
  8. DOCKMASTER

    DOCKMASTER Senior Member

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    Location:
    Ketchikan, Alaska
    This is not something to take lightly. I had a friend who nearly died from this. In fact, by the time they got him off the water and to the hospital the doctor's couldn't understand why he wasn't dead based on the levels in his blood. Do a quick google search and you will find many tragic stories. I recommend you get a meter and verify what the levels are. Usually you can not tell how much is in the air. It also settles in the air so you can get an increasing build-up. Please keep yourself and your passengers safe. I would hate to hear of you having a serious health issue on your boat.
  9. d_meister

    d_meister Senior Member

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    Location:
    San Diego, CA.
    Is the boat gasoline or diesel? I researched this a bit some years ago after becoming concerned about the deaths from kids in the water due to generator exhaust. My findings were that there is significantly less danger of CO poisoning with diesel. Still is not healthy to breathe, though.
    On the subject of CO alarms, try to get dedicated units. CO accumulates at lower levels in the air column, so a combined Smoke/CO is the definition of good intentions gone wrong. I mounted a CO detector on the end of the saloon settee at the floor near the aft sliding door on a yacht, and the owner objected to the appearance of a white plastic box stuck on the wood. He was fine with it after I explained the rationale.
    The only time I had a CO detector go off was when overcharging batteries in the engine room seeped gases into the living spaces. A bonus ability of that particular CO detector is detecting explosive hydrogen gas. I wouldn't bet that they all do it, though.