2006 K1200S Stranded me; diagnosis questions.

UPDATED! 2006 K1200S Stranded me; diagnosis questions.

UPDATE post below dated 8.2.18, short version of which is it appears I have the old 2d gear transmission dog issue, piggybacked onto the fueling issue which I now fixed.

Yes, if you're all over the K forums, I've posted this elsewhere, but without luck. I paid to join this forum, because from looking around it seems ya'll are the smartest and most helpful bunch around, flattery, flattery, etc., etc.

I'm afraid this will be the equivalent of Murphy's law 201(A)(3)(b): A broken object will work perfectly when demonstrated for the repairman.

My K12S is fairly new to me, but have put a couple tanks through it with no issues until Saturday on a ride way out in the TN twisties. Started noticing slight, quick off/on surge (like throwing light switch on and off) in gears 3-5 at about 6-7k rpm. Ride on 15 miles, and it’s now in all gears and at nearly all rpm and getting worse. Bike dies the first time headed up the side of a mountain on switchbacks. Get it restarted several times and to top of mountain. Figure it might be one of the heat-related issues with this model bike, since it’s the hottest and most humid day I’ve had the bike out yet (although just high 80s at this point, but climbing). Wait 15-20 min. Still won’t start for more than a few seconds. Slowly coast 9 miles back down mountain (no servo issues with my bike at least, since I lived through the experience). Stop and start with at least 5 min. wait at least 10 more times, including having to push the bike out of several intersections (decided to go back home through civilization, in case I got in real trouble). Despite the ambient heat, however, water temp never gets any hotter than I've had it up to previously, which is 3 bars above the bottom line, or smack dab in the middle of the temp gauge. Turning the starter on and off makes no difference, either. Finally, battery dies, and that's it. Call for help.

Possibly relevant info? BMW newer hydraulic cam chain tensioner installed (Abe Lincoln stovepipe hat). BoosterPlug installed (and routed to a suggested location, next to the right air snorkel; I never had the extent of stalling or surging or idling noise or other throttle issues some did, but put it on anyway. To be honest, never noticed any difference, better or worse, since installing it). Hottest and most humid day bike ridden so far, as mentioned above, and problem got worse as day got hotter. Only things done since last ride: top off with no ethanol gas, and throw in a can of the much beloved Liqui-Moly 4T racing fuel additive. In case one of those was the issue, I stopped at a gas station on the way back, and topped off again to dilute any ill effects of either the newer gas or additive, but it just kept getting worse. Dash never showed a code, until the engine actually stopped running, at which time I got the dreaded red triangle (well, thanks, bike; I kinda noticed you quit running!).

The way the engine was behaving, no way an injector was clogged, or spark plug had come loose. It feels like any spark and/or fueling issues were coming from the computer/electrics, not anything mechanical.

On Sunday, went down to the garage and...after Opti-mate back on all night and battery recovery, she started right up at first touch. Only abnormal thing was for less than a second, the cam chain sounded louder than I've ever heard it, before the fluid got in the tensioner (not merely loud, but like rocks-in-the-case loud), but went away a split second later and never returned. That part made me wonder if all that dropping it into 1st while revving the engine to try to keep it from dying on Saturday may have stretched out the cam chain somehow. I let her run, repeatedly rolled on and off the throttle, dropped her into 1st gear and revved it with the clutch in, held it at 4k for an extended period of time with no fueling glitches, and heated the water up to the same temp as when it just wouldn't go any further Saturday, and of course, everything ran just fine. Into what malfunctioning electronic sensor hell have I fallen? Oh, well, I suppose I'm far too old to have never experienced the shame of a running H-D'er riding past me as I push my BMW out of an intersection, so the motorcycle gods punished me for my insolence.

I do a lot of riding alone, and I'm now afraid to ride it more than walking distance away from home. Any help anyone can give me on a diagnosis plan decision tree, simplest to less so? Something easy I was too dumb to consider?

I think you have water in the gas. Add a bottle of Isoheet in the red bottle and see what happens.

It's not an exact match for a problem I had with a bike, but you could be losing fuel pressure due to a bad pump. Has there been a recall pump replacement for that bike? With an F800 I worked on, it took an hour or two for the problem to show up and then it would stall when I rolled off the throttle. After a while it happened several times per mile. When these engines run out of fuel there is no sputtering... they stop like you hit the kill switch.

