The Fatal K - flaws - - Excellence in Motion
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post #1 of 37 (permalink) Old Jan 23rd, 2019, 8:06 pm Thread Starter
Join Date: Nov 2010
Location: Selden, ny, USA
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The Fatal K - flaws

Let me share a long standing thought. But first, I bought a very slightly used K 100 RS when it was less than 1 yr old; I hated it! Many years later I 'got a deal' on a K 11 RS and used it for miles, mostly for commuting, and augmented that with a K 75 RT , Istill have that bike and consider it to be my winter bike, largely because of the decent fairing. I am retired now and a few years ago bought a clean, used K 1200 RS, largely based on its looks! Frankly, it does not get used much.

Any way, What can we agree was always the classic K's #1 annoyance, embarrassment ? I would say the damn oil burning! haha, like an old 2 stroke each time you start it after time much on the side stand. Ever wonder why??

Here is my opinion: The R bikes evolved over years and were clearly designed by motorcycle users. The K bike was flawed to start, it was designed by Automobile people! Example' any R bike owner knew that at least some times if the bike were parked on the side stand, it would start with smoke from the left cylinder, the right side never smoked! So some genius says lets make a bike with a car styled engine(fine so far) and lay it so all 4 pots are on the left! What the hell? Imagine if someone (like an R bike rider) reversed the drawings and so the exhaust and head were all on the right side! No smoking on start up, no years of excuses, pinned rings etc that never really solved what could have been prevented on the drawing board.. Oh well.

Next, the early instruments were taken from a 3 series car and put 'out in the weather'. the instruments work ok on a car right? more issues with car thinking, eventually they let the instrument box breath one way with Gore tex.

Excess weight? Look at the knee facing / inner fairing panels on an early K ; made of thick composite like an auto's interior! very HEAVY,

I happen to like my K 12, but it could never be my only bike, I find it too heavy to be 'fun'. I prefer a lighter bike most of the time. like my KTM 990 SMT and 950 ADV. I believe it is the last Beemer to have round analog gauges, a detail I prefer to digital stuff. Pirates Lair sells nice polished aluminum trim rings to go around those BTW. Just my thoughts...
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post #2 of 37 (permalink) Old Jan 23rd, 2019, 8:34 pm Thread Starter
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Location: Selden, ny, USA
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K bike flaw #2

my follow up for every one's consideration;

Vibration! The first 1000 cc bike buzzed badly! No surprise, look around, smaller inline 4 are smooth at below 1000 cc but get buzzy at the i liter mark. In cars, the rubber mounts allow inline 4s to get up to about 2 liters, then they get balance shafts for the larger displacements. Back to bikes we get 3 options, live with it, get a balance shaft, or rubber mount the engine.
For the K 1100 line the foot pegs were on a rubber mounted subassembly so the riders feet were vibe free, the hands still got some though in spite of weighted bar ends. The K 1200 models got a whole new frame and isolated the engine in rubber mounts, that is very effective in squelching the vibes but added weight! A K 12 is substantially more heavy than the K 11 predecessor. (Just like the rubber mounted engine later model Harley Sportsters are about 60 # heavier than the older solid mount models) You need a very strong frame when the engine can not be used as a structural member!

And from left field look at the K 75. Until the 6 cylinder came along the 3 cylinder K 75 was the smoothest modern BMW without a doubt, because from the start it had a balance shaft! (actually weights on the intermediate shaft) Sadly the K 750 engine was never improved over its life. Consider, the K 100 went on to the 16 valve head 'upgrade', then grew 10 % to become the 1100, and then grew again to become 1200 cc. the explanation was there was no room between the cylinders to grow further. What if the 3 cylinder 750 got a 4 valve /cylinder head and grew to around 900 cc? well we would have a bike with an excellent exhaust note and smooth performance as well as less weight. Triumph and Yamaha both sell similar size 3 cylinder models for years. BMW 6 cylinder cars were well loved, to me a 3 cylinder bike is a sweet ride with a similar sound. The K 75 was dropped, supposedly because sales lagged, basically it was low in performance by the mid '90s compared to other 750 cc bikes. As sort of a funny side note to that consider that the original CB 750 Honda was considered to be so fast and smooth when it came out in 1969, the K 75 had highly similar power and weight but a couple decades later it was too slow. I had my 'arm twisted' to ride a dealer's K 1600, for me it is just way too big, but a K 900 RS might have been 'the love of my life'.
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post #3 of 37 (permalink) Old Jan 24th, 2019, 5:13 am
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Shit Bogie, You do know your "Flying Bricks". And from a freakin Long Islander. I went to high school in White Plains but my mom's family was from Free Port. I can remember when there was nothing out the Island but duck farms. I'm a Westerner since the late '60s, now living in Seattle, and can't imagine what it's like to try to ride a bike around in NY these days. I haven't been back since the late '90s when I had to come back to bury my dad. Even in the middle of that major bike boom, on a sunny July Saturday I think I saw only 2 motorcycles going up the Taconic State Parkway. New Yorkers never did take to bikes and law enforcement did not like my go fast, straight pipe CH one bit.

I rode H-Ds for 50 years and only went to an '08 K-40 S in 2011 so I'm still a Beemer student. Your observations clear up a few questions I had about the K-Bike lineage. When I asked franchise shop people what was with the complete redesign of the bike with the transverse engine, nobody had an intelligent answer. One day I did ask why late Brick bikes were so cheap, the kid at the counter just said, "Too fucking heavy". Now I see why; they took a perfectly good stressed engine design and built a huge frame around it just to isolate vibration. That's like deciding you don't like the cables hanging down on the Verrazano Narrows Bridge so you start poring cement under it. They could have balanced the engine and saved the whole integrity of the bike. I do like my bike but we are putting up with 3 complete redirected energy changes. I'm guessing the power loss must be at least 20%.

