2001 R1150GS cutting out

Hi everyone!
My R1150GS is sort of cutting out momentarily while cruising at about 3800 to 4200 rpm.
Sometimes it's so bad it makes the bike "jerk".
In higher revs it seems to be less evident, but the vibration hints that there's still a problem.
It's worse when the bike is fully warmed up. When it's cold it goes smoother.
The problem is more evident in top gear.
I have relatively new coil, HT leads, spark plugs, 1200 matched injectors, y-pipe AF-XiED and stage 11 John Gemi chip. TBs balanced, TPS adjusted for the correct voltage.
Ignition switch harness was replaced about 20,000 kms ago.
All fuel lines were replaced about 10,000 oms ago while replacing the fuel filter and the pump strainer.
What could be the problem?is it electrical or fuel related?
Thanks

You didn’t say which year your GS is but I’m assuming it’s single spark (pre-2004 MY).

The single spark were known for surging slightly below that rpm range — usually 3300 up to 4K. This would be a definite “surge” versus “cutting out” though. (The dual spark effectively eliminated this issue). It appears that you have all the common fixes already installed. Not sure about the Gemi chip in combo with the AF-Xied. How long has your bike been equipped as described before the symptoms appeared?

Yes Paul, it's 2001 single spark.
Actually, before I installed all the addons, it ran worse. It's running much better than before in general, which helped me isolate the issue in question.
It does feel a bit like the known KFR issue, but the latter usually appeared in lower revs and was eliminated by the y-pipe+Brisk plugs combo.
The y-pipe and the chip are the oldest adds, they are about 30k kms old. The rest was installed within 7,000 kms ago.
The only part I didn't get to check or replace was the hall sensor. I'm waiting for the test tool for that to arrive.

There's another thing that may be related.
My TB's BBS are set in the way that the right one ia about 1 turn from fully in and the left one is just about 1/5 turn from fully in. That's the only setting I could get them synced at normal idle speed.
They were taken out and cleaned before the syncing.

Check that all your fuses and relays are fully seated.

Watch the tach as it cuts out. If it bounces erratically that indicates a HES problem.

Jim, I did watch the tach and it doesn't bounce when the problem occurs or ever.
All fuses and relays seem to be seated properly.

does the RID flash on and off when it happens? that's an indicator of a bad wire to the ignition or kill switch.

No, the RID doesn't flash and the ignition switch harness is pretty new.

Does it still have to O2 sensor? If I might try unplugging that. The connector is under the tank on the right side.

Yes I still have it, with AF-XiED installed. I never heard getting rid of it ever solved anything, do you have any specific info on that?
BTW, the O2 sensor was replaced about 25K kms ago.

I had an O2 connector that had water intrusion. When it rained the bike would cut out at steady speed. If I accelerated out of it the bike would "fix" itself because the O2 sensor is taken out of the loop during brisk acceleration.

This is an interesting observation, but it didn't rain here for more than 2 months.

KFR = surging

is it surging or cutting out?

If the Y-pipe and chip eliminated the KFR issue then why did you keep making changes? Were there other issues?

When I’m trying to solve a problem I try to make one change at a time so that once the issue is resolved I know exactly what in the process created the solution. And I can identify the appearance of any new issues.

我01激增问题。我做了Y-pipe and 1200 injectors and then an Iice-Air module. That seemed to solve the problem but many have suggested the ice-air is snake oil. And it very well may be. As the surging would subtly reappear occasionally but much less pronounced. Before selling that bike I returned it to stock configuration and was reminded of the surging ;-)

I now have an 02 GSA which has never exhibited the surging. I have installed the 1200 injectors, Y-pipe, AF-xied and Lenny’s sprockets. Still no surging. ;-)

My concern is that the Gemi chip and AF-xied may be in “conflict” with each other. They kinda do the same thing differently. Have you tested different settings on the AF-xied? What do you currently have it set at? I don’t think the Gemi chip has any user adjustments?

Yeah, but it could just be a bad wire.

Paul, I stand corrected, it's not surging, it's cutting out intermittently. If it wasn't a fuel injected bike I would immediately suspect an electrical problem.

I kept doing changes because bike was running Iike sh.t and vibrating like crazy.

The only thing I was too late to check was the TPS which was off. When I got it right, it improved throttle response like night and day.

As I said, the problem in question seems to be the only one left from what was generally a mess of a bike I bought at 240,000 kms. Did a top end rebuild at 267,000 kms.
It's at 283,000 kms now.

I gave a thought about the AF-XIED/Chip combo, but from what I read, they deal with different circuits - the AF-XiED only affects O2 sensor readings.
I also heard that the chip does not "attend" for idle and small angle throttle openings which are governed solely by the O2 sensor readings.

Well, maybe disconnecting it just for a test ride could be a good idea, just to see if that specific problem is gone. I will also double check the splicing I did to install the AF-XiED.

我骑数万英里O2sensor disconnected. IMO it actually runs better.

The plot thickens...;-)

a couple of things. Isn’t your issue occurring right where the transition from AF-Xied to the chip?

Also, the large variation in the BBS is a concern. How do the TB’s sync off-idle? I would be more concerned with them synced off-idle compared to idle.

Paul, the plot was pretty thick to begin with)))

It's an interesting thought about the AF-XiED - chip transition point. As Jim suggested, I will disconnect the O2 sensor to see if that cutting-out goes away. If that will be the case, I will first look at the connections and then try different AF-XiED settings.

Actually I installed AF-XiED to solve a problem that later turned out to be TPS out of adjustment. I was just afraid to fiddle with TPS... until I wasn't)))

The TBs sync pretty well off idle, but I do find it a bit hard to get consistent readings. Maybe my Carbtune tool is not accurate enough.

Yes, the variation between BBSs is weird, but this is really the only setting that got me a balanced Idle. There's another strange thing - if I turn the r/h bbs fully in - the engine starts to die. If I turn the l/h bbs fully in - it may sound unbalanced, but keeps running. I thought there was an air leak, but spraying carb spray in the usually suspected locations did not affect anything.
I heard suggestions that the TB shafts may be worn, which could cause an air leak too, but I'm still a bit hesitant going these places.

And how was your fuel mileage?