R1150GS won't push past 3500 rpm

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

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  1. mcatt1

    mcatt1 n00b

    Joined:
    Dec 30, 2014
    Oddometer:
    7
    Location:
    SF Bay Area
    You've probably already sorted this out, but my bet is that you need to replace the ECM (Electronic Control Module)--I had the EXACT same problem on my '00 GS, none of the local shops (including the BMW place, who put it on their diagnostic computer!) could sort it out but I picked up on a thread on the site here, bought and installed a used ECM on eBay for a couple hundred bucks and BOOM, problem fixed!
    #61
  2. ilias1972

    ilias1972 Adventurer

    Joined:
    Nov 12, 2017
    Oddometer:
    35
    Location:
    greece
    i have the solution for my problem.
    In my case... i was have three little problems. All of them was on the right hand cylinder.
    1. Bad throttle cable on the right hand throttle body. One wire of the wirerope was broken. Actually a piece of wire (about 5cm) was missing. Probably someone "mechanic" was put his little finger here. For that reason I did not notice it.
    2. A Little vaccum leak betwin right hand cylinder and throttle body at high RPM.
    3. Bad valves gaps at right hand cylinder. Gaps are too loose.
    So...
    About No 1. I replaced three throttle cables. I made my owns DIY cables. ATTENTION! This procedure need particular attention to the accuracy of the dimensions.
    About No 2. Good cleaning the rubber boots of the throttle bodies. A little-little sticky grease and back to the cleaned cylinders.
    About No 3. There are some issues about the high temperatures this summer in Greece. But a few days ago the weather was cool enough. So i wake up early, I wash the bike and i'm doing a fine-fine valves gaps adjustment at 24C.
    Throttle bodies balance and the bike run REALLY GOOD like a new one!!!
    I hope my case to help someone in the future.
    The details on these bikes makes the different!
    Thanks all of you again and sorry for my English.
    #62
  3. CoalCreek

    CoalCreek n00b

    Joined:
    Mar 20, 2019
    Oddometer:
    3
    Location:
    Colorado
    Hi All, OP here. My apologies for the long hiatus. You all certainly deserved a quicker response. After having to set this project aside for a year, I've been tinkering for the past couple weeks. I still have the issue where I hit 3500 and the bike just oscillates +/- 200 rpm.

    Things I've done / discovered over the past couple weeks:
    • Replaced the HES with a rebuilt unit
    • Fuel pressure appears to be fine
    • Fuses are fine. I'm not certain how to check the functionality of a relay, but everything is clean and seated
    • All cables are seated
    • Cat code plug pulled for 10 minutes after the HES was replaced
    In the course of trying things out, I noticed that my left cylinder wasn't as hot as my right. It was warm, but not hot. As in, I could have grabbed the pipe. I pulled the left spark plug wire and the bike's behavior is nearly unchanged! I switched the plug wires and tried to independently run the left, no luck. I also replaced the plug. So I think the wires and plugs are fine. I took out the left plug after this testing and it appeared to have fuel on it, so there is some level of fuel making its way to the left cylinder. This week I'll pull the injector to see how it's actually spraying.

    I'll keep you posted as things progress.
    #63
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  4. GS Addict

    GS Addict Pepperfool Supporter

    Joined:
    Sep 24, 2006
    Oddometer:
    7,374
    Location:
    Sunshine Coast B.C.
    You need to do a compression test
    #64
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  5. Jim Moore

    Jim Moore "You ain't black!"

    Joined:
    Dec 24, 2001
    Oddometer:
    35,899
    Location:
    Jax, FL
    Yep.
    #65
    rg sw wa. likes this.
  6. Andrew

    Andrew Optimus Primer Administrator Super Moderator

    Joined:
    Sep 25, 2001
    Oddometer:
    23,825
    Location:
    Eastbania
    Did you observe spark on the left???
    #66