Stalling problem solved? Seems that way.

Discussion in 'Parallel Universe' started by MikeMike, Jan 23, 2013.

  1. MikeMike

    MikeMike Long timer

    Joined:
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    I've got an F650GS with a mid-2009 build date and pushing towards 50,000kms.
    Since new, I have been living with the stalling problem. The local dealer (who controls a monopoly in this part of the country with the closest dealership with a different owner being about 450kms away) could find no problem under the warranty. "They all do that, senor", was the response.
    Then, suddenly one day and without warning, my fuel pump controller failed (another story).
    It was replaced with the black powdercoated newer version and presto! Hardly any stalling, about a 99% improvement.
    I noticed when I gutted the old FPC, the upper socket, the black plastic one that fits into the controller, the contacts were merely piercing the solder on the little printed circuit board inside. Not really a cold joint per se, but a very odd effect where the solder was not "stuck" on the pins of the socket, it was merely touching them.
    Unfortunately, this is not something you can check as it requires you to gut the FPC from the bottom up and renders the part unusable except for the "roll your own" emergency bypass cable.
    If you still have a stalling issue, it might be money well spent to replace the FPC and see if it works. If it doesn't, you are not entirely wasting your money as at least you'll have a spare if the new one goes or if someone else's FPC goes south during a group ride.
    Just thought I would pass this on. At a $175 bucks a pop, you might think twice about the part swap, but you should at least educate yourself with the Tim Cullis emergency splice method to get yourself home (as I have mentioned before).
    #1
  2. GB

    GB . Administrator Super Moderator

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    When I had a 1200GS, I carried a spare controller with me.. later on, inmates devised a bypass cable solution to get the bike going again, for far less than the cost of a spare controller.

    It's important to learn the symptoms of the fuel pump controller as it's failing so you know what's happening and be prepared. The bypass cable is the simplest "fix" to get you on the road again.

    When I had a brand new 2011 F650GS, it would sometimes stall when I'm coming to a stop, as I pull in the clutch.. I wonder if that's related.. :scratch It only did it 2 or 3 times in the 2000 km that I owned it.. I attributed this to rider error.. although I couldn't figure out what the error; coming to a stop at a traffic light, I pull in the clutch and it would stall.
    #2
  3. MikeMike

    MikeMike Long timer

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    Yes, it was likely related to the FPC, with what was happening on your old F650.
    The bypass cable is easier if you simply gut an old FPC and roll your own bypass cable that plugs right into the existing wiring and is controlled by the igniton.
    Sending Burns Moto a pile of money is not the answer, anyone can build the cable cheap and do the splice bypass in a few minutes. Also, the idea of a heavy duty battery pigtail to go with the expensive cable they sell is throwing good money after bad, it is not needed, check the existing wiring and see if that is "heavy duty". Uh uh.
    All my opinion, I've had my controller fail with absolutely no warning. Bypass splice will get you home.
    #3
  4. JRWooden

    JRWooden never attribute to malice...

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    North Carolina
    My stalling was same as yours, or occasionally when taking off from a stop while letting the clutch out ... but it never seemed (to me) that either case was my fault when taking off I had fairly "healthy" throttle applied when it stalled, and when coming to a stop the clutch lever was already at the hand-grip when it stalled....

    There's no way to know, but I wonder if the BMS-K has some algorithm in it that modifies the FPC control line when it detects the clutch has toggled from engaged --> disengaged or vise-versa ... that would kind of make sense because if the clutch is disengaged you should be able to cut way back on the fuel pump output, and as the clutch gets let out you would want to give the output a healthy bump up in order to cover the new demand for fuel ...

    Maybe the way that was implemented it freaked out the controller.... :huh
    #4
  5. MikeMike

    MikeMike Long timer

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    And couple that with the lack of a normal flywheel effect.
    #5
  6. JRWooden

    JRWooden never attribute to malice...

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    yeah... what you said Mike!

    Has anybody weighed the new ventilated flywheel vs. the old model?

    Or more precisely speaking has anyone calculated and compared the moment of inertia for the old vs. new? :wink:
    #6