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Irregular Idle Speed, Seems very random

Discussion in 'FZR250.com - Archives' started by mrp, Jun 21, 2007.

  1. mrp

    mrp New Member

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    I'll start by going through everything I have found on this great site to fix this stupid problem I have on my 89fzr 2kr
    Changed the battery
    Cleaned AND balanced the carbs
    Replaced airbox feet and prayed to god himself to come have a look so he can fix it :S

    The symptoms of my problem are an idle speed that varies from about 1000rpm to 4000rpm. I can fiddle with the idle screw as much as I want to but it doesn't act like its supposed to. If I turn the idles down it will start to drop the revs but out of NOWHERE it will just rise them back up again to 3000 or more, it's really all over the place. It's like if I have the screw set to 1000 it will fluctuate between that and 3000 when it feels like it.
    What this causes is alot of stalling at stops unless I have it set to idle ABOVE 3000 and it's fkn noisy idling at that speed let me tell you.
    I thought it would be the battery or carbs but now I think it might have something to do with the mixture, maybe its the coils or the float bowls? I'm still learning about bikes and have only been riding about a month but have learnt alot in that time and it would be so gratifying to fix this problem myself (with your help ofcourse <!-- s:) --><img src="{SMILIES_PATH}/icon_smile.gif" alt=":)" title="Smile" /><!-- s:) -->)

    So please can a well informed fzr buff gimme some help, I'm so stuck I'm dyin here <!-- s:oops: --><img src="{SMILIES_PATH}/icon_redface.gif" alt=":oops:" title="Embarassed" /><!-- s:oops: -->
     
  2. dave

    dave Well-Known Member

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    I would have to suggest looking for an air leak somewhere in the rubber manifolds area, are the carbs seated properly... Just a hunch! <!-- s:???: --><img src="{SMILIES_PATH}/icon_confused.gif" alt=":???:" title="Confused" /><!-- s:???: -->
     
  3. Mad_kat

    Mad_kat New Member

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    Failing that which it might well be...

    For those that never knew about this trick.. Autotrans fluid is the best way to find air leaks..

    Just put a small amount into the carby and it will burn White, And i mean white smoke.. you will see it coming out of the exhaust and the carby's and everything.. look for leaks.

    Failing that

    Try sync'ing your carbys so they are all the same... each carb needs to be matched or you will not get a good idle .
     
  4. mrp

    mrp New Member

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    I noticed when putting the carbs back on that the rubber seals around 2 of them was pretty worn. It had some cracks on it :S
    More investigating to do tomorow
     
  5. mrp

    mrp New Member

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    SUCCESS!
    Cleaning the pilot jets a a second time did the trick <!-- s:D --><img src="{SMILIES_PATH}/icon_biggrin.gif" alt=":D" title="Very Happy" /><!-- s:D -->
    Only problem now is it loves to flood... about 50% of the time it will flood on start and 100% if it was stalled beforehand. This problem is kinda out of my knowledge league but I'm thinking to much fuel so maybe the float lvl?

    thx for the replies dave and madkat
     
  6. dave

    dave Well-Known Member

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    Nice to hear a bit of success <!-- s:D --><img src="{SMILIES_PATH}/icon_biggrin.gif" alt=":D" title="Very Happy" /><!-- s:D -->

    If flooding at idle but runs ok at normal riding then the float needles are prob worn, out of adjustment or have some grit preventing them from shutting off properly. They can be adjusted to get the float levels at the correct height but if they are not shutting off completely then you will notice it at idle first.

    It is possible to fix worn float needles (bush remedy) by putting them in a fast electric drill and giving the tapered plug end (pointy end) a light cleanup with a very fine file and then some fine wet-n-dry paper (or similar). The needles need to have 3 or 6 sides or be circular for the drill to hold them properly though.
     
  7. drewzor

    drewzor New Member

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    can someone please post a photo or explain where these float needles are ?? I have a very similar problem and I'm starting to think this is the issue..

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