I've been noticing recently that after riding my '84 R65 for 10-15 minutes that it begins to be more of an effort to shift, particularly going from 1st into 2nd, and 3nd into 3rd gear. When I pull in the clutch and pull up on the shift lever with my toe, it sometimes feels as if the lever won't budge at all, but if I relax my toe and then pull back up again, it will go into 2nd with a noticable "clunk". Same for 3rd gear. However, if I shift sooner than at about 3k (like around 2k), it will often go into gear without much effort. But then the engine lugs.
In addition, I have also noticed that at times when I downshift from 5th into 4th, or 4th into 3rd that at times as soon as I push the lever downward with my foot and it "clunks" into gear, the engine revs go up, as if I have already let out the clutch, even though I hadn't yet. I thought perhaps the adjustment screw at the clutch lever had gotten out of adjustment, but tightening it up didn't seem to have much effect on the upshifting and downshifting. The bike currently has a little over 118k miles and runs OK other than the shifting. Any ideas and recommendations to get things back to normal? I should add that I am not mechanically inclined to be able to go inside and begin tinkering around, and would rather have someone more qualified than me to make any needed adjustments. Any thoughts or suggestions would be appreciated. Thanks! John