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

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

  1. DockingPilot

    DockingPilot Hooked Up and Hard Over

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    Why not just tweak the ducts ? looks easy enough. I'm certain the mill doesn't need the "ram air" effect. Make it faux air inlet like the tank.
    Thinking out loud here.
  2. ROYAL COACHMAN

    ROYAL COACHMAN Long timer

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  3. DockingPilot

    DockingPilot Hooked Up and Hard Over

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    Thanks Glen, glad you enjoyed them.
    Frank
  4. bxr140

    bxr140 Flame Bait

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    Nobody is (or, at least, I'm not) contesting that water can get in the airbox through the intake ducts.

    I'm just not convinced that standing water in the airbox is actually the problem.

    Somewhat releated, here's the "Intake Sound System"
    http://www.realoem.com/bmw/showparts.do?model=0229&mospid=50779&btnr=13_1249&hg=13&fg=20
  5. ROYAL COACHMAN

    ROYAL COACHMAN Long timer

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    I somewhat understand your point, but how would you explain my F8 suddenly runs fine in the rain after installing the temporary fix I posted pic of?

    In 3 major thunderstorms beginning in December of 2008 to the present, My
    F8 has stalled aprox 15 times in a heavy downpour.

    It did not stall during the last heavy rain about a week ago.

    Glen
  6. bxr140

    bxr140 Flame Bait

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    You didn't understand what I said.

    I'd like to know *why* your blockoff plates seem to eliminate the stalling problem--something a little more analytical than "because water can't get into the airbox now".

    Motorcycles have been rolling around for years with ram-air systems that are much more exposed than the 800GS...which is really just forward facing, aesthetically pleasing intakes rather than 'ram air'. Why don't they have a problem, especially considering that they're designed to cram as much of the atmosphere (and everything in it) into their airboxes as possible?
  7. ]I)Money

    ]I)Money D NOT I

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    shape of the airbox, maybe? The F8 box has a depression in the bottom, with a valve in the middle of it that sucks air(or water) directly into the engine when it opens
  8. ROYAL COACHMAN

    ROYAL COACHMAN Long timer

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    You are correct about ram air intake design on other motorcycles not having problems, but my F8 seems to be different in that regard.

    The block-off plates are angled @ about 45 deg to deflect rain, yet retain an open space behind the plates to allow the engine to receive air.

    With plates installed I have a dry air filter in heavy rains. I know this because I inspected the air box and filter after a recent ride in a downpour.

    With plates removed( stock)I have a very wet air filter and standing water in air box.
    I can only assume that the plates block most of or all of the water from entering. (logical conclusion)

    AS to the physics of why this ram air set is having problems and others do not........... I'm not that intelligent!

    Sorry for being so dense but I hope this makes it clearer.
    Glen
  9. shleppy

    shleppy Shlepdawg on da smoov tip

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    Is this issue pretty much isolated to the F800GS? Anyone had the problem on the F650 twin? I just read the entire thread and noticed only one specific mention of the issue on a F650 twin. (could be that I missed when someone mentioned it happened on their F650 twin).

    The reason I mention this is due to the air intake difference between the F800 and F650. If this issue is pretty much exclusively on the 800GS, that might point some blame at the intakes. (Although the bikes obviously have some ecu programming differences..so the ECU could still be the culprit)

    Just a thought.. :D
  10. mr7q

    mr7q Stupid and Contagious

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    The scientist in me would want to see if rain is the problem by putting water in the airbox directly and seeing if it causes the stalling problem. That way you can remove the ram-air system as a variable.

    However, the pragmatist in me wants somebody else to do it... :lol3
  11. ROYAL COACHMAN

    ROYAL COACHMAN Long timer

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    My service manager did just that on a F800 demo bike. He took out the air filter and poured water from a bottle into the air box while running at idle with the result being a stall. Repeated this with the engine running at 1/4 throttle or higher with NO stall. I was there to witness this.

