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Cold Misfire cylinders 1-4

Discussion in 'XJ Technical Chat' started by Gauge, Sep 6, 2014.

  1. Gauge

    Gauge Member

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    Hi Guys,

    I have a 1980 650 seca (Australian Model), when you go to cold started it, cylinders 1-4 have no spark. When it warms up a little both cylinders come on line and the bike runs sweet.
    The valve clearances are in spec.
    Floats are clean and wet set within spec.
    Colour tuned and sync'd nicely.
    I have swapped the 1-4 coil over and tried 2 other coils. (same issue)
    Battery is charging and well charged.

    The issue is more annoying than a full on problem, as i said as soon as she warms up it will rev all the way to 9k and go through the rev range without an issue.
    My thoughts are one it is definitely an electrical misfire (nothing mechanical). I know this issue has been discussed before, but i struggled to find a definitive answer to this issue.

    Cheers

    Gauge
     
    Gauge, Sep 6, 2014
    #1
  2. Gauge

    Gauge Member

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    Any ideas guys?

    Cheers

    Gauge
     
    Gauge, Sep 8, 2014
    #2
  3. Polock

    Polock Well-Known Member

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    something's wrong with the enrichment circuit on 1 & 4 carb.
     
    Polock, Sep 8, 2014
    #3
  4. wizard

    wizard Active Member

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    HAVE YOU CHECKED THE PICK UP COILS / GAP ?
     
    wizard, Sep 8, 2014
    #4
  5. Gauge

    Gauge Member

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    Hi Polock,

    I have been through the carbs quite extensively, and the issue is too erratic to be a carb issue. No to mention there is no sign of spark on either 1-4 when this issue is occurring.

    Cheers

    Gauge
     
    Gauge, Sep 9, 2014
    #5
  6. Gauge

    Gauge Member

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    Hi Wizard,

    Do you happen to have the clearance spec for the pickup gap? I was thinking along the lines of insufficient voltage, due to the gap being too large.

    Thanks for the reply.

    Cheers

    Gauge
     
    Gauge, Sep 9, 2014
    #6

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