AntonLargiader said:

It's not an exact match for a problem I had with a bike, but you could be losing fuel pressure due to a bad pump. Has there been a recall pump replacement for that bike? With an F800 I worked on, it took an hour or two for the problem to show up and then it would stall when I rolled off the throttle. After a while it happened several times per mile. When these engines run out of fuel there is no sputtering... they stop like you hit the kill switch.

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First, to answer your question: Yes, my bike was subject to the recall, and BMW says the recall work was done, but as you probably know, the recall was for leaks, and they were only supposed to replace or fix the flange, and only inspect, and then replace the pump and/or associated fittings, IF it needed it. My large ring flange was replaced; I could see the newer metal ring around the pump when I took off the tank for the BoosterPlug install, at which time the aged and brittle plastic fuel line (plastic? really, BMW?) male fitting broke, so I replaced it with the metal fitting set from beemer boneyard (HIGHLY recommend anyone without a metal fitting set just go ahead and replace them). Interestingly, BMW also did a fix on the female fuel line fitting into the pump with a metal ring reinforcement (their own, not the beemer boneyard version), but left the cheap plastic male fitting on there, when they replaced the pump flange. I have no idea if they replaced the pump at that time, but if it's bad, I suspect not, since this recall came about in 2014, IIRC.

Replacing the pump is a bit of a frightening thought (just ordered the GS-911wifi with extension cable so you can use it while riding, and maybe should have spent the same roughly $500 on a fuel pump assembly), but not really unexpected, although I was suspecting an electronic gremlin telling the pump to shut on and off. Oh, well, I suppose I'll use the diagnostic tool over time, anyway.

The most frustrating thing, if it's the pump, is that I have a lot of BMW "special" tools, or copies of them sold by others, but there's no way I can replace the big metal ring to get a new fuel pump on myself, and so will have to *gulp* go to the dealer.

It does raise another question, though. Since it was a bike you were working on, did you have the diagnostic tool, and did it throw a code? If so, what was the code?

AntonLargiader said:

It's not an exact match for a problem I had with a bike, but you could be losing fuel pressure due to a bad pump. Has there been a recall pump replacement for that bike? With an F800 I worked on, it took an hour or two for the problem to show up and then it would stall when I rolled off the throttle. After a while it happened several times per mile. When these engines run out of fuel there is no sputtering... they stop like you hit the kill switch.

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That would be my guess, too.

Good luck with it and let us know what the final result is.

If you got a new flange then you got a new pump.

No codes in my case; the pump was seizing when hot which doesn't throw a code. If the controller had been shorted or open it probably would have, but the pump is past the controller and not diagnostically visible.

I found it the old fashioned way: hypothesized that I was losing fuel pressure, put a pressure gauge on the bike, rode it for a LONG day ride and eventually observed the stalling and the fuel pressure loss. It's a pain when problems take so long to reappear but the owner had been nearly stranded by it several times and I needed to get to the bottom of it.

AntonLargiader said:

If you got a new flange then you got a new pump.

No codes in my case; the pump was seizing when hot which doesn't throw a code. If the controller had been shorted or open it probably would have, but the pump is past the controller and not diagnostically visible.

I found it the old fashioned way: hypothesized that I was losing fuel pressure, put a pressure gauge on the bike, rode it for a LONG day ride and eventually observed the stalling and the fuel pressure loss. It's a pain when problems take so long to reappear but the owner had been nearly stranded by it several times and I needed to get to the bottom of it.

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Oh, the irony if a new fuel pump is the problem. If it's their new part, maybe I can get a discount on a new one from BMW. But I joke.

When into my ride after the problem appeared, once able to get it restarted, the fueling on/off made the bike like a bucking bronco, and would have probably made me wreck if I was a newbie rider.

In all seriousness, God bless you for being willing to get to the bottom of it for the owner, too. I've heard problems like this forcing someone to just get rid of the bike, because they'd take it to the dealer, who refused to do anything because the bike wasn't throwing a code, and nothing else was obviously wrong, and they couldn't replicate the problem.

I don't have a fuel pressure tester, but know they're cheap and easy to use, so it's a good investment for me regardless, but I've heard some Bosch systems on some BMW bikes need a version with a special coupler. Any idea how to find out if my bike needs it, or if a regular pressure tester will get the job done?

