That kind of behaviour sounds like an electrical fault to me.
When did you last check that the power valves rotated freely, and weren't sticking through carbon build up?
Check the throttle position sensor is firmly screwed to the right side of the carbs, and get a multimeter on it to check the resistance changes smoothly as you slowly rotate the throttle.
Check the plugs to the PGM (in the seat hump) are firmly attached.
Could also be an earth fault, so check the battery cables, and earthing lead to the frame are making good contact.
_________________
MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball
