My Tao Tao 250cc won't move
 

So my atv starts and runs and goes in gear but won't move. When I jack the back of the atv and start it and put it in gear the wheels move and it shifts. When you put it on the ground and no one is on the atv and you put in gear it doesn't move even when you give it throttle. This is a Tao Tao 250cc engine.