Rear cylinder spark plug fouling

Discussion in 'Softail Models' started by kosmik, Jun 27, 2011.

  1. kosmik

    kosmik New Member

    3
    11
    0
    I have a 1993 fxstc with a cv carburetor with 45 and a 175 jetting with stock needle and the vacuum slider drilled to .125, the bike has the air box cut open for more air flow and non stock mufflers(not drag pipes)and an Andrews ev27 . The idle screw has been adjusted from 2 to 3 turns. The bike will idle with the screw all the way in. The bike keeps fouling the rear cylinder.

    Help I need to make it to Sturgis.
    Thanks
     
  2. TripleJ

    TripleJ Senior Member

    1,081
    48
    8
    Is it fouling due to oil or fuel. Considering it is just fouling one cylinder, I would check for good spark and run a compression test and see what you come up with. Also replace with new plugs and not just clean and reinstall.
     
  3. brownfoxx1

    brownfoxx1 Active Member

    262
    26
    0
    you can go one step hotter in that cyl.to see if that helps. i did with a 1974 fxe 1200. with no problem.
     
  4. kosmik

    kosmik New Member

    3
    11
    0
    I have replaced the coil. would a more powerful coil help ? could it be the wires? I guess the rear obviously runs hotter ,but I have not had this trouble utill recently.( 50000 on bike)
    Thanks.
     
  5. HDDon

    HDDon Experienced Member Contributor Retired Moderators

    5,456
    133
    196
    If you didn't change the plug wires that would be something I would do now. With 50,000mi. it would not hurt to do a leak down and compression check.
     
  6. glider

    glider Veteran Member

    25,464
    108
    44
    I agree with HDDon. You can check the resistance in the wires to be sure with a meter.
     
  7. 03ultra45385

    03ultra45385 Active Member

    146
    28
    3
    What about a valve seal gone bad, Has oil consumtion increased?
     
  8. kosmik

    kosmik New Member

    3
    11
    0
    Thanks I will check the wires and compression. The bike does not burn any oil.
    KOSMIK