Sticky clutch (motorcycle)

Ok it's not a mopar, but it saves me money, so I can put more in the tank of my duster :D

1978 Yamaha DT175E 2-Stroke (DT125 with an MX175 top end).

It sat for a long time, when I stopped riding it. Prior to that, it had little use (only driven in 1978, by the original owner, about 200 miles on the bike as of now)

I cleaned it up last year, put new brakes on it, new seals, repainted the body & frame, tuned it up (new wire, points, plug, etc). All to prepare it to ride on the street. Fired it up and the clutch doesn't disengage (worked when it had been parked several years before)

So I Cleaned & Flushed the Crankcase & Transmission out, filled it with fresh oil and tried to ride it again. Clutch still doesn't disengage and that's when I gave the bike the middle finger and walked away (several months ago)

Any ideas? I didn't find any water or anything in the crankcase, the clutch worked when the bike was parked the first time. Any of you older guys have some suggestions?