The old fuel left in my FJ's carbs turned bright luminous green and also turned into sticky goop - I had to pull the carbs off, clean out all of the jets and passageways and the chambers, it was a pig of a job, but the bike wouldn't run properly until I'd done that.
Yes, modern petrols are less "petrol" than ever and are really sensitive to storage time. Personally, now, if I'm going to store the bike (or leave it for a while), i fill the tank with Super, add a bottle of Wurth fuel stabiliser and then run the bike for about 15-20 mins (about 20 miles), to make sure the stabiliser is mixed in and circulating all around the fuel system before the bike is prepped for storage.
No more problems !