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bike wont run steady

Discussion in 'General' started by malc, Mar 30, 2017.

  1. malc

    malc Member

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    hi guys,i haven't been on for a while,weathers just breaking now in the uk.
    need some advice if anyone can help.
    my bike will not run smooth at average speed,i have upgraded to the 585 cam,thunderheart adjustable ign
    super g carb,but still very juddery when running in traffic.
    any ideas ?
    only thing I haven't changed is the coil,but ive been told that it wouldent be that.
     
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  2. RRRUFF

    RRRUFF Well-Known Member
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    Sounds like maybe a carb adjustment issue. Hard to diagnose without more info. I don't know much about the adjustable ignition though.
     
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  3. malc

    malc Member

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    Have rejeted the carb and rutuned,and going up and down in the gears it feels fine,just when I try to hold a steady speed it feels as if I'm in the wrong gear.plugs are a nice light brown colour .

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  4. malc

    malc Member

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    doesent seem to matter what revs or what gear I'm in,just wont run smooth,i have a strait through exhaust on it but I have fitted the preasure cones at the manifold.bike has always run like this even before the upgrades.
     
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  5. BWG56

    BWG56 Guru

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    What setting are you on with the TH programmable ignition? and you might wanna bump the intermediate up. but read this PDF from S&S first. I was all good except for a sneeze when cruising and bumping up the inter. straightened it out for me. But use this guide:old2:
     

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  6. BWG56

    BWG56 Guru

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    Also do did you try removing the auxiliary bowl vent?
     
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  7. malc

    malc Member

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    Thx I'll have a look.but I just had to lower the inter as it was backfiring through the exhaust.I'm now running 29.5 inter and 38 main.

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  8. BWG56

    BWG56 Guru

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    Decibel pop is a lean condition and maybe you went the wrong direction with the jet.
    Most are in the 31 -32 inter. and 74-78 main range with any mods
     
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  9. malc

    malc Member

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    Auxiliary bowl vent ? Is that the air jet ?

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  10. BWG56

    BWG56 Guru

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    #14 on the PDF
     
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  11. malc

    malc Member

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    So if I remove that will I need to up the inter to 31 again?

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  12. malc

    malc Member

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    cheers for your help,i removed the air vent and replaced the 31 inter,and seems to be running a lot better,gonna take her for a long ride and reset the carb again,and mabe try upping the inter a bit more as you said I may have gone the wrong way.franco suggested I up the main air jet aswell,whats your thoughts on that as well ?
     
  13. PROFLYER

    PROFLYER SWOLE
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    make sure you're up to temp and your idle mix is adjusted perfectly before you go messing with jets. Sounds like you're close.
     
  14. BWG56

    BWG56 Guru

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    Your welcome and I'm at 78 on the main
     
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  15. malc

    malc Member

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    I'm also at 78,are you at 31 on inter.do you think upping the main air jet would also help ?

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  16. BWG56

    BWG56 Guru

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    Well I am running the S&S dual runner air cleaner, the Vance & Hines 2 into 2 with the baffles still in and the 585. I was running 32 and 78 with the auxiliary vent screw out, while cruising at 50-55mph occasionally I would get a sneeze thru the carb, so based on S&S's recommendation, I went up to a 33 on the inter. and it eliminated it.
    33 seems big but with the tolerance on these carbs, no 2 are alike but similar, so you need to find out what works for yours.
     
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  17. malc

    malc Member

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    Once again thx,think I'm on the right track now,I'll get there in the end

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  18. ground pounder

    ground pounder Active Member

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    If you think you need a bigger main jet. The easiest way to tell is to pull the enricher knob up a little while your at running down the road. If it runs better go up one size. If it doesn't, than don't change the main jet!
     
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  19. malc

    malc Member

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    Hi guys,still trying to sort my running problems,have rejeted the carb as advised,but still juddering when trying to hold at steady revs,IE in trafic .when I check the plugs the front cylinder runs richer than the rear.I'm starting to think mabe it's electrical fault,new leads,coil,ignition,any ideas what it could be,on the wiring diagram it only shows three wires to coil,red,yellow and blue,but on the bike there is also a black and an orange that has been cut back.?

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  20. BWG56

    BWG56 Guru

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    Black and orange are to the key switch
    The front cylinder usually is always richer than the rear, did you eliminate the possibility of an air/vacuum leak?
     
    #20 BWG56, Jul 8, 2017
    Last edited: Jul 8, 2017
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