What would cause ones engine revs to increase if one moves their handle bars to the left or the right?

Your throttle cable is incorrectly routed. When you turn the bars the cable is stretched and pulls the carb slides open. Re-route the cable so there is slack when the bars are turned either way.

Your throttle cable is catching/stuck on something or either stretched. I've had this happen to me, and it was because the cable was to tight whilst being held by a clip that was attached to the frame, so it couldn't move freely.

Throttle cable sticking Front tire damaged or bearings are going inner tube not seated right, Bent or loose spokes on wheel. For your safety and others have this bike checked out asap!

the cable needs adustment