If the clutch arm (the part on the left side of the motor right in front of the sprocket) is hard to move, you'll need to remove the pushrod, the ball, and the clutch arm. Something is wrong. Without the pressure plate tensioned, the clutch arm should move freely. The pushrod and ball should slide out of the shaft with little effort.
If this is not the case, you need to find the source of the problem and repair it or your clutch will never work right.