The belt chirping most likely is caused by the belt being too loose,
or whining it is to tight, or may not be tracking in the center of the pulley or as close to center as possible.

The Road Star belt has a strong tendency to run to the inside of the pulley which is ok.  Some owners have reported that they think the coating on the teeth portion of the belt wears off and causes some noise, I haven't experienced it but anything is possible.

With the bike on the kickstand, push up on the bottom of the belt. Measuring in the middle of the belt, see if you have 1/2" up & down movement.  If so, the belt should be ok. 
                                                          
If the belt is to tight it puts a lot of strain on the pulley bearings.
(Not a good thing)

If you need to adjust the tension do it with the bike on the ground, reason being is you need some weight on the tire so you get a better belt tension as you ride.  The belt is looser with weight on the bike, so I have my wife set on it when I adjust it.

Here's how I do it, bear in mind you can get a 100 opinions as to the best way to do this, but this works for me.  Loosen the rear brake caliper bracket.  Loosen the axle nut (crescent wrench will do) its on the right side, the left side is the axle bolt.

Loosen the rear axle adjuster nuts & when you either tighten or loosen the belt make sure to turn the adjuster bolts the exact same amount. 

If you need to center the wheel you need to jack the rear wheel off the ground.  I always keep the front tire touching the ground for stability.

The adjustment hash marks on the frame have been known to be off, so to center the wheel measure from the center of the swing arm bolt to the center of the axle when that's the same on both sides its centered.

Once centered you can adjust the tension but turning the adjust bolts a 1/4 turn at a time the same on each side.     Be sure to tighten the locking nuts on the adjusters after you have made all your adjustments.

Then tighten the axle nut to 65lbs (the book is wrong), crescent wrench works good.     You can lay down behind the bike and turn the wheel with  your hand and see how the belt tracks hopefully in the center.  If not, repeat the adjustments again only in smaller increments.

The last thing is to retighten the brake caliper bracket.
I have forgotten this before. (not a good thing)

Bear in mind this is how I do it and I'm not advocating you do it my way that is your decision.    Anybody can make suggestions about this if it makes it simpler or safer.
(Paul- TenFeathers)