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Thread: 1998 R1100RT I pulled the cat code plug!

  1. #1
    It's a way of life! oldnslow's Avatar
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    1998 R1100RT I pulled the cat code plug!

    I pulled the yellow cat code plug today and went for a 1 hour ride. The bike is a keeper if I can make it run like this all the time! Surging gone, herky jery throttle gone, smooth idle, pulls smooth from down low in the rpm range, over all, a pleasant experience. Very rideable in town now!

    My bike is bone stock, 20000 miles.

    My question is, why did this make a difference. I have read all of the related posts I could find but the 'techno speak' goes way over my head.

    And what damage may this cause to my engine, if any.

    I discovered some threads about adding the Idle Regulating Valve after removing the CCP and disconnecting the oxygen sensor. That sounds intersting too. MPG doesn't concern me, because as it is now, the bike gets 0mpg because I don't like to ride it.

    I can tune a two stroke with screws, needles and jets as good as anybody, but this "open loop - closed loop - lambda- wide band -narrow band CO emissions" mumbo jumbo confuses me to no end.

    Sorry to bring up an 'oil thread' type of question, but I just need a plain speak summary of all the info I have gathered. Real world experinces would be helpful too.

    Thanks!
    Mike Davis
    "Old n Slow" It's a way of life!
    1985 K100RT

    1998 R1100RT

  2. #2
    Registered User roger 04 rt's Avatar
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    When you remove the Coding Plug on an R1100RT you have set up your motorcycle like it was originally designed to run without a catalytic converter. If you run premium, non-ethanol fuel you should get a good result. If you're satisfied with the idle you can skip the CO Pot (idle regulating valve). Red100Rt has described how he added a 1K pot at lower cost than the CO pot from BMW.

    This is a valid configuration which should be fine. It's possible that you could get some carbon accumulation in the exhaust but it doesn't seem to happen.

    It will be hard to understand what you've done without getting comfortable with the mambo-jumbo which is unfortunately the new plain-speak.

    RB

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    It's a way of life! oldnslow's Avatar
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    Roger, should I also disconnect the 0-2 sensor? My idle is fine, smooth and strong at about 1100-1200rpm. (my eyes aren't what they used to be and that gauge has small numbers!)I am going to try and find a shop that will analyze the exhaust gas for me. Am I interested in idle and high rpm gasses, or only idle?
    Mike Davis
    "Old n Slow" It's a way of life!
    1985 K100RT

    1998 R1100RT

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    Registered User roger 04 rt's Avatar
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    Quote Originally Posted by oldnslow View Post
    Roger, should I also disconnect the 0-2 sensor? My idle is fine, smooth and strong at about 1100-1200rpm. (my eyes aren't what they used to be and that gauge has small numbers!)I am going to try and find a shop that will analyze the exhaust gas for me. Am I interested in idle and high rpm gasses, or only idle?
    My opinion is that you should leave the O2 sensor in the exhaust and connected. That way it will stay heated and not be damaged. With no Coding Plug, its signal will be ignored.

    If you wanted to remove it you would have to plug its fitting on the exhaust and remove your fuel tank to disconnect it. Not worth the effort IMO.

    The shop should only check carbon monoxide level at idle. Let us know the number (probably a few percent) and there's a table that will let us estimate the air fuel ratio at idle.

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    It's a way of life! oldnslow's Avatar
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    Thanks Roger! What about damaging the catalytic converter? Am I risking this with the plug pulled? I don't mind if I ruin the converter as long it doesn't damage the rest of the motor. Thanks for all your help! You may have saved this bike from being banished to the back of the garage!
    Mike Davis
    "Old n Slow" It's a way of life!
    1985 K100RT

    1998 R1100RT

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    Registered User roger 04 rt's Avatar
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    Quote Originally Posted by oldnslow View Post
    Thanks Roger! What about damaging the catalytic converter? Am I risking this with the plug pulled? I don't mind if I ruin the converter as long it doesn't damage the rest of the motor. Thanks for all your help! You may have saved this bike from being banished to the back of the garage!
    I don't think you'll hurt the cat converter. With a richer mixture, although there are unburned hydrocarbons in the exhaust, there's no oxygen left to burn them so the cat won't get hotter than usual.

    At some level of richness there is the possibility of carbon accumulation but I don't think you're there. Get the idle CO number and you'll know how rich its running at idle.

    Power Commanders and Techlusions can add a lot of fuel than pulling the Coding Plug and I haven't seen any posts related to carbon accumulation from using them.

    Many R1100 owners have pulled the Coding Plugs.

    I think you should do a google search though if you're concerned.

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    Quote Originally Posted by oldnslow View Post
    I can tune a two stroke with screws, needles and jets as good as anybody, but this "open loop - closed loop - lambda- wide band -narrow band CO emissions" mumbo jumbo confuses me to no end.
    Yeah when you understand how simple the new systems are you are going to be quite impressed with yourself, trust me.
    Nowhere near as complex as a high-performance two-stroke.
    There's still a lot of fascination with changing exhaust systems for example but it makes precious little difference to the fuel-injected boxer.
    With a two stroke you have to tune the whole system all at once, makes it hard to experiment.

