idle mixture screw

Discussion in 'Yamaha 250cc In-Line 4's' started by Charlie1, Jan 13, 2011.

  1. Charlie1

    Charlie1 New Member

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    mates fzr is running pretty rough, just cleaned the carbies and it is bogging down and spark plugs are going black so my prediction is that its running too rich. where on the carbies is the fuel mixture screw?
     
  2. dave

    dave Well-Known Member

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    I would check the float levels and make sure the float valves are holding, as it is running rich as the idle mix won't fix that running rich problem. Also make sure he is not running Shell Ultra (or whatever their top premium fuel is called).

    Also you could also try running E10 fuel to help lean it out.
     
  3. karl

    karl New Member

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    my bikes RPM metre starts reading at 3000 rpm how do you guys get the idle rpm to 1500?
     
  4. dave

    dave Well-Known Member

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    You would need an external meter that picks up a signal via the spark leads.
     
  5. karl

    karl New Member

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    is that how you do it or do you just guess/dont worry?
     
  6. dontz125

    dontz125 Active Member

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    Actual idle speed is fairly irrelevant, so long as the bike idles nicely AND slows down when you release the grip - too high an idle will actually maintain street cruising speeds! As you can imagine, this gets very boring when trickling into the path of an on-coming truck... <!-- s:shock: --><img src="{SMILIES_PATH}/icon_eek.gif" alt=":shock:" title="Shocked" /><!-- s:shock: -->
     
  7. karl

    karl New Member

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    sweet thx guys.
     

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