My F800gs STALLS LIKE ITS RUNNING OUT OF GAS! PLEASE HELP!!

Discussion in 'Parallel Universe' started by chunter, Jan 3, 2009.

  1. DolphinJohn

    DolphinJohn Caveman

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    See that?
    Montreal.
    That's Canada.
    Canada= no canister.
    No canister=no stall.
    It's science.
    :D
  2. bxr140

    bxr140 Flame Bait

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    I agree that the canister itself its probably not the source, but I wouldn't rule out other parts of the system just yet. The fact that there's a BMW memo on the tank venting in the first place is a pretty good indication of that. The electronic solenoid could be a culprit, as could the vacuum system in general.

    As noted, I've noticed a real improvement (NOT elimination though) of the "twitchy" throttle since disconnecting the hose from the solenoid to the throttle manifold. This improvement may be associated with the cycle of the solenoid. I THINK the way these types of systems are designed, the solenoid is only open when the engine is idle, then it cycles closed once you raise the RPMs.

    I also don't have the fuel smell problem you've indicated, and there's DEFINITELY no "purging gas onto the ground".
  3. The Griz

    The Griz Long timer

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    Just so you know, if you've disconnected the hose that goes from the output side of the fuel tank breather valve (that houses your supposed "solenoid") to the throttle bodies, you're letting unfiltered air into the engine (via the throttle bodies). I wouldn't recommend that. Of course doing that is going to smooth out the twitchy throttle. You're letting way more air into the fuel delivery system! And unfiltered at that!

    I don't mean "masses" of fuel purging from the tank. I mean just a little bit. Just like every other motorcycle that has a pressurized fuel system. Enough to smell and see. On every motorcycle I've owned and ridden there has been a tank purge valve with a hose that purges very small (drip) amounts of fuel liquid and gases. If it doesn't do so, then the system is not operating properly (tank not venting properly), and I would get it checked out. So the fact that mine is actually purging like it should does not indicate a "problem", it indicates proper operation. The fact that yours isn't purging out of the purge valve is a problem, and to me is indicative of your stalling problem.

    Oh, and it sounds to me like you haven't actually fully removed your canister. I thought you mentioned earlier that you just unplugged some hoses and left things in place. if you left the hose that comes from the purge valve on the tank plugged into the canister, that would be why you're not smelling or seeing gases. They're going into the charcoal canister!
  4. DolphinJohn

    DolphinJohn Caveman

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    I had a chance to ride the bike today. No rain but I did notice that the bike is idling slightly lower than before. It used to idle at about 1400 when cold starting (cold engine, not air temp-- Fla=85+). If it dropped down lower than that it would idle rough and sometimes stall. This was in dry conditions.
    Now it idles at about 1100 but nice and smooth. I had it out on the "highway" at 75-80mph, and also down a little gravel/mud/big puddle road.
    The bike is running great and no gas smell.
    I will order and install the K&N prefilter drycharger material in the air intake tubes, and hopefully I will have my stalling issue resolved. Fingers crossed.
  5. bxr140

    bxr140 Flame Bait

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    :confused

    As noted two posts ago, I plugged the hose.

    Also as noted two posts ago, I started the bike without the hose plugged out of curiosity, and it idled like crap (similar to the stalling/poor running incidents) which is exactly what you'd expect form an engine with a vacuum leak. Nobody would expect an engine with unmetered air to run anywhere near correct. I didn't ride it around the parking lot, but perhaps I will sometime this week, just to see if it mimics the conditions folks (including myself) have experienced.

    And FYI, it is not a 'supposed' solenoid, it is a solenoid. :deal

    I park my bikes in my garage, and I've never had a motorcycle smell or leave visible indication of gas dripping. Okay, except for my KLR...but that bike had issues... :puke1

    I think you might be a bit premature with your diagnosis, mostly because I haven't had a stalling or poor running problem for 3 months and 3000+ miles.

    I didn't fully disconnect the canister from the system. I purposely only unhooked the hose from the solenoid to the manifold so only one variable was changed--specifically, the evap system to the engine. As BMW has already acknowledged, some bikes have a problem with the evap system to the tank (the 'tank vacuum' problem), but I didn't want to make both of those changes at the same time, especially since my bike didn't indicate a vacuum problem when I took it in for the fuel gauge.
  6. The Griz

    The Griz Long timer

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    I didn't claim to "diagnose" anything.

    As I said before, if you didn't actually disconnect the hose from the fuel tank purge valve to the input of the canister, then you wouldn't have any smells or liquids. It's all in the canister.
  7. DockingPilot

    DockingPilot Hooked Up and Hard Over

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    My tech removed my cannister without much prodding. They dont like them as they can be problematic. Every bike I have owned, I removed them. It's a pretty popular procedure on motorcycles as these things are not perfected yet in the eyes of a lot of riders. Of course there was no paper work :lol3
    No gas spew either of course.
    I just rode the bike very hard for 230 miles at a dual sport event through some sections of technical stuff. She performed flawlessly and never stalled once. Ill post a report on my (now changed) opinion on the 800 in good offroad conditions soon. But in short, the bike is just the unbelievable and deserves credit. Some of the orange boys were taken by surprise as the big 800 was nipping at their rear tire at times :lol3
    :clap

    She never stalled but she did get a bit dirty over the 2 day event.
    [​IMG]
    [​IMG]
    [​IMG]
  8. Magile

    Magile "What exit?"

