If you are stuck, a way to get the butterflies sync'd is:
Engine off.
Need to have a few mm of free play at the cables when twistgrip is at rest position.
Place chin on tank with eyes to front, one ear each side.
Open throttle and close it quickly but not too quickly.
Listen for click of the butterflies hitting stops.
You adjust the cables to get them clicking simultaneously.
If one is clicking early, screw out the adjuster.
Adjusting the brass airscrews is best done with manometer or twinmax, but if not choice, then set both to 1.25 turns from seated.
Worth taking the screws out and cleaning them, the seats threads and o-rings, grease lightly, refit and seat gently. Then back out the said 1.25 turns.
