I have a 2006 Yamaha Grizzly 80 that idles fine and clicks into gear but will not move when I pick the rear tires up and give it throttle the wheels will move slowly but if it's on the ground it doesn't have enough power to pull the bike. Any help would be greatly appreciated.

Sounds like clutch plates worn or some other problem in the clutch area.Not sure if you have a clutch tension adjuster on this model. Yamaha ATV Parts 2006 GRIZZLY 80 - YFM80GV CLUTCH Diagram Plus make sure the rear tires turn ok when in neutral and not dragging because of brake problems.