  8. #8
    It's a way of life! oldnslow's Avatar
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    MPG update

    After 350 miles of twisties and some 70+mph highway runs, riding two up, my mpg was at 46 mpg. Thats as good or a touch better than it was with the cat code plug inserted! Im a happy boy now!
    Mike Davis
    "Old n Slow" It's a way of life!
    1985 K100RT

    1998 R1100RT

  9. #9
    Registered User roger 04 rt's Avatar
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    I think you'll be satisfied as long as you run premium fuel, NO ethanol.

    If you get fuel that's 10% ethanol your bike will run fairly lean and may exhibit the surging again. With no Closed Loop program running the Motronic won't be able to adapt to the leaner fuel.

    When you get a chance I'd love to hear what your tailpipe CO Is at warmed up idle.

    RB

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    Ok, time-before-last time out with Rod we stopped and filled up with no-ethanol 91.
    My MPG went from 45-ish to 50.
    Theory: more energy in the non-ethanol fuel, you don't have the throttle open as far.

    Yesterday I pulled the yellow code plug, filled up with no-ethanol 91, rode most of the day, refilled at the same station.
    43MPG.

    It does run better. But...

    From the wiring diagram this looks like a simple 3-bit code, zero through 7.
    Pulling the plug must make the code zero.

    Any documentation on what the other 6 codes do?

  11. #11
    Registered User roger 04 rt's Avatar
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    Scott, There is more energy, though not a 10% difference.

    The stoichiometric ratio of E10 is 4% lower, meaning it takes 4% more fuel to hit the Oxygen sensors target of lambda=1. So when you use non-ethanol, the Motronic actually produces injector pulses that are 4% shorter induration than when you burn E10.

    Any difference beyond 4% is something other than the fuel.

    See this for coding plugs: http://bmwsporttouring.com/ubbthread...43#Post760243/

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    Quote Originally Posted by Roger 04 RT View Post
    Any difference beyond 4% is something other than the fuel.
    Well, the 45-ish did wiggle around quite a lot and the 50 was strictly a "hm that's weird that's almost 50 mpg".
    As in +- 10% close enough at the time.

    In my mind removing the plug was an experiment so I actually used a calculator...
    If I really want to know I'll have to get more scientific and have stricter controls.

    Thank you for the link that is fascinating.
    I think I'll put the yellow plug back in for now but it might be interesting to replace it with some switches.

    ps I really appreciate the dwell measurments I would have difficulty getting those myself.
    Last edited by scott.lambert; 06-23-2013 at 05:01 PM. Reason: ps

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    Quite a thread. More of a rope actually.

    It might actually be convenient to have a "low octane" switch in my neck of the woods.
    Or for someone GSing their way through Mexico.

    Any idea what octane we're talking about for the Swiss code?

    Is it necessary to reset the Motronic after changing the code plug?
    I thought there was an immediate seat-of-the pants difference just pulling the plug.
    Last edited by scott.lambert; 06-23-2013 at 06:44 PM.

  14. #14
    Registered User roger 04 rt's Avatar
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    My advice would be to run with the stock Coding Plug, except those with R1100s who want to run Open Loop with non-ethanol fuel. For most models, adjusting Lambda with something like an LC-1 (or the Device I've been working with Nightrider.com on) is more productive that changing Coding Plugs. The Plugs have very different meanings R1100 vs R1150. Here are a couple of examples from the document I have, written in French:

    R1100RT (MA 2.2) :
    - Sans catalyseur ..............................
    - Avec catalyseur ..............................
    - Version Suisse (Avec catalyseur) ..

    ....... Pas de fiche ......
    .... 61 36 8 366 282 ...
    .... 61 36 8 366 622 ...

    ................. .................
    ........ Jaune dor? ........
    ............. Bleu .............

    .............. .............
    ......... 30 87 .........
    ...... 30 86 87a .....


    R1150GS (MA 2.4) :
    - Avec catalyseur ..............................
    - Avec catalyseur (91ROZ) ...............

    .... 61 36 8 366 282 ...
    .... 61 36 8 366 623 ...

    ........ Jaune dor? ........
    ......... Gris Clair .........

    ......... 30 87 .........
    ....... 30 86 87 ......

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    I think ROZ is an abbreviation for the German literal translation of RON - Research Octane Number.
    In USA and Canada, the pump is labeled with (RON+MON)/2, and MON is typically 10 less than RON.
    (MON is Motor Octane Number, yes it is actually measured in a special adjustable motor.)

    Apparently Europe uses ROZ on the pump label.

    The sticker on the RT calls for 85 MON / 95 RON - or 90 at the pump.

    I would assume grounding pin 86 will retard the ignition to the point where 91 ROZ won't ping,
    which at a US pump would be 86.
    I can tell you the RT currently will ping like mad on 87.

    Coincidence that the pin labeled 86 is for 86 octane? Oh wait it's German. Probably just coincidence then.

    So, Roger, I noticed on the online catalog the 1100 isn't mentioned... are you going to offer the gizmo for th R1100, or is it hopeless ?

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