    It seems the idle air by pass valve sit on the bottom of the air box and cannot handle the influx of water, however at when the bike is off of the idle circuit it does bog a bit, but no stall. Run the motor up to 4000 rpm and the motor seemed to fine while pouring several ounces of water into the throttle bodies:eek1

    My service manager told me that some mechanics have used spray bottles to inject water into engines to clean carbon deposits with the steam created by the water:dunno

    Personally, I would like to clean my carbon deposits the old fashion way.................. WOT down the freeway:D

    Glen
  12. Surfdog

    Surfdog Been here awhile

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    go to the GS Recall thread... us the link to look at the recall items. it talks about a possible problem if the wiring is not secured under the airbox. The wiring could possibly rub a small hole in the harness causing it to short out & the bike stalling... I don't remember all the specifics.. but it is mentioned on the site... hope this helps !
  13. bro

    bro n00b

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    My F650gs twin stalled in the rain. But only in a horrible storm with wind blowing sheets of rain. I have posted that on this site and maybe it has already been read about. I am absolutely stupid about mechanics, but I thought it was the air intake just because it is a straight shot from outside to inside and it acted like water got into it. I have been in rain when it didn't stall, but it wasn't very windy, just raining. The air intake looks different but it is in the same position. I don't see much difference in the air intake except for the looks. Other than that it is a straight shot and the guts appear to be the same. But what do I know??:huh
  14. riders

    riders Adventurer

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    My wife's 09 650GS has died a couple tmes in the rain; the first time it had been sitting out in an all day thunderstorm; the bike started fine but then was running crappy and died when she slowed and went around a corner. The second time was when she had ridden seven miles to work and pulled into her parking area and it died and was running rough before she stopped. We called the dealer and next time we are in they will put a hose to it but we might try partially blocking the air intake if we see it may be ridden in the rain?????
  15. DolphinJohn

    DolphinJohn Caveman

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    I rode yesterday in torrential rain for 100 miles. It never let up.
    I'm talking about the kind of rain that looks solid red on the radar, with the
    "severe thunderstorm warning" box around it. Visibility about 100 ft..
    Flashers on, 35-40 mph just trying to get through it to get home.

    The bike would run ok, but stall most times when I stopped. (wouldn't idle)
    It would restart, then idle ok.
    It's kinda scary when you downshift to slow for a light and the bike stalls when you pull the clutch, but you didn't realize it stalled, so you let the clutch out and the rear tire just slides on the wet road for a few seconds before the bike starts.

    My tank was getting low, I stopped to refuel. When I opened the cap, there was so much vacuum it was hard to open. I refueled, and the bike ran perfectly all the way home.

    I'm convinced it is the full canister preventing venting that causes the stalling. When the tank is full, there is not enough space for vacuum.

    I don't know how the canister gets filled. I'm taking it off as soon as I get a day to work on it.
  16. DockingPilot

    DockingPilot Hooked Up and Hard Over

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    John, my dealer (ssshhhh) removed mine. I qoute "those things suck, everyone should remove them"
  17. ROYAL COACHMAN

    ROYAL COACHMAN Long timer

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    John your experience in the rain sounds like a mirror image of mine with the exception of vacuum present in the tank. I can not remember ever having that. I know that the carbon canister would fill up with water while riding in heavy rains as you described. (canister is now gone)
  18. DolphinJohn

    DolphinJohn Caveman

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    Since removing the canister do you have stalling problems in heavy rain?
  19. ROYAL COACHMAN

    ROYAL COACHMAN Long timer

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    No stalling in heavy rain since installation of block-off plates.(removed canister later)

    However just recently, the bike has stalled in 70 deg /with blue skies.
    Go figure:dunno
  20. chunter

    chunter Adventurer

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    Was the bike hot when this happened? Was the tank half or less full?

    I'm certain that this is going to be an ongoing problem with the F800gs. I got mine back from the dealer about 5 times for the same stalling issue. I'm in Hawaii, so the weather is generally pretty hot. The bike would run fine when the tank was full, then it would run down, and on hot days it would stall. It wouldn't run properly until it either cooled down totally, or I filled the gas tank.

    I'm almost certain that the reason is that the fuel pump sits inside the gas tank, and when the tank is full, the fuel actually cools the pump down. When it is hot outside, and the bike is hot, and the fuel tank is down, the fuel pump is exposed to the heat and this causes some kind of electrical interference. I have now had three different fuel pumps in my bike, and I'm almost certain this is the issue. I'd be willing to bet money that as the summer warms up, there will be many more F800gs owners suffering from the same problem.