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Project The Second Fizzer

Discussion in 'Your 250cc Projects' started by Joker, Sep 28, 2016.

  1. Linkin

    Linkin The Apprentice Premium Member Dirty Wheel Club Contributing Member

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    If your original needles and emulsion tubes are suspect then fit the keyster ones and see how it goes.
     
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  2. Joker

    Joker If you want me find Club250 on facebook. Premium Member Contributing Member

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    The bike used to run fine with the same tubes and needles so I should be able to find a happy spot. Its just taking a while... new ones would make it easier to Start from the stock setting for sure. Maybe a little more playing to go first. I already sold it before I even finished so now I'm obligated to get it right lol
     
  3. Joker

    Joker If you want me find Club250 on facebook. Premium Member Contributing Member

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    Hmm so now I'm getting confused... I pushed the pilots back to 2 1/4 turns out and adjusted the idle which seemed to fix the boggyness at low RPM but we have the "I don't want to rev past 14kish" issue returning. So I swapped the fuel pump out. Now it's boggy again at low RPM and will sorta chug up to 16K but not go much higher. Messing with the idle doesn't seem to make much difference.

    I suppose switching the needles/tubes out might help some of the issue but i'm starting to think I might have a blockage in the carbies somewhere causing all these problems. The inconsistency in what is happening is amazing.
     
  4. Linkin

    Linkin The Apprentice Premium Member Dirty Wheel Club Contributing Member

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    Fizzer... running fine... hahahahaha! Sorry. I have my own fizzer nightmares in my memory. Mostly fixing previous bodge jobs and a few of my own screw ups.

    In all honesty I think you need to get the bike on a dyno and let an expert look at it at this point.

    But first, I would definitely try removing the fuel pump and filter, and just running the fuel tap straight to the carbs, and see how that goes. Inspecting the fuel tank strainers might be a good idea as well... and how old is the fuel? what grade is it? Some thinking outside the box is needed on this issue.
     
  5. my67xr

    my67xr Bike Enthusiast Staff Member Premium Member Contributing Member

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    Would it be your little fuel filter isn't flowing enough ?
    You could substitute the fuel filter for a double ended barb and see if it rev's out more.

    Swapping the new Keyster needle's and emulsion tube's might help if your's are worn.
    It will make the carby's a bit leaner off idle so it'll rev instead of the bog, night need to turn your mixture screw's back t o2 turn's out again though.

    When you swapped the fuel pump's over and the problem changed, does one flow more than the other ?
    Could do a side by side test on the pump's. Check how many cc's they flow in 5 second's and compare.
    Then to check if the filter is restricting it do a test minus the fuel filtert.
     
  6. Joker

    Joker If you want me find Club250 on facebook. Premium Member Contributing Member

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    It's really weird, the new pump seems throttled when it runs while the other one is free flowing. It's sort of a muffled "click" when compared to the old one which is pretty clear. Could just be the different mechanism. The outlets on the new one are 10mm instead of 8mm which are the fuel lines.

    Hmmm... the club guy said he'd take it as it is and play with it (or get a mechanic to play) but I just feel bad giving it to him without it running well.
     
  7. my67xr

    my67xr Bike Enthusiast Staff Member Premium Member Contributing Member

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    Not sure if you can compare the sound between the 2 pumps,
    especially with one having done 40,000km's ? and the other being new
     
  8. ruckusman

    ruckusman White Mans Magic Master Premium Member Dirty Wheel Club

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    Have you checked the pressure output from the two pumps - the fizzer pumps output a very low pressure of only 1.5 PSI

    If you cannot check the pressure output measuring the fuel height between the two pumps may be enlightening
     
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  9. Joker

    Joker If you want me find Club250 on facebook. Premium Member Contributing Member

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    Thanks for the thoughts again everyone. On Friday i bit the bullet and did another full carby clean. I reset the pilots to 2 1/4 turns out and put the rich cylinders (1 & 4 with larger main jets) up a notch on the needle. On Saturday I dropped her off to her new home in that condition. A final burst up the street of her new neighborhood was the best she's been, I'd almost bet taking those needles that I changed down a notch will probably fix it (although I've probably also said that before so who knows). The new owner is a club member who is happy enough to finish the final tinkering, so hopefully I'll still see it around in the near future.

    So this is where the story ends I suppose. Turning my attention now to the mexican fizzer - see where we end up with that now.
     
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