Okay, I'm out of ideas so I need some outside of the box thinking...
I got my bike back from 12,000 mile service - oil change, new plugs, air filter, carb balance and valve job. Bike ran better than every at high RPM, but after warming up to operating tempurature "sometimes" (often but not always) it will die when I pull up to a stoplight. No stumbling, just cuts out but then is always able to fire right back up.
I tried raising my idle speed. Same symptoms.
I checked my airbox for leaks and all electrical connections. All electical connections were good and I tightened the hose clamps between the airbox and carbs and carbs and the engine. Same symptoms.
I pulled the tank and looked for vaccuum leaks. I have a CA bike so I disconnected all the emissions stuff and put balancing hoses between the carbs and intake manifolds. Same symptoms.
I bought a D-tool from Brent and adjusted my air/fuel mixture to 4 turns out and then synched my carbs. Same Symptoms.
So I don't get it. It never dies at speed and if I hold the throttle over 2000rpm when I stop, it doesn't die. If it were an electical problem I would expect it to not matter if I was stopping or going.
So I'm out of ideas and I don't want to give up and take it back to the stealership where they will not be able to reproduce the problem and just waste my time (and probably try and charge me for it too).