KZ440 Clutch issue

I'm bringing a 1980 KZ440A1 back to life and I'm having some clutch issues. When I pull the clutch lever in, I get very little resistance and it doesn't seem to be disengaging the clutch at all. The only resistance seems to be from the clutch release spring at the end of the cable. I took the cover off the left side and cleaned, greased, and adjusted the clutch release and clutch cable to no avail. The next step after that was to take the cover off of the right side and take a look, but the nut at the end of the crankshaft that holds the ignition advance wasn't cooperating. Does it seem like I need to get into the clutch itself, or is there something I may be missing with the clutch release? If I need to take a look at the clutch, do you have any suggestions for getting the crankshaft nut off the end?

Thanks for any advice. I'm new at this and this board has been a great help already, but I'm a bit stuck for now.

i think on the later 400/440's when you adjust the clutch bottom out the handle adjustment and the cable length adjuster. then at the engine you loosen the jamb nut turn the adjusting screw in till you feel light resistance then turn it in 1/4 of a turn and tighten the jamb nut. then adjust the cable length adjuster till you have about an 1/8 inch freeplay at the handle. most bikes on the engine adjustment you back off the screw 1/4 turn but the 78' and newer you tighten 1/4 turn. still check a manual but it is a place to start before you go into the clutch.

Yep, it was an adjustment issue. Thanks for the suggestion. I went back through the service manual step by step and it's working. I don't know what I missed the first time, but this took care of it. I got to take it for its first little ride since I got it and had a big old grin on my face tearing back and forth down the alley behind the house. There's still plenty of work to do, but I know it runs and most of the major stuff is functional, so that's a great start.