Allan, I'm not finding the diagram easy to follow, mainly because I don't have the machine itself here. The owner's manual says that the wheel-drive clutch operates by tensioning or releasing the drive belt: you push the pedal to declutch, then pushing it further applies the disk brake. From the parts diagram, this seems to be done by a push-rod that attaches to the pivoted link on which the jockey pulley is mounted. It sounds as if you may need to adjust the length of that push rod, so that the pulley slackens the belt when you push the clutch down, before the brake is applied. The owner manual tells you how to make the adjustment. Unfortunately the photocopy in the manuals section was made in black-white, not grey-scale, so the pictures are useless. However the words make the process fairly clear. My current interpretation is that there should be a clearance of 3 mm between nut 67 and block 78 when the clutch pedal is not being depressed.
Please post some pictures - it will help us all to understand the system, and will improve our archives after your problems are solved.