If mine doesn't throw a code, I'm going to see if I can talk my wife into following me with the truck and trailer to the nearest dealer 1.5 hr. away from me. Hopefully, by the time I'm there, my bike will be malfunctioning.

Upon further review, I've spoken with more people who agree it's the fuel pump. It's just a simple 37mm pump, and many inexpensive, reliable alternatives to the OEM pump seem to be available. Further, since the pumps are what seems to go bad, I'd rather just replace it first and only go into the rest of the assembly parts if necessary.

I'm able to make this repair myself, if I can just get the tool you use to remove and tighten the big metal ring that attaches the whole fuel pump assembly to the gas tank. Anyone know the BMW part number for the tool? I'd rather pay them for that than the pump, and then have the tool for future use. If no special tool is necessary to take the ring off and put it on, exactly how do you do it?

Found the answer to my own question as to the tool. Same as for BMW cars of same vintage: https://www.ecstuning.com/b-assembl...MI69Olu7Lg2wIVwwOGCh16rQGgEAQYAiABEgLZyfD_BwE

Why not use a piece of wood, or a punch and a hammer instead of that expensive tool?

mattias_k1300 said:

Why not use a piece of wood, or a punch and a hammer instead of that expensive tool?

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That's a fair question:

1. As it relates to this particular situation, the whole front of the fuel tank/pump area and all attachments on this design have proven to be particularly fragile, and I don't want to tear anything up. Initially, BMW used plastic fittings for the fuel hose, and both male and female sides had issues with cracking; then, we have a lot of reports of pump failure. If you do screw up either the front of the housing for the pump with the electrics, or the tank itself, you're out more money than for just the pump, and in the case of the tank itself, is over $1k if you can't find one at salvage.

2. A punch (and as someone who likes to do his own gunsmithing as a hobby, I have a TON of punches), block of wood or the like only puts pressure at one of the many contact points, and concentrates all the force you bring to bear at one spot, whereas you can safely apply much more force without bending any of the contact points on the ring with the tool, which spreads out the same forces.

3. Just personally, and ONLY speaking for myself, I grew up poor, and my father and I had to jury rig and be "creative" on the farm to try to fix stuff breaking down all the time, because he couldn't afford the proper tools, and I saw many of those attempts just lead to tearing up what we were trying to fix. To be fair, some wealthy folks choose to do that, too, but even though I certainly don't consider myself wealthy, I promised myself a long time ago that if there were a specific tool made to do something I need to do, I'd buy it, if I could afford it. Sometimes, it worked without expense, too, and made us feel brilliant, but there was always that worry of boogering it up, which happened more often than I'd like. As always, YMMV.

i am a big fan of right tool for the job also...but..

for fuel tank nuts like this, which are similar to generations of the ones on bmw cars, i use two long flat blade screwdrivers. hook blade ends behind opposite contact points, cross shafts of drivers in middle, and twist. ez. spreads load. no issues.

not as cool looking as the ECS tool though...

mlytle said:

i am a big fan of right tool for the job also...but..

for fuel tank nuts like this, which are similar to generations of the ones on bmw cars, i use two long flat blade screwdrivers. hook blade ends behind opposite contact points, cross shafts of drivers in middle, and twist. ez. spreads load. no issues.

not as cool looking as the ECS tool though...

Click to expand...

Now this, I like, but the nut on my bike is on TIGHT. I did some testing on how tightly it was on when I had the tank off to install the booster plug and fuel line fittings, but I couldn't get that thing to budge by tapping with various items (of course, I didn't want to tap very heavily, to avoid damage). I may try exactly what you suggest before using the tool, and see if it works for me...or if I need to spend more time in the free weight room at my gym.

One more related question for those of you who are familiar with the ring setup: Should I replace the gasket with a new one when I remove the ring to replace my fuel pump, or am I good to keep the old one if it's undamaged?

I've learned BMW always wants you to install a new o-ring or new gasket every time you unscrew anything or take it apart, but unless it's like having to buy those "torque only once" bolts for the crankcase, I don't see buying a new gasket if the old one is in good condition. Ya'll's thoughts?

Bit of an update. The GS-911 pretty much says it IS the fuel pump. It coded over 20 failures on my last ride. The electric controllers were showing only 2 failures, and of note, I've had the tank off twice, and thus the electrics unplugged twice, once to install the BoosterPlug, and the other to replace the fuel line fittings when the plastic garbage OEM ones failed.

