I agree on trying to bleed the clutch. If you still have the problem after trying to bleed it I have heard you can get something to tie the clutch handle to the handle bar and leave it that way over night. It will let any trapped air in the system to go into the master cylinder. I have not done this so I do not know if it works.
dot4 brake fluid was $ 5.18 with tax at autozone. i refilled the reservuar then took some twine and tied the clutch lever back to the grip. i'm going to leave it like that untill tomorrow and see what happens
Just did mine on my 84 aspy I used a mighty vac. loosened the bleeder at clutch and slipped the tube from vac over it. Pump it down and open the bleeder valve,just make sure to keep the res full. Pulled the old dot4 out quick and the new in and no air or bubbles. Good luck Hal