How to adjust the idle screws

[Kiwi]

Ok, so my bike is idling rough and is slow to return to idle.
I've got the sync as close as i can.
I can adjust the idle screw on the front carb, but how the heck do you reach the back one?.
I see all these posts of how to adjust the screws, but not how to actually reach them.
I have an 82 with the flapper air box.
Thanks !

[Lucky]

long thin screw driver with a slight bend works for me.  doesn't fit perfect, but close enough to do the job...

[Neil]

I do it with a long thin flat blade screwdriver resting on the 14 mm bolt head that holds the cylinder head/frame bracket to the rear cylinder head. (Taking that bolt out makes it a bit easier, but not much.)The screwdriver will reach the pilot screw at an angle, but it works. I combine that with several carefully chosen curse words directed at Yamaha's engineers for making that screw so hard to reach!