After the advent of the 1600, I consider the entire K Series as gone; a damn shame too. Once this "Adventure" thing peters out, I'm thinking they might very well close the doors. They have threatened to do that in the recent past as it is and they are making money hand over fist selling cars. the insurance Companies have wanted motorcycles off the road since the '60s. I think they may get their way.

I'd like to hear any other insights you have about K-Bikes. If I were just a little younger I'd probably work up a project bike of my own with a late Brick engine, be damned the vibration. I've done quit a few fast H-Ds and one Knuckle restoration so I'm used to the work. Only trouble is I turn 72 this month. I'll watch for your posts. Good luck with that NY traffic.
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post #4 of 37 (permalink) Old Jan 24th, 2019, 7:28 am
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I have owned a few K series in the 1200 and 1300 variety and still have a K1300S that is my daily rider. Owned several "R" models, however, cannot give up the power of the 1300 which is derived from the F1 engine BMW developed for that series. 1600 is just too big in my opinion and will probably jump to Kawasaki's H2SQ for my next sport tourer unless BMW decides to provide another model similar to the K1300S that I currently ride. Great bikes, cannot say enough good about the experiences this model has provided me over the years.
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post #5 of 37 (permalink) Old Jan 25th, 2019, 3:45 am
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People whine about the K100s and K1100s buzzing but I've owned many and if you keep them properly tuned and SYNCH THE F'N THROTTLE BODIES then they do just fine. I do 14 hour days on mine and they don't buzz at all. No, they're not as smooth as a K75 but a well-balanced triple is going to be smoother than a four cylinder wasted spark system any day of the week.
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post #6 of 37 (permalink) Old Jan 30th, 2019, 7:21 pm
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FWIW, I have had 2 K bikes and can agree that they are heavy. In fact, the '87 K100RT was top heavy enough to be a hazard at parking lot speeds. I didn't experience vibration as you have and never had any smoking after leaving it on the side stand. (My old Bonneville did this a lot, then blew up. Twice). Sold the first K bike because I wanted the '03 K1200GT in its first year. Engine vibration is non-existant, no smoking, and it is much less top heavy. I ran/run the piss out of both bikes, both with over 100K miles. Put me down as a satisfied customer, no real complaints.
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post #7 of 37 (permalink) Old Jan 30th, 2019, 7:27 pm
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Bogie 52: I totally agree with you about the oil burning. I talked about it to my dealer when I first noticed it on my K bike, who explained that it was due to the bike being parked leaning left and suggested that I use a rear stand to have the bike sit upright.
I bought a Wunderlich paddock stand and for a while the problem was fixed but when I started the bike recently, to my dismay the oil burning was back.
I guess the only real solution would be not to park the bike for an extended period of time...
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post #8 of 37 (permalink) Old Jan 30th, 2019, 9:48 pm
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I had my K1200GT in the shop for a ABS problem. This was at a dealer in Mesa Arizona in July. They completed the work the evening the day before I picked it up. So it had been parked on its side standing in 90 plus heat for more than a day. When started the whitish cloud cleared the parking park and exterior sales area. Everyone seemed to find a reason to go inside. It looked like some kind of military training exercise. I laugh about now but it was extremely embarrassing.
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post #9 of 37 (permalink) Old Jan 31st, 2019, 10:33 am
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For the most part, the smoky exhaust on startup is a problem common to nearly all motorcycles and nearly no automobiles because cars do not have separate oil tanks that sit above the level of the motor and most motorcycles do. In a car engine, all the oil is stored in the oil pan under the motor and is cycled to the engine and returned to the oil pan. Every thing remains the same, even over time.

Where as on a motorcycle, the oil is usually stored above the engine in a tank. Over time when sitting, oil leaks past the mechanism intended to retain the oil in the tank i.e. Ball Check or Close tolerance of the pump dive, or what ever. The leaked oil all finds it's way to the lower end where the space is insufficient to hold all of it so it fills to the point that when started, the crank or flywheels as the case may be, picks up so much oil and flings it up into the bores that the rings can't deflect it fast enough so the oil smears past the rings and get's burned in the combustion chamber.

Eventually, the oil pump cycles the excess oil back up to the tank and the smoking stops. The Preferred way to handle the condition is to drain the lower end of the engine hopefully via a drain plug and manually return the oil to the tank. Any time you have oil getting past your rings and burning out the exhaust, you are oil fowling your spark plugs and adding a thick layer of soot to the combustion chamber and valves. All this carbon takes many miles to burn off and actually never does. These deposits build up into a cake that deforms the intended flow pattern of the head and becomes a glowing carbon igniter that sets off the gas charge prematurely causing detonation; a condition that can be rephrased as your fucking motor eating itself alive.

All the situations mentioned by you guys are variations on the same theme. The side stand problem is the same thing but only effecting one side of the motor. The moral of the story is, if you don't start you bike for a month or two, it's a good idea to drain the lower end before starting and pore it back into the oil bag.
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post #10 of 37 (permalink) Old Jan 31st, 2019, 11:09 am
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I guess my K1200GT does not stay still long enough for me to see any problem. Had a K1200S with no smoke just brass parts in the oil filter and a blown trans. Bought a K1600GT man was that bike heavy and traded it for a much older K1200GT (08) and now love riding again. I would buy a new GT today but not going to happen according to BMW. I do not want to buy a non BMW but I know mine will not live for ever. As long as parts can be found I will rebuild.
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