Didn't have time to check today, will try to see that tomorrow.
The inside quadrant that the cable turns around should "click" against those Small screws when you open and release the twist grip If they do not the throttle is sticking slightly open and that will screw up your fuel mixture on that cylinder
Have you checked the TPS value The black box on the left side throttle body ?
And Another easy one as Modern Ethanol rich fuel seems to F*ck up components these days If its not fuel hoses dissolving then its Lamda probes
Just disconnect the lamda probe, But make sure the plug or cable cannot melt on the exhaust if it falls down
Look at the diagonal steel pipe on the right side of the bike just by the ECU There is a 2cm round black plug, Just disconnect the two halves
Try one thing at a time so that you know what made a difference If any difference happens
Yes I do have two fuel clamps, tell me about your experiment.
On the upper hose, which is the return to the fuel tank .....
With the motor running start to tighten your clamp until you can hear the pump
strain a little and see if the engine runs better or worse
Do not close the fuel hose entirely or you could pop off a tube inside the tank !
If it runs better you will likely need a new fuel pressure regulator (FPR)
I just had this problem to fix on a very problematic 1150GS Unfortunately some one else had been working on it so I had to verify all their work was correct before diagnosing the problem
It turned out to be the FPR
Sorry I am back to work this last few days after a year off with Post Viral fatigue issues So I am very tired and cannot focus on translating to French 
