BMW K100RS Tech Thread

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    1 of 88
    Yermo
    5 years ago
    A thread for all topics related to K100RS tech.

    This is mostly a thread where I can store links that I find since adding links directly to the index (via the Links menu item) is currently broken.

    K-Bike history: 
     
    2 of 88
    Yermo
    5 years ago
    K-Bike after market electrical parts: 
    Link #6808
    Yermo
    5 years ago

    BMW K Motorcycle Parts

    New inexpensive BMW K motorcycle parts. Battery cables, voltage regulators ,fuel pumps, ignition cables, and much more!

    http://www.euromotoelectrics.com/Se...
     
    3 of 88
    buffalo
    5 years ago
    $79 for a replacement ignition module? Not bad...
    4 of 88
    Yermo
    5 years ago
    More info on the ignition control unit used on the '92 K100RS. It's a bosch unit Bosch part # 0 227 100 200 


    Link #6818
    Yermo
    5 years ago

    Bosch ignitionmodules

    Bosch ignitionmodules - Download as Text file (.txt), PDF File (.pdf) or read online.

    http://www.scribd.com/doc/71992349/...
     
    The bosch part # for the connector is apparently:  1 287 013 005.
    5 of 88
    Yermo
    5 years ago
    Wiring diagram, the "Output Stage" is the ignition control module. Note that pin 2 (Black/Blue) also goes to the tachometer:


     
    6 of 88
    Ian
    5 years ago
    Getting a 404 on that link.  If you can still find the page, better make a local copy of the image/data/whatever.
    7 of 88
    Yermo
    5 years ago
    Thanks for the heads up:

    8 of 88
    Yermo
    5 years ago
    I decided to try replacing the Ignition Control Module, which is mounted on the forward side of the battery "box",  to see if that might solve the strange "cylinders 1 & 2 cutting out randomly in addition to the Tachometer dropping to 0" problem.

    Interestingly, I could tell immediately upon starting the bike that something was different. It started much more easily and ran smoother at idle. I also noticed that at speed it vibrates differently. 

    Also, fuel economy has improved dramatically. I'll know at the end of this tank by how much but it seems to be quite a bit. Others have reported that the rich fuel smell is gone from the exhaust.

    However, the bike is running warmer than it was before. My hypothesis was that the ICU was now causing more complete combustion which was leaning things out. Maybe? 

    It took it up to Bob's today to check the mixture. It ran hot on the way up. Unfortunately, it turns out that my mixture hypothesis is incorrect as the mixture had not changed at all.

    It does seem that the temperature gauge is failing as it reads inconsistently. 

    Steve, the awesome tech up there, gave me a laundry list of things to look at for possible causes for it running a bit hotter than I like. The bike is apparently not getting close to overheating, it's just running hotter than before (which may actually be correct). Hard to tell at this point. I do remember when the bike was newer it did run noticeably hotter than it has for the last few years. I had thought, possibly erroneously, that putting the Remus exhaust on and tuning the mixture to that cooled things down. Maybe the ICU was the cause. Not sure.

    Steve is still in touch with the early K bike expert that used to work on my bike at Bob's. It turns out that my bike is the only 16V K100 they see these days so there's less of the deep knowledge about these bikes that there used to be, simply because they aren't seen as often any more. I had not considered this particular aspect of owning a very unpopular older bike. 
    9 of 88
    Ian
    5 years ago
    Don't engines that run lean also run hotter?  I could be wrong, but if they do, then that might help explain why it's running hotter now.

    As a really long term plan, if your engine is just too rare, you could consider an eventual engine transplant and get something newer and more common.
    10 of 88
    Yermo
    5 years ago
    Yea, that's exactly what I was thinking. I see it running hotter and thought it must have leaned out the mixture because of better ignition. Unfortunately for me, that hypothesis turned out to be false as the mixture was dead-on what it's supposed to be.

    Interestingly, many of the parts and approaches used on the K100RS match what are done on the same vintage BMW E30 cars (3-series). Yun Lung Yang posited that the coolant temperature sender that feeds temperature info to the ECU is likely bad. Apparently, the ones in the cars have about a 15 year life span and then they get flaky. Symptoms of this are that the engine takes longer to heat up and once it does it tends to run hotter than normal. I found a thread on a K100 site that seems to support this hypothesis.

