One cylinder

Discussion in 'Sportster Models' started by 5284dva, Mar 25, 2009.

  1. 5284dva

    5284dva Member

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    My wife's 2005 Sportster 1200 Custom has been firing up on one cylinder lately, especially if the choke is not pulled out. Would this be a bad plug?

    Don
     
  2. Joyride

    Joyride Member

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    Check your ignition module and coil. Check for broken connections first. Then test to see if these items went bad. I've had to replace these several times. It it's bad plug, this is easy to replace.
     
  3. STEVE07

    STEVE07 Well-Known Member Staff Member Super Moderators

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    Start with pulling the plugs out of it and inspect them first,before you look into anything else.Spark plugs can tell you if you are running rich,lean,hot or oil fouling
     
  4. Bud White

    Bud White Well-Known Member Retired Moderators

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    check plugs and go from there ..check wire connections if you dont see anythiny with plugs
     
  5. hairydogboy

    hairydogboy Member

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    I had the same problem on my sportster 3 weeks ago,it was the rear cylinder spark plug,it looked fine but put a new one in and now its running sweet again.
     
  6. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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    HairyDB, good hearing from you 'cross the pond...! Likely simplist problem is fouled plug, but at the same time one of the toughest ignition problems was high resistance in one of my "aged" plug wires on one of my older bikes, back in the day.

    Since 5284dva has a 2008 XL modern EFI & more robust ignition, I would go with simplist problem/solution plug replacement/swap first. Another would be check that the ignition wires connections are clean and seated fully in the coil and boots to the spark plug, sometimes that terminal atop the plug unscrews so make sure they are tight and torqued properly using new standard HD plug (no substitues).
     
  7. 5284dva

    5284dva Member

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    Thanks everybody. I knew I could get good advice on this forum.
    Don
     
  8. bigd14

    bigd14 Member

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    hey I've got that same problem but I'm getting all kinds of fire, plug doesnt look bad or fouled what to do? anyone? :newsmile107:
     
  9. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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    Change out the plug anyway, with a brand new HD one and check under all the boot connections of the HV ignition wiring for corrosion or damage. Service manual has the resistance readings if you have a meter. Your bike being a 2000 could have long use wear on these components so check things out, if any question, just replace it, plugs and ignition wiring is inexpensive and easy find replacements.
     
  10. 5284dva

    5284dva Member

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    One more question. What is the correct gap for the 2005 Sportster 1200C spark plugs? I'm at work so I dont have my owners manual with me.

    Thanks,
    Don