2006 K1200S Stranded me; diagnosis questions.

[henzilla]

The only does this in second gear is a scratcher for sure.

Another fine re-engineered item in the fuel supply of this model is the airbox and idle control valve screwed to it. The new box had a lot larger opening and larger idle control valve with tubes running to throttle bodies. I have pictures of both, but on a different computer.


Seems GT's were more prone to a warped airbox...may be the dual air inlets of the S didn't allow the box to warp as badly. Anyways, caused a stall issue more often after a long run. I replaced two on early K12GT's. Neither of our two S's presented that issue.

The stick coils will not show as a failed unit, so pretty much need to either replace all four or narrow down a bad one, which on that model is a PITA compared to a Boxer. The FPC on the R12XX's sat in a well on top of the tank and they corroded,leaked and failed. The location on the K at least has it vertical, so the failure rate is lower.
Never concerned with heat, but we avoided anyplace that the air was not moving if possible on these models
Hope you narrow it down

 

[dobervol]

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.

Welp, my memory is failing me as I age, and to keep this totally accurate so as to be of help to others, I'm pointing out an error I made. Replaced the electronic fuel pump sending unit last night, and the one I was replacing was NOT black. It had no corrosion on it whatsoever, BUT is was matte silver just like the early ones. Will update after going for a ride to see if it fixed the strange 2d gear fuel cut-off issue. As henzilla reported, this oddly enough makes me a tiny bit more optimistic that this will solve the issue once and forever.

After joining, got this month's issue of BMW ON, and the Wes Fleming "Torque of the Matter" tech article is scary as heck, as he, too (although on a GS), had an electronic gremlin issue on a bike of similar age, and wound up basically having to skip up through 5th gear to avoid just replacing the whole frikking computer at a cost of $1,200.00. Skipping 5th is a lot easier to do than 2d, so I'd be stuck with ponying up, most likely. Fingers crossed.

 

[dobervol]

No change; another $150.00 down the drain.

Replaced the electric fuel pump controller for about $150, and still doing exactly the same thing, although had to get to the point of the ride where the engine was hot and needed to use 2d for an extended period going up a hill. I had optimistically thought I'd fixed it before then, so hadn't put in 2d to check for an extended time. Stops and starts with 2d gear gearing are almost enough to buck you off, but still only 2d gear. New fuel pump fixed the stalling issue in all other gears but 2d, but the new controller did nothing one way or the other.

Something, somewhere, for some unknown reason, is "telling" that new fuel pump to shut down like that, but if that something is the ECU, I'm not sure what I'll do. That's an absurd expense, and now I can't easily get rid of the bike with this issue, because I'd disclose it fully to a purchaser, and you just can't do without 2d gear very easily.

The GS-911's lawyers hedged in the scan language, and said the two non-pump fuel system codes it threw before I replaced the pump (no relevant codes on the 911 since then) were "probably," "most likely," or some such wording, due to the electric fuel pump controller. I suppose I'll have to give up and take it to the dealer at this point, and hope the actual BMW tool tells them what it is, AND that it's not the ECU.

If anyone hears anything of the kind at any summer get togethers, please pass it along. Thanks, all.

 

[dobervol]

I'm embarrassed the subtle difference did not strike me as relevant, as the power appeared to my ears and senses to be completely cut from the ENGINE, but it would appear that my ECU is NOT throwing any codes and is fine, and the diagnosis for what's wrong with 2d gear is, well, 2d gear, or more specifically, the dogs engaging it, on my 1st gen trans unit with pre-8/06 mfg. date.

The issue, with the dogs breaking loose under heavy load, such as going up a steep mountain in second gear while accelerating, and under strong acceleration from a shift from 1st, mimicked the bucking feel of the defective fuel pump cutting out and back in. I didn't know about the trans issue with the K12S, and had thought a trans issue would be noisier and more catastrophic with metal about the whole unit, but it does indeed feel like the dogs doing a 45 to 90 degree turn, then catching, slipping out again, and so on.

I'll confirm once the tranny is pulled, but have posted with more detail over in the K-bikes forum, as many folks at the time back in 06 and 07 when these problems first appeared posted over there, and indeed people here recommended they go over there to discuss the issue.