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Bike shoots up to very high rpm when starting

Discussion in 'XJ Technical Chat' started by Donglord, Aug 22, 2025.

  1. Donglord

    Donglord Member

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    I got my valves are FINALLY adjusted. Bike fires pretty good now. But it goes straight to 6k rpm (roughly) as soon as it fires. My idle screw is as far out as I can go. Would I need to maybe adjust my air/fuel mixture screw?
     
    Donglord, Aug 22, 2025
    #1
  2. chacal

    chacal Moderator Moderator Supporting Vendor Premium Member

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    Has a running (vacuum-gauges) synch been performed yet? Runaway engine rpm's are one of the tell-tale signs of an out-of=-ynch engine (although it could be due to other causes).
     
    Last edited: Aug 22, 2025
    chacal, Aug 22, 2025
    #2
  3. cds1984

    cds1984 Well-Known Member

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    Also, check that the butterflies are closing.
    Carb boot clamp rubbing on the actuator
    Throttle cable not sitting in the holder correctly
     
    cds1984, Aug 22, 2025
    #3
  4. Donglord

    Donglord Member

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    Alright I'm dumb. My throttle cable wasn't seated properly where it sits on the carb rack.
     
    Donglord, Aug 22, 2025
    #4
    cds1984 likes this.
  5. Donglord

    Donglord Member

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    I must've bumped it when I put the gas tank on somehow
     
    Donglord, Aug 22, 2025
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  6. chacal

    chacal Moderator Moderator Supporting Vendor Premium Member

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    It happens. Very small spaces down there.
     
    chacal, Aug 23, 2025 at 2:34 AM
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  7. Dave in Ireland

    Dave in Ireland Well-Known Member

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    Oh, don't worry, you're not the first that's ever done that.
    Not that I've ever done it myself, you understand.
    Never.
    Nope.
    Not me.
     
    Dave in Ireland, Aug 23, 2025 at 11:56 AM
    #7
    Dan Gardner likes this.
  8. cds1984

    cds1984 Well-Known Member

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    Lol me either.
     
    cds1984, Aug 23, 2025 at 12:01 PM
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