General topics » Weird lurching/stuttering...hard to describe...

Good afternoon chaps.
So I’ve now done about 1400miles on my 2018 RS. General loving it....but I’m detecting a weird sensation whilst on a steady throttle - a sense of repeated, small repeated ‘lurching’ movements. Very small. Almost undetectable. But it’s there. I’ve found some VERY smooth roads to ensue that this is not just caused by road imperfections. I thought it might actually be the damping/suspension but it doesn’t seem to change no matter what setting I use or what road surface. The bike just does not feel as smooth as it should. Am I going mad? I think it disappears when accelerating...and is maybe even more noticeable when decelerating on a closed throttle - it’s feels ‘choppy’. My S1000R is sublime to ride compared with the RS now I’ve noticed this (if much louder)?!!
Could it be the traction control playing up - doing something weird? Anyone else had this odd feeling??
Sorry - as I said it’s hard to describe. I’ll probably book it in to dealer soon to have it checked. Maybe something needs resetting or recalibration? I’m just not sure what?!
Thanks for any thoughts or ideas..
Cheers
TB

It sounds like a lean mixture issue. It could be a faulty injector or fuel pump. I would get it checked out by a dealer asap.

te=06423RS|p3337]Good afternoon chaps.
So I’ve now done about 1400miles on my 2018 RS. General loving it....but I’m detecting a weird sensation whilst on a steady throttle - a sense of repeated, small repeated ‘lurching’ movements. Very small. Almost undetectable. But it’s there. I’ve found some VERY smooth roads to ensue that this is not just caused by road imperfections. I thought it might actually be the damping/suspension but it doesn’t seem to change no matter what setting I use or what road surface. The bike just does not feel as smooth as it should. Am I going mad? I think it disappears when accelerating...and is maybe even more noticeable when decelerating on a closed throttle - it’s feels ‘choppy’. My S1000R is sublime to ride compared with the RS now I’ve noticed this (if much louder)?!!
Could it be the traction control playing up - doing something weird? Anyone else had this odd feeling??
Sorry - as I said it’s hard to describe. I’ll probably book it in to dealer soon to have it checked. Maybe something needs resetting or recalibration? I’m just not sure what?!
Thanks for any thoughts or ideas..
Cheers
TB[/quote]

Do you have cruise on your rs ?

Ged

Have you ridden throttle by wire bikes before?

That sounds like a typical BMW lean surge operation. Their bikes have been doing that sort of thing, off and on, since at least 1990. Things were really bad on my 1991 K100RS until I replaced the FI computer with an aftermarket performance one. Then the lean surge became exceedingly irritating around the turn of the millennium, but it was finally brought under control around 2004 when BMW added a second spark plug to their oil head models. I don't notice any surging on my RS and when I rode my friend's R1200GS. However, perhaps Euro 4 has brought back some of that lean running again.

Are you riding in dynamic mode? I've found lurching, especially at slower speeds, to be much more noticeable. Switching to other modes solved that issue for me. Try that and see if it works for you as well.

Hey guys
Thanks for replies.
Yes the bike has cruise control - but never used it and never will. Could that be a factor?
I’ve ridden recent GS-WC and have S1R - previously had K1300S, 1200GS, 1150Gs and Boxer Cup Replika (plus many Triumphs and other bikes). Never experienced anything like this before.
I’ll try to get it to dealer in the next week - hopefully I’ll be better at describing it to them!
Cheers
TB

Sorry. Missed this.
I have tried Road mode (is that what it’s called?) - but i’ll try it again now you’ve mentioned it helped solve you issue. Many thanks!.
TB

Zitat von 06423RS im Beitrag #7

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Hey guys
Yes the bike has cruise control - but never used it and never will. Could that be a factor?

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I found that when I first started using dynamic engine mode, so I switched it off, a couple of years later I switched it back in, and no more lurching/faltering.

I now get what other guys have said about dynamic mode, it is the best mode to be in, but I suspect it needs a decent running in time to get real smooth

Again - thanks guys. This is helpful.
I’ll switch back to Road mode for a while and see if it changes anything.
Cheers
TB

I'm, possibly, a non-typical owner, but I ride in Road mode and it still took me a long time to adjust to the sensitivity of the "throttle by wire". As background, this is my first bike with this type of throttle. The cruise control did eliminate the unsteady throttle, but I'm not a fan of the disengagement experience.

In any event, a few months after purchase, I installed a Wunderlich bar-end throttle screw which provided some throttle resistance. With time, I've adjusted the sensitivity of the "throttle-by-wire" and the continual resistance is not necessary. However, I still prefer using the throttle screw for cruise control when dealing with traffic on 4-lane highways.


However, during this period of ownership, I've never experienced anything I would describe as lurching or stuttering. Certainly, nothing like the "surging" of the oilheads.

Sounds like the throttle bodies are out of adjustment. Get your tech to balance the throttle bodies and up the fuel trim a bit.

I have it. Always has. When rolling along steady with little engine load.

Been all around about it. I have a theory.

They are quieter and smoother than the older ones, with computer controlled gizmos, this brought to light another engineering factor.

I think it is a gear synchronization or harmonic.