Need help - fuel delivery 2002 carb

Discussion in 'General Harley Davidson Topic' started by Terry Jackson, Dec 30, 2013.

  1. Terry Jackson

    Terry Jackson Member

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    Can't find what I need in the fuel section.
    2002 Sportster just quit idling and will only run on the enrichener system. After much carb checking carb seems dry. Opening petcock and fuel does not flow out, only a few drops come out.
    Shouldn't the fuel flow freely?
    I cold blow back thru the fuel line but it seemed somewhat restricted, and still fuel wouldn't flow. I've already refilled gas tank.:small3d023:

    Any ideas?
     
  2. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

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    There should be a vacuum operated petcock on your bike if the vacuum hose from the top of the carb to the petcock is leaking or not fitted or the vacuum diaphragm in the petcock is faulty then fuel will not flow
    The vacuum pipe from the carb should have a t connector with a connection to the voes and the petcock

    Brian
     
  3. W.Bacon

    W.Bacon Member

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    You could try loosening a fuel cap to be sure there's no air lock.If not I would look at the petcock. Cheers, Bill.
     
  4. Terry Jackson

    Terry Jackson Member

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    I'll check that out. Sounds like vacuum diaphragm valve quit working or I got a vacuum leak.

    Thanks
     
  5. Bodeen

    Bodeen Well-Known Member Staff Member Moderator Contributor

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    Could be either. You can pull some suction on the hose with your mouth to see if fuel will flow from the line.
     
  6. Terry Jackson

    Terry Jackson Member

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    OK, fuel is flowing. Still only runs with enrichener on, and will not idle. There is no idle adjustment screw, only an idle speed screw.

    This happened suddenly. Ran well for years then one day it won't idle. It also acts like one cylinder is coming in and out. Does the 45* configuration cause cylinder robbing of air.fuel? The manual does not cover this very well at all.
     
  7. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

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    Using the enricher adds fuel so either you have not enough fuel without it or too much air
    Most likely cause is that the intake seals have failed allowing air to be drawn between the inlet manifold and the cylinder head
    to test for failed seals run the engine and spray some flammable fluid around the intake seals if the revs raise the seals are the problem some brake cleaner and possibly wd40 should be good for this I use a propane butane mix from a gas torch however anything that could be drawn in and change the engine revs will do

    Brian
     
  8. Bodeen

    Bodeen Well-Known Member Staff Member Moderator Contributor

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    Maybe that the low jet has a piece of trash in it. Don't take much. Maybe time to tear the carb down and clean thoroughly.
     
  9. Terry Jackson

    Terry Jackson Member

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    Yep, teardown & cleaning will be my next step.
     
  10. Jack Klarich

    Jack Klarich Expert Member

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