Ash:
I've been looking at a lot of sites telling you how to work on these 610's
and it seems fairly easy to tighten up the clutches. Take of the big nuts on
the side panel on each side and remove the cotterpins holding the clutch
shafts. Tighted the nut just a half turn on each and try it out. If this doesn't
make it turn better try another half turn. If tightening them doesn't help then
you may need to replace the clutch disk's. This is fairly easy also. just take
off the nuts, remove the chain sprocket on each shaft, replace the disk and
put it back together. I have a service manual that I got with my machine and
most of the repairs are explained and seem fairly easy. Hope I helped.