K11 Owners Group

[m1ks]

After the previous juggle about i've finally managed to grab an hour of decent weather and time to ride and took the K for a good run this evening.

(105,000 miles on the odometer BTW)

To recap, it was all fine and recently changed the air filter, all OK next ride then swapped the plugs, initially OK, filled up at a different filling station to the norm and on the run home from work started getting a stutter / misfire between 4 and 5k rpm, especially so on rapid acceleration.

Last time out I nipped in the plugs (having already swapped them back for the old uns to see if that was OK, no difference there), a bit tighter, (always been wary of overtightening after stripping out a head years ago and having to have it helicoiled), no real difference after tonights ride, seemed OK to start with shilst warming up then came on once warmed but that could be my subconscious not overrevving the cold engine

Now another possibility has come to mind given that it feels like a misfire, I recall reading of another bike exhibiting similar symptoms which turned out to be one of the coils breaking down under load and causing the misfire.

Does anyone know of any history of this type of problem with BMW or K series machines? Bearing in mind the high mileage of it.

I still have yet to change the fuel filter and check the valve clearances as I suspect that it's been some time since the last full and thorough service, the air filter was pretty mucky but the oil wasn't too bd when I changed that.

Just to note too, it starts, idles and revs cleanly otherwise, I may be hearing a blow on the exhaust in motion but then that may be my paranoia as I can't spot, hear or feel any obvious one when running and stationary.

Sorry for the long waffling post, i'm sort of part rambling and part frustrated about this.
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I will not be pushed, filed, stamped, indexed, briefed, de-briefed or numbered!

[Flying Duck]

1) Make sure the spark plug caps are well seated.

2) Test the resistance of the spark plug wires. They should all be similar.

3) If all of that seems good then it might be the coils. Measure the resistance between the two outputs on each coil - those measurements should be similar as well.
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91 & 92 K75Ss
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IBA #17739 (SS1K, BBG, 50CC)
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[mtnroads]

I agree with Drake - check plug wires and coils. The heat of this engine, combined with 105K has likely caused one or both of those components to go bad.
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2012 R1200RT Midnight Blue
95 K1100LT Graphit (sold)
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[whyoldbill]

My bike exhibited similar symptoms several weeks after I replaced the battery last year. Long story short: Check that you have at least 2 heavy cables running to the ground terminal on your battery.
Somehow I missed reconnecting one and it was making intermittent connections to the frame. It nearly drove me insane until I spotted the loose cable.
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'02 - GL1800


The desired effect is what you get when you improve your interplanetary funksmanship - George Clinton

[Glawseagle]

[m1ks]

Will check the battery but should be OK, was disconnected over winter and charged / topped up, was reconnected and pretty sure I got all the wires, has been on for a good few months but will certainly double check.

I checked the fit and resistance of the leads last plug swap, they were all about 6k ohms if I recall, (will check with the last thread I started on this), and good push fit, have to remove them with the BMW toolkit supplied pliers, will check the coils next chance I get, currently the weather here is lousy and catching a moment of dry to do the work is tricky and the BMW lives outdoors under a cover as theres no room in the shed due to other bikes, (i have another waiting for a base to be laid so I can put it up which it will go into)
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I will not be pushed, filed, stamped, indexed, briefed, de-briefed or numbered!