Need urgent help with my clutch problem; GS450

Hallöle, have a big problem with my mopped, and I just can’t find the mistake. I’m actually a good screwdriver and have solved all the problems until now. However, I now have a clutch problem and don’t know what to do. Now to the problem: I have a Suzuki Gs450 Bj. 89 My clutch train became more and more difficult to pull over time. This then went so far that one had to pull with such a force that I got a tendon sheath inflammation and finally closed the train n is. So: I bought a new train, everything was nicely oiled. The screw on the clutch cover sparks perfectly. The train is also very smooth in the detachable condition. However, when I screw on the clutch side again the train is extremely heavy again. Clutch spring and oil I changed in retrospect, no improvement. Thus I can not get normal force to pull the train and separate the discs. Someone can help me. Have tried everything already. Thanks cucu kok