You might consider this item: Randakk’s GL1000 Carb Rebuild Video
Recently, a GL1000 owner was in my shop with an odd complaint. He reported that very heavy pressure was required at the throttle twistgrip to increase or maintain engine speed. Suspecting that the throttle cables were worn or damaged, the owner had just replaced both throttle cables, but this offered no improvement.
My test ride verified that indeed there was something amiss. This bike ran great, but after just a few miles the effort required at the throttle made my right forearm ache!