Vacuum Tube on Throttle Body?

Discussion in 'Engine, Fuel and Exhaust' started by PetieJ, Feb 28, 2012.

  1. PetieJ

    PetieJ Member

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    I have just been looking over the scoot and found something that has me wondering, "Whats-it?". It is located on the throttle body behind the air filter. My guess is some type of vacuum line used for testing. The problem I see is that the small rubber cap over this line is deteriorated and may not be sealing whatever it is suppose to seal. What is purpose of this line/tube?

    2003 Softail

    I have attached a pic of the line and rubber cap.
     

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    • cap.jpg
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  2. tyre

    tyre Active Member

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    I can't tell you what is 4, but I would make sure it doesn't leak with a new one.
     
  3. PetieJ

    PetieJ Member

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    I have not noticed any problems with running, which is good, but I can
    find no reference to it in the service manual.
     
  4. tyre

    tyre Active Member

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    Like with some elect plugs that go to now where./ test ports or to plug in a metering tool . This could be for a vaccume gage test.:D
     
  5. RibEye

    RibEye Junior Member Contributor

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    It has to do with some California-required fuel vapor elimination. Most of us don't have anything connected there. I think it connects to the fuel tank on California models.

    Enjoy,
    Rich P
     
  6. PetieJ

    PetieJ Member

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    Thanks RibEye. Something like fuel vapor recovery I reckon. It is now plugged no matter what it is. Figured it had some function for somebody.
     
  7. harley@16

    harley@16 Junior Member

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    I would make sure there is no vacuum on it because if it leaks it will cause a lean air-fuel ratio