I recently saw a post on this, Tried it and was amazed. Instead of looking into the carb at the needle to disapear try adjusting the cable to where the rpms increase, back off and make sure they don't increase when handlebars are turnedfully to the left or right. I found about another 1/4 inch of adjustment was still there. YE-HAH, give me some sand!

 

Yes, that will work, but I am the type that likes to know exactly what is happening, and have visual verification that the throttle is doing exactly what I want it to do, so I take the extra time...

 

you can't easily see the top of the carb without removing the airbox. I thought it was good as it could get till I tried it.