Hot rear PTO clutch on 620

[dallenx 0]

After getting the poor neglected tiller working and re-installing the rear PTO shaft that the previous owner took out, the rear clutch is giving me problems. At first, if I used it for a while and shut it off to turn a corner, it did not want to re-engage. I had to let it cool off. So now I leave it on while I'm tilling and just pick up (not to high) the unit to make my turns. Yesterday, the clutch shut off while tilling and I found that the tractor body plate over the 'hump' in front of the seat was to hot to touch so I had to wait to see what was wrong with the clutch. It turns out that the bicycle chain link came un-done and let the clutch spin and pull out the electrical plug. WHY is the clutch running so HOT?????