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Offline alexxpotter

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Fuelling/engine "hunting" at slow speeds
« on: August 17, 2017, 11:12:21 AM »
So I was out last night doing an assessment to become an advanced observer (quick plug... become a blood biker, it's awesome!!) and, since I was religiously sticking to 30mph limits (as always, for any lovely police reading this) my XR did not feel that comfortable at 3-4k rpm. I ended up using cruise control to control it but it just felt a little jerky.

Anyone else getting this and any suggestions? Mine's a new Euro4 XR (only a couple of months old, 1k miles on the clock)...

Offline Winger

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Re: Fuelling/engine "hunting" at slow speeds
« Reply #1 on: August 17, 2017, 06:08:46 PM »
There is another thread currently running about the same,I asked the OP of that thread what map he was using but got no reply but I've only found such in Dynamic Pro put  it in dynamic/Road/Rain mine doesn't do it.

I view it as a laymans learning curve about fuelling there's no such thing as a free lunch that it includes fuelling  :002:

Offline Mareng1

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Re: Fuelling/engine "hunting" at slow speeds
« Reply #2 on: August 17, 2017, 06:19:20 PM »
I ran my bike in Dynamic, until I took it out in the rain and thought I would see what if any difference I could see - in Rain mode.  The low rev fuelling was a lot smoother.   Ended up leaving it in Road-mode.   

Could be just that difference?

Offline Winger

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Re: Fuelling/engine "hunting" at slow speeds
« Reply #3 on: August 17, 2017, 06:31:24 PM »
Of course the will be a difference Dynamic Pro is for max HP no good expecting it to bimble through the traffic,hence why in the like of Rain mode it's not only less HP but a more progressive map.

Offline D.C.F.XR

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Re: Fuelling/engine "hunting" at slow speeds
« Reply #4 on: August 17, 2017, 08:37:45 PM »
I also felt that my '16 model was very lumpy to ride at slow speeds as do you. I have the HP Akra end can and thought it may be this so I fitted the standard but it was no better. My solution was to fit a 42T rear sprocket. This had to be made specially by Tallon and cost around £45, it took a few weeks for manufacture but was well worth the wait. The bike is now much smoother through the rev range in all gears and yes it still pulls easily from 40mph in 6th two up, I'm 11 1/2 st and my wife approx 8 1/2 st.
I wasn't aware that the mode setting actually alters the mapping. If you read the owners manual it gave the impression that in rain mode it lessened the throttle response and gave full ABS, Traction control and anti wheelie Road mode as rain but better throttle response and slightly less anti wheelie and so on as you go through the modes

Offline Gatsoburner

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Re: Fuelling/engine "hunting" at slow speeds
« Reply #5 on: August 17, 2017, 10:12:46 PM »
*Originally Posted by Winger [+]
Of course the will be a difference Dynamic Pro is for max HP no good expecting it to bimble through the traffic,hence why in the like of Rain mode it's not only less HP but a more progressive map.

Good as I was going to say
Therapy...

You'll never see a motorbike parked outside a psychiatrists.

Offline Triumphboy

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Re: Fuelling/engine "hunting" at slow speeds
« Reply #6 on: August 18, 2017, 02:03:33 PM »
From my own experience, my bike is also lumpy as described.
A part solution for me was to use the lower grade fuel. This is the first bike I've owned where the 95 RON actually feels smoother than the 98 RON.
I almost always use dynamic mode.
The other thing that made me wonder was the play in the cush drive rubbers. It's something I reported to BMW at the last service but they said it was normal. My view is that the " "snatching" may be exacerbated by the free play.
Might try a set of these to see if that helps.
http://l74trackandrace.co.uk/shop/4591723733/bmw-s1000rr-crush-driver-spacer/10945360?fref=gc

Offline PaulS1000XR

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Re: Fuelling/engine "hunting" at slow speeds
« Reply #7 on: August 18, 2017, 06:43:05 PM »
All XR's have this problem. Blame the EU 3 & 4 emissions regs which dictate a very lean fuel mapping at low power to comply. Their is not really any commercially available satisfactory cure - remapping, Rexer (no remap currently available), power commander etc. none are really a proper fix.  It does get better with miles and you also learn to manage the throttle to minimise the effects. Better to run in Road mode than Dynamic. Don't understand why a lower RON fuel would help?? Don't know why bikes have this problem and cars do not - presumably the same emissions regs apply??
PSH

Offline Winger

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Re: Fuelling/engine "hunting" at slow speeds
« Reply #8 on: August 18, 2017, 07:22:18 PM »
Currently no Rexxer and hence why my Akra headers stay in the box,I haven't tried a PC on my XR but such works very well on my SM XT and my 1100s and has done for years if Rexxer do not come up with a map by the begining of next I'll go the PC route.

Wouldn't know about petrol cars the last one I ran was over 20 years ago and my diesel only revs to 4 and a bit  :002:


Offline JTL

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Re: Fuelling/engine "hunting" at slow speeds
« Reply #9 on: August 23, 2017, 09:18:39 AM »
*Originally Posted by PaulS1000XR [+]
All XR's have this problem. Blame the EU 3 & 4 emissions regs which dictate a very lean fuel mapping at low power to comply. Their is not really any commercially available satisfactory cure - remapping, Rexer (no remap currently available), power commander etc. none are really a proper fix.  It does get better with miles and you also learn to manage the throttle to minimise the effects. Better to run in Road mode than Dynamic. Don't understand why a lower RON fuel would help?? Don't know why bikes have this problem and cars do not - presumably the same emissions regs apply??

I'd give Hilltop Motorcycles a call.  Well worth it for this problem.

 


dysfunctional