R1150GS won't push past 3500 rpm

Discussion in 'GS Boxers' started by CoalCreek, Mar 20, 2019.

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  1. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

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    Seems to me that one of the fuel lines inside the tank is leaking internally. As the RPMs hit a certain point, the fuel pressure is not high enough to keep up with demand.
    #21
  2. lewisjr1

    lewisjr1 Long timer Supporter

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    I mentioned that possibility a day or two ago, and since then the qty. of posts have exceeded OP's ability to actually work on the bike. We're such an impatient bunch of posters!
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  3. C.Hensley

    C.Hensley Been here awhile

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    Also and I know it seems obvious...I have had a bad sparkplug and or plug cap cause the problem you describe on more then 1 occasion.
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  4. NoiZboy

    NoiZboy Dirt to Track and Back Again

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    My suspicion is the same as Jim's - if the idle is fine up to a certain RPM, I'd be suspicious you don't have enough flow for fuel delivery above a certain point. Spark that cuts out above a certain RPM is also a possibility, though. Will be interesting to hear what you learn!

    UPDATED: corrected "pressure" to "flow" as per Roger04 RT's comment below ... I used the wrong concept/term.
    #24
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  5. roger 04 rt

    roger 04 rt Long timer

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    There can be enough pressure, but not enough volume. The fuel pump is always running at maximum. Some goes to the injectors and what they don’t require goes back to the tank.

    Measure the volume of fuel returning to the tank at idle. If it is 2L/min the hoses and pump are good.

    This is the first thing you should diagnose.
    #25
  6. ACD

    ACD old nOOb

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    I had a similar problem with my 1200, it was caused by a bad stick coil. Fortunately I had access to a good coil, replaced the suspicious coil and confirmed the problem.

    All good until around 4K rpm, then rough, as if engine electronics or fuel supply was restricted.

    When trying to pinpoint the problem I took it to a dealer, they plugged a laptop and said it was a bad HES... Which was brand new and working perfectly.

    I read here, in this forum, how to test the coils, and confirmed later testing with a good coil.
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  7. Bruincounselor

    Bruincounselor North Plains Drifter Supporter

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    Unfortunately the 1200 and 1150 systems are not similar enough for your data to be useful. No stick coils to go bad on this 1150, for example.
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  8. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

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    His model of GS predates the stick coil. Otherwise I would agree with you.
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  9. BluByU

    BluByU Been here awhile Supporter

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    Pull the plugs and have a looksee.
    If you have a timing light, put it on and take the bike for a ride, Ya might be losing spark. Real simple and no cost test.
    But JVB might be right on with the line in the tank. If you decide to pull the pump just go ahead and replace the U hose and filter while you are there no matter what they look like. If not you will be doing at a less fortunate time.
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  10. Roll-sen

    Roll-sen Hater be Hatin'

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    And a +1 on the earlier mention of CCP. I experimented with every possible "color" using jumper wires and and one particular setting would not allow rpm above approx 3500. This was also on a 2000 GS. The jumper configuration mimicked one of the actual available BMW plugs (forget which one). This CCP scenario seems unlikely based on OPs situation, but just wanted to throw it out.
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  11. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

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    You can swap jumpers all day long, but none of them will cause the bike to stop accelerating past 3500 RPM.
    #31
  12. GS Addict

    GS Addict Pepperfool Supporter

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    Do what Roger says.
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  13. rg sw wa.

    rg sw wa. Long timer Supporter

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    :lurk
    #33
  14. mcatt1

    mcatt1 n00b

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    I had a '00 1150GS with what sounds like exact same problem (everything fine until 3,500rpm, beyond which the bike became VERY unhappy!), replacing HES fixed it immediately and permanently. No thanks to the local BMW shop BTW, they plugged it into their computer, no error code and no clue but they still charged me $200, problem was solved from suggestions I got on the site here!
    #34
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  15. GS Addict

    GS Addict Pepperfool Supporter

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    I have never heard of that...interesting.
    I've rewired lots.
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  16. lewisjr1

    lewisjr1 Long timer Supporter

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    Have we heard, I mean read, the outcome? I'm genuinely interested.

    I'd first considered the HES as a possibility, but soon moved into the camp of burst internal fuel line.

    OP, we desperately need an update!
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  17. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

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    Me either. HES doesn't generally act like that.
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  18. Mike Ryder

    Mike Ryder Kriegerkuh Supporter

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    A leaking plug boot can do that. I know having poked a hole in one. At a certain rpm or load it would cut out.
    But it’s likely a split hose
    #38
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  19. Jim Moore

    Jim Moore Souped-Up Weasel

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    That exact thing (almost) just happened on my R1100RS. The solder on one of the wires broke and it would lose contact at 6000+ rpm. I chased that one for awhile.
    #39
  20. GS Addict

    GS Addict Pepperfool Supporter

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    Where is there a soldered joint on a stock HES? They are all crimped connections.
    #40