'99 F 650 FUNDURO Carb problem

Discussion in 'Thumpers' started by CarDOC, Nov 30, 2009.

  1. CarDOC

    CarDOC Adventurer

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    :huh :ear
    I have replaced needle and seats on both carbs and reassemble, Only to have the bike Die and won't re-start .Need HELP
    #1
  2. Mista Vern

    Mista Vern Knows all - tells some.

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    When it dies, is it flooding or what? Can you keep it running at all? If it was runnng before, than maybe you have a float sticking or something. Also maybe there is a vaccuum leak?

    You can get every answer to every technical question you have by going to the Chaingang web site: http://www.f650.com/

    Be warned though, you need to read all you can and do your research in the tech sections, as some guys do not want to deal with problems that have been discussed 50 times before.

    I will help you as much as I can but need more specifics on how the bike acts and how it dies.
    #2
  3. JPSpen

    JPSpen At Large

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    Keeping up with the Joneses, OK ?
    Turn the gas on....

    I know....

    open the bowl drains and let gas get into the system.

    You're either flooding or not getting gas. Pull a plug and see if it's wet.

    If everything else is ok then it should run...Chokes working ? Valves been set recently ? Tight valves will make an otherwise ok bike hard to start...You didn't say WHY you changed the needles and seats.

    What else besides the carbs did you do ?
    Also be sure you're getting spark...
    John
    #3
  4. CarDOC

    CarDOC Adventurer

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    OK original problem was carbs were leaking
    Replaced needle and seats.
    After doing that job the bike starts but only warms up then dies and wont re start.:ear
    #4
  5. Mista Vern

    Mista Vern Knows all - tells some.

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    Either gas is flowing too slowly to your carbs, or the needles are hanging up, you are out of gas, or the float levels are WAY off. I'd go back and take the bowls off and make sure everything is back in there right. If the bike worked before you need to re-trace your steps.
    #5
  6. DADODIRT

    DADODIRT Long timer

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    Hmmmm.
    I know this might sound far off, but have you considered the voltage recitfier?
    It gives the same symptoms as it would if you are out of gas.
    The bike will start, then stall as if out of gas.
    PM me if you are still having issues. I have some parts and a BMW shop manual for the early F650's.
    #6
  7. CarDOC

    CarDOC Adventurer

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    Anyone have info on float level setup and which carb L o :eek1 rR get the float holder with the JET?
    #7
  8. Mista Vern

    Mista Vern Knows all - tells some.

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    You will find all you need on F650.com, but you gotta put some research time in.
    #8
  9. mark1305

    mark1305 Old Enough To Know Better

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    I just did float needle assemblies in my 99. IIRC, the float hanger with the little orifice (jet) goes in the left carb. Remember which is which while you are working on them upside down. You can double check which hanger is which on the Max BMW fiche here http://www.maxbmwmotorcycles.com/fiche/DiagramsMain.aspx?model=F650&prod=091996-121999##

    It will be the carb with the enrichener/choke valve in it. And that should be the left one.

    If you didn't set the float levels right, it won't run. If the little o-rings on the float hanger brackets leak, it won't run right. You can't get them separately from BMW. But, I sent a bunch of my leftovers out of a batch of 25 I had bought to Prof - the founder of the Chain Gang at f650.com. If you aren't a member, join. Then ask Prof if he still has some of the little o-rings. He usually collects a small nominal fee for most stuff like that for the charities the Chain Gang supports.

    Setting the float levels is part black art. The trick is with the carbs in your hands (I know it will be a bear pulling them out again). To set the levels so that the float bodies are parallel with the flange on the carb body where the bowls go. You want the needle to just come to rest on the seat without the weight of the floats compressing the little spring plunger inside the needle at all. Basically holding the carbs on their side and watch the needles very closely to achieve that setting as you tilt them gently side to side to move the floats gently.

    Also, if you cleaned the carbs thoroughly, did you reset the idle mix screws to a basic startup position? Off the top of my head I want to say 1 1/2 to 2 turns out should get you a stable idle to start with if all else is right. But float levels control just about every circuit in the carb as far as mixture and operation goes.

    Good luck. It can be done. And sometimes it can be tedious.

    Edit: Oh here is a bonehead move I made putting the carbs back together because I was still in the mindset from working on my airhead carbs.... In one of my F650 carbs I put the little nylon spring perch thingy under the clip on the slide needle and did the other one correctly with the little nylon spring perch on top of the clip. When I started the bike up and revved the throttle the first time or two, the slide needle assembled incorrectly climbed right up into the slide spring and stayed up effectively dumping gas for near WOT through that carb and flooding the motor enough that it choked down and wouldn't even restart. Check those first even if you are sure you did it right.
    #9
  10. Mtncrzr

    Mtncrzr Just Kidding, not really

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    Look for leaks in the intake boots between the carbs and cylinder.

    It doesn't die when you turn the handlebars does it?
    #10
  11. CarDOC

    CarDOC Adventurer

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    Ok I will give another whirl
    THANKS a Sh TON:D
    #11