May 28, 2011 12:25 PM PDT
Idle is actrually set electronically with a device called a Scanalyizer, and you probably don't have one.
Two very common causes for a high idle if nothing on the bike has been changed since it was running ok...
First check to see if when the throttle is released that it is going all the way back to the stop screw (see picture below). If it is not then either your throttle cable is binding or needs to be adjusted to allow some play. The throttle cable should be adjusted so that there is a tiny bit of slack. When you turn the throttle a hiar the should be free play.
Second check and see if the butterfly stop screw has backed out (see picture below).