No, you do not need two cables. The hand controls for your year only have one cable. The reason for two cables is that one is a back up to shut the carb incase the throttle return spring breaks.
I believe the two cable thing came about because of federal regulation. Like the one that states, 'after a certain date, all murdersickles must have the shift on the left side.'
The Feds did not want our throttles to hang up in the open position, so they made it mandatory that a cable be used to open, and another cable be used to close the throttle. Like that big honkin' spring inside a barrel carb was not going to do it.
If I am wrong about this, someone please correct me.........pg
If you ride in the woods much like I used to, you will learn to appreciate the dual cable setup. I snagged the throttle cable on a limb one time and the throttle stuck wide open. Not Fun.