Fuel in westerbeake exhaust

Discussion in 'Sport Yachts/Yachts' started by Michael Mirra, Oct 7, 2019.

  1. Michael Mirra

    Michael Mirra Member

    Jan 18, 2017
    Rock Hall, Md
    360 Sundancer 2002
    8.1 Horizon X 2
    I am getting quite a bit of what appears to be unburned fuel in the exhaust from my generator. I'm pretty sure its not oil. Can this be from not running it often enough? I seldom turn it on, which i know is not good. I plan to run it for a few hours this weekend and see what happens. Any ideas?
  2. RollerCoastr

    RollerCoastr Well-Known Member

    Nov 15, 2007
    Cedar Point, OH / Miami, FL / MacRay Harbor, MI
    1997 400DA
    340HP 7.4 Mercruiser Bluewaters
    Garmin 741, 742, 8212, 24HD, Intellian I2
    1999 280BR
    Twin 250HP Merc 350 Alpha Ones
    If a cylinder isn't firing you'll see a sheen on the water and usually the discharge will be cloudy. It could also be a stuck choke. The solenoid on mine is a serious wimp and must be regularly lubricated or it will stick closed/partially closed.

    If you've shutdown while under load or if the choke has stuck, it can foul a plug.
  3. Air O'Nautical

    Air O'Nautical Active Member

    Feb 5, 2008
    Stamford CT "Ponus Yacht Club"
    1995 400EC. Raymarine E80,4kw dome, Garmin 235 gps,
    2013 7.4L Mercruiser Blue water.
    Hurth straight shaft 630's,
    Westerbeke 7.0 BCG
    Years ago my WB was spitting fuel out the exhaust.
    Ran ok and still powered the whole boat.
    The plugs were horribly fouled..
  4. joeyleggz

    joeyleggz Active Member

    Jan 15, 2013
    long island
    current boat: 1997 sea ray 330 express cruiser
    twin 454's efi
    They will also do that if you run it without a load on them they are jetted to run under load
  5. Wanderer 290

    Wanderer 290 Member

    Jul 1, 2019
    01 sea ray 290 sundancer
    Twin 5.7 b3’s
    Gas or diesel? Actual fuel or black carbon / soot? What year and how many hours?
  6. Michael Mirra

    Michael Mirra Member

    Jan 18, 2017
    Rock Hall, Md
    360 Sundancer 2002
    8.1 Horizon X 2
    Its gas with 600 hours. It actually spits out both. The carbon seemed to clear up but not the fuel.
  7. hottoddie

    hottoddie Well-Known Member

    Jan 11, 2012
    Boston/Cape Cod
    1986 Sea Ray 390 EC
    Garmin 4212 Chartplotter
    Garmin 24 HD Radar
    Garmin 546s Plotter
    454 Crusaders
    As a 2002 is it carburetor or fuel injection. If carb I would suspect faulty choke. If FI I would suspect low operating temp (thermostat) or faulty temp sensor telling the FI that it's hasn't warmed up yet and telling the FI system to feed more fuel.
  8. Wanderer 290

    Wanderer 290 Member

    Jul 1, 2019
    01 sea ray 290 sundancer
    Twin 5.7 b3’s
    I have a Koehler 5e has with 700 hours and my problems started with a rpm hunting condition.
    After I pulled the generator and rebuilt the carburetor it was running perfectly in my driveway in a no load condition.
    Subsequently I reinstalled the generator and while it ran fine with no load. With load the carburetor would go to full throttle and bog pumping out large patches of carbon and some raw fuel in the exhaust with a reduction in rpm of approximately 500 from 3600 to 3100.
    I bought a new carburetor and bingo. The generator has been running perfectly since having put 50 hours on it since.
    Since the generator has a Kawasaki fd 501 engine I was able to cross the carburetor to a Kawasaki part and saved over 100$ by purchasing a carb from a local lawn mower retailer.
  9. sbw1

    sbw1 Well-Known Member

    Oct 10, 2006
    West Michigan
    This is listed in my signature
    This is listed in my signature
    IMG_4230.JPG It is probably a choke or a plug issue. As others have mentioned these units foul plugs quickly because it is hard to maintain a 75% load. As soon as the hot water heater is full of hot water and the A/C reaches its set point the load falls off and the plugs begin to foul. I used to change my plugs at the first sign of black carbon or fuel in the exhaust. This worked out to about every other year for the way we used the genny. WBs seem to have a personality of their own, and once you get the hang of them they work well.
    joeyleggz likes this.

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