Winterising the 1000s today, dropped the float bowl’s to drain them (and spray some wd40 on the inside bit’s), found a strange black residue in both bowls, 
,
Fuel clean coming out of the tank, looks like the dreaded ethanol is degrading the fuel lines, new lines+ss clips ordered
My experience has been that whenever you leave the float chambers long enough to dry out, it leaves a nasty residue behind. This builds up over time to make a horrible hard deposit over the interior. I’ve had blocked up jets, others have had floats getting caked up and sticking against the walls. My deposits tended to be green or brown in colour. It got so that I really needed to drain the float chambers if bike was not going to be used if for only a week or so, if I didn’t want reccurences.
I’m not sure it’s just because of the ethanol content though - as I have a habit of saying, modern petrol is not made for carburettors any more, becasue things like what happens when it evaporates are not relevant to a sealed injection system.
Just IMHO.
Not saying yours colour doen’t mean hoses disintegrating, could be too. For a long time I made sure to get Viton hose, which I’d been doing since probably the mid 2000’s, if not maybe earlier.
Viton hose on order,
(bike had only stood a month), point taken on modern fuel
Cheers Phil