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Thread: Sputter/hesitation at idle...hesitation low RPM

  1. #1
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    Sputter/hesitation at idle...hesitation low RPM

    I just got an XB12R 2008.
    It is not running right...see video.
    Any idea what might be wrong?
    https://www.dropbox.com/s/3ld6uyl3v5..._1883.MOV?dl=0
    jared

  2. #2
    Senior Member Cooter's Avatar
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    You have intermittent spark on one cylinder.

    Possible causes:
    1) Most common... Bad/fouled plug (Buellizm #54 Repeated cold starts without warming it up WILL do that)
    2) Bad or poorly connected plug wire
    3) Bad coil
    4) Primary wiring to the coil is compromised

    Possible repairs:
    1) Clean or replace the plugs NGK Iridium work well either DCPR8EIX or the 'colder' DCPR9EIX.
    2) Check or replace the plug wires for $22:https://st-paul-harley-davidson-buel...710051e0&_ss=r
    3) Replace the coil for $42: https://st-paul-harley-davidson-buel...6cc8acb5&_ss=r
    4) Check 12V spark signal at the coil terminals #1 and #3
    Last edited by Cooter; 09-25-2020 at 04:56 PM.

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    Senior Member Cooter's Avatar
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    Go light on the ll100 aviation fuel the octane rating is not computed using the same formula as automotive use it works out to about 114 octane and LL stands for low lead but the lead content in av fuel is several times higher than the highest amount in auto fuel from the 70’s it will kill most O2 sensors on the first tank. If you have a local airport you can get fuel at 60% unleaded super and 40% 100 octane unleaded av gas should give about 105 to 110 octane and good cleaning additives.

  5. #5
    Senior Member Cooter's Avatar
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    I didn't know that about the "LL" part of aviation gas but cvc is right. Any lead will kill your O2 Maybe a better choice is boat gas for no Ethanol?

    But any octane higher than the number recommended for the engine will be fine. It is simply a measure of "knock resistance". It's not going to blow anything up and doesn't contain more magic horsepowers. In FACT, higher octane fuel burns slower and more evenly.

    If you're just looking for the cleaning feature of good gas, just add gas cleaners. Seafoam FTW!!

    Either way please report up on this thread when you get her running again

  6. #6
    Senior Member 34nineteen's Avatar
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    Quote Originally Posted by Cooter
    3) Replace the coil for $42
    Important!!!

    If you choose to go this route, be sure to mark one of the coils with a large “x” so you don’t mix them up!!!

  7. #7
    Senior Member Cooter's Avatar
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    Like REALLY large, In fact, you should write "NO! This is the BAAAADDDD OONNNEEEE, do NOT re-install it again!!" In the largest neon paint you can find.

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    I think I am the one who Barrett might have been referring to with a bike from New Hampshire. I have a 2008 buell firebolt that was, well is running rough/coughs from time to time. Almost identical to what the original post said. Odd. However, My airbox top is missing. I assumed my bike was running too lean. I haven’t had a chance to do Everything to it that cooter suggested earlier. I’m working on getting the parts and my buelltooth is coming in Friday so I can check my codes. Never really thought to change/replace my plugs because it only has 11,000 miles in it but you all mention it like it could be common. Mine is not running as rough as this as jcombs posted video at all. It’s smooth for the most part just kind of coughs from time to time like the fuel mixture isn’t correct.

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    I am going to replace my plugs just to eliminate that issue. Barrett you mentioned a process to change them. Can you help me with this process by giving me some pointers? You mentioned possibly some certain tools?

  10. #10
    Senior Member 34nineteen's Avatar
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    Quote Originally Posted by jared View Post
    I am going to replace my plugs just to eliminate that issue. Barrett you mentioned a process to change them. Can you help me with this process by giving me some pointers? You mentioned possibly some certain tools?




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