Spark plugs...

Discussion in 'Engine, Fuel and Exhaust' started by Big Papa Jerry, Jul 29, 2009.

  1. Big Papa Jerry

    Big Papa Jerry Member

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    Okay ... I keep changing out spark plugs every three months or so. Is it running to lean? Previous owner had it dyno tuned about a year and a half ago, do I need to have it redone? I haven't changed or added anything (except for plugs:wall) Here is pic of them
     

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  2. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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    Actually the plugs look pretty good...the insulator area appears clean, maybe a little rich, but not bad. Does your bike seem to pull through all the gears with minor roll ons from 0-30mph 30-55 mph?

    What year is the bike and if full Stage I, what combo of mods and fueler are you using?
     
    Last edited: Jul 30, 2009
  3. R. Lewis

    R. Lewis Senior Member Retired Moderators

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    Why the dyno , what mods were done ,was it remapped with a dealer "canned map", what octane rating on fuel are you running , are you doing short local rides or out on the freeways, what gap are you setting the plugs at , have you checked the plug wires, any exhuast leaks,?????? IMO - it looks more on the rich side with the soot on it instead of lean .
     
    Last edited: Jul 29, 2009
  4. glider

    glider Veteran Member

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    Why are you changing the plugs so often?
     
  5. milsco12

    milsco12 Member

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    They do look a little dark.
     
  6. Big Papa Jerry

    Big Papa Jerry Member

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    The previous owner put gear drive cams, new cam plate and bearings, new oil pump and quick remove push rods, power commander III and Vance & Heinz slip on mufflers and had the bike dyno tuned at a reputable shop. He said the fuel/air ratio was 15:1

    I change the plugs due to it feels I loose power and there is a hesitation when I get on it. Most of my riding is short and usually in town 15-20 miles round trip from speeds of 0 to 45 MPH. Now I'm getting a real bad deceleration pop, had one before but not as bad as today, hopefully tomorrow will be better.

    Well time for a cold one :cheersand see what tomorrow brings.

    I'm using 91 octane fuel, plugs gap at 40, replaced plug wires with SE wires, haven't found any exhaust leaks. I didn't know if black soot was caused by being rich or lean, thats why these forums are a great place to live and learn. :)
     
    Last edited by a moderator: Jul 30, 2009
  7. glider

    glider Veteran Member

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    The plugs you posted have the carbon around the edge of the shell and is pretty much normal and found on most plugs in harleys, are they the correct number for the bike? They look like 6R12?
    The ground strap indicating heat range looks OK and the insulator is clean indicating a decent burn. Decel popping is a trait present with low restriction mufflers and not necessarily a sign of a problem.
     
  8. vaibhavcoder

    vaibhavcoder Member

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    I think the carbon around the plug will give you some trouble so clean that with sand paper and make it more clean.
    Also I think 3 month is too early to change the spark plug,just keep it clean and it will be good for 6 month or so.

    Noddy
     
  9. kemo

    kemo R.I.P

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    I ride 15000 to 20000 miles a year and only change my plugs once a year maybe.
     
  10. formike56

    formike56 Junior Member

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    Mine are 2 years old. 18,000 miles. Ride a lot around town but weekend ride 300 - 500 miles. Run between 45 - 80 mph.....