Just ordered a fuel pump (based on some recommendations, got the EnduraLast, which appears to be a MotoElectrics store copy of the Bosch). They can be found for anywhere from $40 for some cheap-looking ones, up to the BMW one, which is over $400!

Won't be able to do install until a week from this weekend, but will update then on how things go.

Thanks again for everyone's kind help!

UPDATE! 83.33% Fixed; what...the...fudge?!

Installed new fuel pump. Just came back from a many hour ride in 88-89 degree heat with only one stop for gas. An hour in, ONLY 2d gear developed a quick, off-on hesitation which never happened at high rpm when accelerating to go up through the gears, but did it a lot otherwise. It never showed a desire to quit, however; just the sensation someone had flicked the light switch off and back on in less than a second. And despite attempts to get it to replicate in other gears, travelling for 10-15 minutes straight in 1st and 3rd and 4th gears, never could get it to replicate.

Wut the flip do I try next, guys? This was with a brand new, not rebuilt, fuel pump, and common sense tells me that if it were failing, it wouldn't fail in one gear and not in the others. I had even considered that maybe I got a bad batch of the Luqui-Moly additive which harmed my fuel pump, but it wouldn't just prevent it from working in second gear. And the same is true if water had gotten in the gas. I did install the Booster Placebo, er, plug, but how could it cause this? And an ECU can't "fail" in this manner, can it?

I'll see what codes, if any, it threw tonight after cleaning it thoroughly. Car hit a dead deer carcass bloated with gas in front of me, popped it like a balloon, and sprayed me and my bike all over.

But hey, it was a pretty day to take a ride out through the country, and this time, ol' Brunnhilde didn't strand me.

As always, thanks for any help/suggestions.

EDIT: If this continues, how about the electrics to the pump itself? Can they do screwy, gremlin-like things which would affect different pumps, but in different ways?

dobervol said:

...just the sensation someone had flicked the light switch off and back on in less than a second. ......

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Leads me to believe you have an electrical, not a fuel, issue. But heck, I'm as puzzled as you.

I half want to say check your sidestand switch or the wiring from your ignition switch or the engine shut off on the handlebar switch.

...and my gremlins get more interesting. Ambient temp. DOES affect what's going on. More trips with the new fuel pump, and while the problem is still limited to 2d gear, it totally disappears when the temp. goes down to the low 80s. While the bike has not thrown a code for it since the new pump was installed, I've ordered the electric fuel pump controller, BMW part #16 14 8 523 262, and will be installing.

It did throw 2 codes when my bike just quit, and failure of the electric unit is acutally a more common problem than I realized, from searching innerwebs. The same part covers many years and many different models, and the theory is that the fins on the thing are an insufficient heat sink for cooling the unit, as the location of the unit, on the front of the gas tank, shielded from air flow, would make ambient temperature matter, since it is in effect air-cooled. This would also mean that those in warmer climes are more likely to experience a failure.

Accordingly, because it can fail suddenly and catastrophically, leading to "won't start and won't run," a pretty big problem, I'm replacing the thing, and also am buying an emergency temporary bypass cable to power the fuel pump directly from the battery from burnsmoto, as well as never leaving home without the tools to allow me to remove the gas tank. Most tool kits will include the T25 bit or wrench, but most will NOT include the big hex bit necessary to remove the narrow end of the tank under the seat.

Will update everyone after next install (removed tank once for BoosterPlug install, a second time for fuel line hardware replacement after plastic stock fittings cracked, a third for the new fuel pump, and now this will be the fourth!) and after I've ridden in 90 degree weather, since the problem only seems to appear from high 80s upward.

Normally I wouldn't post all this, but I'm hoping that my tale of woe might save a fellow rider some misery in the future.

If the original controller module is silver, yeah a fail potential, the newer units are anodized and black.

henzilla said:

If the original controller module is silver, yeah a fail potential, the newer units are anodized and black.

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Mine is black, but anodizing only stopped the problem of failure due to corrosion; they didn't make the cooling fins larger, from what I can tell. With my unit throwing 2 codes, I'd rather be safe than sorry. Of course, if I replace it and the wierd 2d gear issue persists, I'll report that as well, but at that point, I'd be running out of things to replace/fix.