2008 F800GS engine dies at 6500-7000rpm

Discussion in 'Parallel Universe' started by jerryga, Mar 25, 2017.

  1. jerryga

    jerryga Adventurer

    Joined:
    May 7, 2014
    Oddometer:
    12
    Location:
    Finland
    Hello, I tried searching but could not find anything with google or the site search.

    Anyhow, I've got a 2008 F800gs with 58 000 km. Modifications are lithium battery and 15 tooth sprocket. End of last season the bike started dying on hard acceleration. I suspected it was the side stand switch as it always happened on bumpy off-road riding or when pulling a wheelie.

    Today I got to ride it first time for this season. When riding out from town the engine died a few times when I changed to neutral in traffic lights. I guess the battery was a bit down on power after the winter even as I stored it in a warm garage. This did not happen anymore after I kept the RPM up for a while. But later when I got to open roads it always died at around 6500 rpm and after half a second it continued accelerating from about 5500-6000 rpm all the way.

    My question now is what could be the problem. I was thinking if I can try a normal battery from my WR250r or if that is too weak on the F800gs. Second thing I might try to use some injector cleaner in the gasoline. I also have a second hand side stand switch cable and switch that I can try if needed.

    I appreciate any help and if anyone have had anything similar?

    Ending with the goods news. I had changed my rim to a new excel rim to get rid of the original very much abused rim. Very smooth riding on asphalt now :)
    #1
  2. JimsBeemer

    JimsBeemer 2017 R1200GSA, 2016 R1200RT Supporter

    Joined:
    Jan 4, 2014
    Oddometer:
    810
    Location:
    Redding, CA
    Does it die as in you have to pull over to a stop and start it up, or does it just temporarily cut out, and then kick back in while still at speed but after RPM's drop a bit, like when you hit the red line limit?


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    #2
  3. jerryga

    jerryga Adventurer

    Joined:
    May 7, 2014
    Oddometer:
    12
    Location:
    Finland
    The engine does not turn off completely I can continue riding. Last year it happened that I had to turn off ignition and start again. That's why I suspected the side stand.
    #3
  4. Juozaz

    Juozaz Juozaz F800GS Blonde

    Joined:
    Feb 22, 2010
    Oddometer:
    61
    Location:
    Lithuania
    Hi, I has this situation before, please check fuel tank ventilation, hose of engine bottom.

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    #4
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  5. JimsBeemer

    JimsBeemer 2017 R1200GSA, 2016 R1200RT Supporter

    Joined:
    Jan 4, 2014
    Oddometer:
    810
    Location:
    Redding, CA
    Good suggestion - I had similar issue with my wife's F800ST.


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    #5
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  6. jerryga

    jerryga Adventurer

    Joined:
    May 7, 2014
    Oddometer:
    12
    Location:
    Finland
    I will check it tomorrow and hope for the best. Thank you,
    #6
  7. jerryga

    jerryga Adventurer

    Joined:
    May 7, 2014
    Oddometer:
    12
    Location:
    Finland
    All right. I had open #17 in below picture and tried to blow both ways and easy so if I understand correctly it should be okay? Or do I need to open the valve from where the pipe comes from?

    I also tried to record on my phone when keeping steady rpm at around 6500 rpm. But it was only wind noise and shaking :baldy from the ram-mount.



    What I wanted to show is how the engine cut off on load at 6500 rpm but can continue to accelerate after one cut off.

    So have I fine anything correct?

    Attached Files:

    #7
  8. AntReed

    AntReed Been here awhile

    Joined:
    Nov 17, 2014
    Oddometer:
    300
    Location:
    Kent, UK
    Possibly the stock coils are bad? I had some similar symptoms on my 1200, isles fine, smooth acceleration fine but hard acceleration caused a stutter


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    #8
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  9. jerryga

    jerryga Adventurer

    Joined:
    May 7, 2014
    Oddometer:
    12
    Location:
    Finland
    Been on a few work trips and could not work on the bike. But had a good mechanic helping out. Now this is finally solved. Timing chain was changed and one intake valve shimmed. Now it works perfectly again. Thanks for all the help.
    #9