To be honest with you...it is easier to do than for me to type these words on it.

There is ONE adjuster on the throttle cable, where the two cables come out of the switch housing on the right handlebar. If you twist the throttle on and off, you will see that there are two black cables protruding from the switch housing. Technically...one cable is going INTO the housing, and the other cable is coming OUT of the housing. They both go down to the throttle spool on the throttle bodies, buried deep in the bike. Do not worry about that.

Back up at the handlebar...where you can see the two cables that are entering/exiting the switch housing, only one of those cables has an adjustment on it.

I believe it takes a 10mm wrench, and possibly an 8mm wrench. I am not standing next to my bike right now, but you can look and determine what it needs. Simply loosen the set NUT that holds the adjuster in place...back that set NUT off a few turns...and then spin the adjuster on the cable housing, to either tighten the cable slack, or loosen the cable slack. In most cases, the cable will have too much slack, and most people will want to tighten the cable slack...or...remove some of the excess slack in the cable. Be sure to not...NOT...remove so much slack that you have now raised the idle rpm's. It is best to do this with the engine warmed up and at idle...preferably on the centerstand, but THAT part is not a big deal. It it were a carb'd bike, it would make a difference. Since this is a fuel injected bike...not as important to be on the centerstand.

So, the bike is warmed up...possibly on the centerstand...at idle...and you are adjusting the cable adjuster. Make an adjustment so that it is far enough...removing slack...that you DO actually raise the idle rpm's. Then...back off the adjuster until the idle rpm's go back down to where they were, where it should be, about 700 to 800 rpm's. It is really a matter of feel. I personally do not like any slack in my throttle cables. Some people don't mind the factory setting. I found that this bike had much more cable slack than any of my 3 previous GL-1800 Wings. So I noticed this, and decided I needed to adjust it.

Once you have the cable slack adjusted to where you are happy...and it is perferctly fine to twist the throttle a few times...crank it up, and then let it idle...just to play with it, and let it settle back down to an idle...once you are done adjusting this...THEN move the set NUT back into place, hold the adjuster with one wrench, and tighten the set NUT with the other wrench. It does NOT take a lot of tightening to secure this nut, so do not over tighten it.

For me, my cables are adjusted tight enough that if I even look at them cross-eyed, they get scared enough that they raise the engine rpm's.