Here we go....

[Bixxer Bob]

Bike's been standing for about a year, but started after a couple of cranks on a good battery and full choke, needed a squeeze of throttle to keep it running, but died the moment the throttle was opened regardless of how gently I coaxed it. 

What could POSSIBLY be wrong 

[London_Phil]

Every time I leave my bike for more than a week, and sometimes even then, it runs like a dog, and wont run unless chock is out and im ticking over at 2.5K!!
Run it up the road, carefully, and without fail within 5-15 miles ( or by Hemel Hempstead if your near!!) it will be running again.
It has to be fuel contamination of the jets.
I changed plugs,carbs (from Mikuni to Keihin), coils (TT600),ignitor,ECU, fuel type , etc etc, and always the same
I strongly suggest that unless you have a penchant for stripping it down, it needs a damn good  thrash...IMHO of course.

[nickjtc]

I strongly suggest that unless you have a penchant for stripping it down, it needs a damn good  thrash...IMHO of course.

+ a can of Seafoam or similar in a full (fresh) tank of fuel to help it on its way......

[Bixxer Bob]

Post was a bit tongue-in-cheek,  it's my old Plastic Maggot demonstrating classic crap fuel issues, just like a Steamer.  Half a bottle of fuel treatment and a gallon of new fuel got it going-ish.  It's still coughing and farting a bit but runs enough to take it out for a thrashing.  Just got to get it MOTd first.