I noticed that when I shift out of neutral into first, i get a little bump forward, but then it's fine. I had my bike jacked up today and then when I put it into first, even with the clutch lever in, the back wheel starts to rotate. not slowly, but not fast either. also, if the bike is off and is gear, i can't move it even with the clutch lever fully in. when I'm sitting on the bike ant have it in first with the clutch fully in, it doesn't move. what's going on?