Motorcycle Repair: 86 YAMAHA CLUTCH, clutch lever, thrust plate

Question
Hi,
I have a 86 Yamaha Radian 600 that I just rebuilt the engine on.  And I am having a problem with getting the clutch to disengage,(when its in gear and you pull in the clutch lever it's still in gear). I put it back together just like the manual explained, lining all the tabs on the metal plates with the marks on the cluth boss, and the dot on the cluth boss with the dot on the pressure plate, and torqued to all specifications, adjusted the clutch cable so there was no play, and nothing the clutch will not disengage.  I did drive the bike with out using the clutch shifting through all the gears with out the clutch.  I don't know if you should be able to do this. I did see a part in the manual that I did not have, it is the thrust plate.  It goes between the clutch housing and the clutch boss " like a big washer", is this the problem?  I do not think that it was in the clutch before I took it apart, but it is possable that I lost it. I used SAE 20W 50 motor oil.  I have worked on many cars but this is my first bike and I am at a loss.  Any help you can give me whould be greatly appreciated.
Thank You,
Mike

Answer
Hi Mike.
 That missing part is the key.  I am certain that it got lost while you were working on the tranny.

 Since it is a small part and critical, you must take great care to not lose it.  Go order a replacement and install it.  Your problem should go away then.

Good luck.
FALCON