05 Roadking plug discoloration

Discussion in 'Engine, Fuel and Exhaust' started by ol55forever, Jul 11, 2011.

  1. ol55forever

    ol55forever Member

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    Ok I am not sure what the problem is. My front plug is fouling. I have a stage one w/doebeck TFI. It runs great but the front plug is black and has deposits the rear is dark but not fouled. Thanks for any and all help.:)
     
  2. Hoople

    Hoople Account Removed

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    If it is running great, what made you check the plugs.
    Is it drinking gas like no tomorrow. Have you check the mileage.
     
  3. ol55forever

    ol55forever Member

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    When I replaced plugs last spring the front plug was fouled and the rear was clean. I'm getting 40mpg with 2 up riding. I just checked out of curiosity. Maybe no big deal?
     
  4. Iceman24

    Iceman24 Well-Known Member

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    Maybe...bad plug wire..?? Normally they last forever, but I've had two vehicles w/bad wire(s) lately.
     
  5. glider

    glider Veteran Member

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    Have you checked the compression on the cylinders?

    What have you checked so far?

    Looking For Help ? - Harley Davidson Community
     
  6. Hoople

    Hoople Account Removed

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    Check to see if you have any Ion codes stored such as P1353, P1356, P1357, P1358 which may catch a wire/coil problem as Iceman suggested. You have to check the compression as Glider suggested. If your clean of any codes and your compression is equal and up to spec,,,your front injector could have a mechanical issue causing weeping or a slow reaction time to close making it run fatter than the rear.

    Start with a new set of plugs to get a fresh starting point and read. If there is another BIG difference between the plugs, look at the front injector. If the plugs are "close" in appearance but black, the TFI just may be set too high on the fat side.(?)
     
  7. ol55forever

    ol55forever Member

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    Ok guys, I've checked codes and come up with none, the front cyl is 150 and rear is 145. I replaced plugs and will keep an eye on them. Also I don't know if this is pertinent information but I have 34,000 miles on it. Thanks again
     
  8. glider

    glider Veteran Member

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    Just a thought here but maybe there's a possibility you have an intake leak in the rear cylinder causing that one to run lean and are the TFI settings at the recommended settings?

    Have you checked for that?
     
  9. ol55forever

    ol55forever Member

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    I did recheck and adjust the TFI settings and to me they seemed good very little or no change. I readjusted to my ear and it seemed ok. Maybe nothing to be too concerned about. You know just reading and wondering. Thanks again you guys are great!
     
  10. glider

    glider Veteran Member

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    Can you tell if the plug is oil fouled or fuel fouled?