How do you read spark plugs?

Discussion in 'Engine, Fuel and Exhaust' started by BikeSAG, Nov 20, 2011.

  1. BikeSAG

    BikeSAG Active Member

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    Ok.....here is what I know to be correct when reading spark plugs:

    Gray (or grey) to light brown is good.
    White represents a condition that is too lean.
    Black represets a condition that is too rich.

    Attached are the plugs just changed from my 2007 Heritage with 35000+ miles. I have never run a fueler.

    I like that they look the same for each cylinder.

    Agree?? I'm interested in you opinion.
     

    Attached Files:

  2. SledDog

    SledDog Senior Member Staff Member Moderator

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    They look ok to me...
     
  3. aron50

    aron50 Member

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    Sounds like everything I ave read but I have no first hand experience.
     
  4. Hoople

    Hoople Account Removed

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    Reading plugs with a closed loop fuel injected system is almost meaningless, especially with ethanol fuels . It tells you nothing about the air/fuel ratio at WOT & steady cruise speeds which is so important. Fuel ratio's are not blends like they are with a carb. They are sharp cut off points.
     
  5. glider

    glider Veteran Member

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    Spark plug reading isn't what it use to be since the lead was removed from fuels. Most of the plugs pulled in modern day engines will be white and any color that is found is due to fuel additives and not a mixture reading. Quite often a change in fuel brands will yield a different color on the plug.
     
  6. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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    The plugs look fine, but as others have said, you can't "fine tune" fuel like the "good ol' days" on street machines using modern fuels.

    That is why there is a whole industry built around dynos and computerized telemetry type dynamic fuel metering/exhaust monitoring the GP bikes in racing circles these days.
     
  7. Jack Klarich

    Jack Klarich Expert Member

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    For every day riders I agree it is almost impossible now to read plugs unless you have sophisticated tools and know how, this may shed more light on how racers read plugs Reading Spark Plugs Correctly
     
  8. speedyron

    speedyron Active Member

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    get a dobeck TFI and see how much better your bike runs. Then you will be able to adjust fuel.