    So on Friday I'll get a replacement sender and install it to see if that resolves the issue. 

    I can say that the bike is run significantly better in all aspects other than temperature. It's a fun bike again, and it wasn't running badly before at all (with the exception of the occasional cylinder dropping out issue which was the original reason for changing the ICU.)

    As for an engine transplant that's really not feasible. This bike doesn't really have a frame. The engine and transmission make up the bulk of the frame. There's really only a piece bolted to the front that supports the fairing and steering head and a section bolted onto the back for the seat and cowling.

    Realistically I should be able to run the bike for quite a number more years. I suspect I'll run into more electrical and electronics issues since we're getting towards the expected life span of those components. In addition, seals and whatnot will start failing. The rear main seal has started seep leaking, for instance.

    But it's still a great bike for me and I'm no where near ready or willing to exchange it for something else. It's my bike after all. No other bike will do. 
    11 of 88
    Yermo
    5 years ago
    The BMW Part # for the temperature sender is: "13 62 2 242 184".
    12 of 88
    Yermo
    5 years ago
    I put this in the wrong thread previously:

    Link #7288
    Yermo
    5 years ago

    oh dear and now temp issues k100 rs

    ok after the old girl being off the road for so longi did a few 1 of was clean out the fan and grease it . cos it wasent working i then bench tested to make sur

    http://www.k100-forum.com/t829-oh-d...
    13 of 88
    Yermo
    5 years ago
    It looks like the temperature sender cross references to some of the cars.
    14 of 88
    Yermo
    5 years ago
    Driveshaft and spline repair shop that's come highly recommended from endless sources:


     
    15 of 88
    Yermo
    5 years ago
    A video series on lubing splines on a 2V K100RT but most of it applies to the 16V bikes as well. There are six parts to the series.

    Video #8338
    Yermo
    5 years ago

    BMW Service - BMW K100 'Spline Lube' Part 1 of 6

    Make some popcorn, grab a Monster or a Red Bull and a six pack of beer... this is going to be a lengthy journey. How to perform a spline lube on your BMW K75...
     
    16 of 88
    Yermo
    5 years ago
    Rear main seal replacement howto:

     
    17 of 88
    Yermo
    5 years ago
    Professionally rebuilt final drive ordered from Tom Cutter at  
    18 of 88
    Ian
    5 years ago
    That'll put your K bike back on the road, then?  How bad was it when you got it apart?
    19 of 88
    Yermo
    5 years ago
    Ian, bad. Actually much worse than even my most pessimistic expectations:

    Photo #8350
    Yermo
    5 years ago
    More unhappiness
    Photo #8354
    Yermo
    5 years ago
    Broken hard parts.
    Photo #8352
    Yermo
    5 years ago
    Ugh
    Photo #8351
    Yermo
    5 years ago
    That had to hurt.
    20 of 88
    buffalo
    5 years ago
    Wow. Talk about a near nightmare scenario...

    Fortunately, the parts are still available, though what a mess(!).
    21 of 88
    Ian
    5 years ago
    At least you don't have to wonder if the parts REALLY need to be replaced.  :) 

    So I take it just about everything from the engine to the rear wheel needs to be replaced.  What are you getting?  Brand new OEM parts, aftermarket replacements, or a used drivetrain that's been given a once-over?
    22 of 88
    Yermo
    5 years ago
    Long story short, a professionally better-than-stock rebuilt final drive is being delivered for much less than I thought.

    I have a used swing arm on order.

    I'm in discussions with a machine shop in Canada that specializes in remanufacturing these drive shafts to better than stock. I may be able to get one.

    I'm not sure about the transmission but there's a chance it might be ok.
    23 of 88
    Yermo
    5 years ago
    Another source for used k-bike parts:

     
    24 of 88
    Yermo
    5 years ago
    Classic K-bike hints:

    Link #8363
    Yermo
    5 years ago

    Hints and advice for BMW K bike motorcycle owners, K1, K75, K100, K1100

    Includes hints on how to avoid needing a clutch alignment tool, solutions to common problems, etc.

    http://bmwmotorcycletech.info/K-hin...
     
    25 of 88
    Yermo
    5 years ago
    General BMW tech articles written by Anton:

    Link #8365
    Yermo
    5 years ago

    Tech Index

    largiader.com tech article index

    http://www.largiader.com/tech/
     
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