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    :clap Good job Frank! They look good dirty. Looks like you had a blast! I'm looking fwd to hearing how the Bitubo make over worked out.

    - M

  9. RedHawk47

    RedHawk47 Adventurer

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    I haven't been following this thread closely because my bike doesn't stall. I rode for an hour is pouring rain and slush this weekend with no problems. (Monarch Pass, 11,312 ft, 33 deg)

    Some questions and food for thought:
    Where does tube #22 go?
    Can it be getting water into it?

    Some valves like those in that tube set are designed to vent air in both directions but not allow liquid thru. So they let air out as the fuel warms up and expands, and let air in as you use fuel. But the air flow rate is so small that you cannot detect it blowing of sucking on the tube.

    So, if water gets up the tube to the valve, as you use fuel, it will try to suck the water thru, but will not be able to, and also will not be able suck air in, resulting in a vacuum in the tank and fuel starvation. Sympton: vacuum sucking sound when you open the fuel filler cap.

    Related info. The KTM950Adv had related problems. Removing the canister did not solve them. Opening the tank vent valves (in the gas cap on that bike) did solve the problem. I worked for me.

    On the KLR there is a vent tube off the carb that feeds down by the center stand. In a stream crossing it can suck water up and cause problems. The solution is the "T"; a branch that goes up under the seat.

    Does this fit?
  10. Motoriley

    Motoriley Even my posing is virtual

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    Did the T-mod to my KLR as recommended on the web. I made it across the next deep water crossing, my buddy's didn't. A lot of folks seem to have crossed deep water with no issue on the F800 though.



  11. The Griz

    The Griz Long timer

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    Hose #'s 18, 19, 20, 21, and 22 in the top picture of the tank goes to the canister intake and is actually hose #'s 8, 9, and 10 in the bottom canister picture, and is fully sealed. The output from the canister to the throttle bodies which is #7 in the bottom picture goes straight to the throttle bodies and is also fully sealed. The hose #6 in the bottom picture goes straight downward as a drain from the canister (which nothing typically drains out of because the canister is doing its job). Being that it goes downward, water cannot get into it. Hence, the system is fully sealed from water penetration.

    [​IMG]
    [​IMG]
  12. The Griz

    The Griz Long timer

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    I just got back from a 45 minute ride in the rain at 70 mph. No stalling. Not even a hiccup. I wonder if the fact that I just installed a K&N air filter has anything to do with it. Most people's initial thoughts would be no. However, the fact is that the stock air filter is paper. Paper is prone to getting water logged, which then would prevent air from passing. It turn stalling the bike. The K&N I installed is oiled woven cotton. I also used the K&N sealing grease that goes around the perimeter of the filter to prevent leaks.

    P.S. My bike has never had a stalling problem in the first place. Also, I still have the charcoal canister on too.:dunno
  13. R75/5

    R75/5 Adventurer

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    Although the threat is meanwhile a bit stale, this bit of information might be somewhat relevant:
    I stumbled over a post in a german F800 forum describing occasional stalling after riding in the rain. Although the initial stalling occured during a bad weather run, later failures occured even during rides in pretty good conditions and also pretty unfrequently. After faffing around for quite some time without being able to isolate the problem, the guy did finally get around reading out the error memory: It flagged up several "fuel pump failure" warnings.
    This motivated him to have a closer look at the fuel pump / fuel pump electronics: Turned out that although the fuel pump assembly under the seat is protected by a rubber seal (directly under the drivers b...), he found to his surprise under the membrane quite some moisture. Dismantling the assembly even revealed the plug for the fuel pump partially submerged.
    Careful drying, subsequent contact cleaning and changing the rubber seal (30$) did the trick for him: No re-occurance.
    Don't know if this is only an isolated case, but maybe worth for the people experiencing similar problems to have a look under that rubber membrane...
  14. DolphinJohn

    DolphinJohn Caveman

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    Griz, can you post up a schematic for this?
  15. WoodWorks

    WoodWorks House Ape

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    Will I do?

    [​IMG]

    Incidentally, if you want to, you can access all of these fiche files here.

    David
  16. DolphinJohn

    DolphinJohn Caveman

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    Whoa.... nice. I thought Griz had exclusive access to classified files. :D

    Thanks!!
  17. bxr140

    bxr140 Flame Bait

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    Fiches have been up on bikebandit.com for a while now, FYI.
  18. DockingPilot

    DockingPilot Hooked Up and Hard Over

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  19. Bayner

    Bayner Long timer

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    I didn't know that, thanks guys!!
  20. drrags

    drrags Dorkus Malorkus

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    No matter whether this applies or not, this is not good. Reminds me of the 950 KTM fuel pump issues. I'm gonna get off my ass tonight and take a look at mine.
    Thanks for that info, cool! :clap