At first it was hard to get into neutral. Then about 3oo miles ago it started not to down shift. It felt like something was locked in place. If I double clutched it then it would down shift. I asked my mechanic what he thought it was he said maybe clutch needed adjusting. I did this and adjusted the cable. Didn't help. Still wouldn't down shift. Will only go into neutral when motor is off. Now while moving it sometimes won't shift into higher gear. What might could be the cause of all these problems? The bike has 70,000 miles on it does the clutch pack need to be changed?