On searching I found this on another forum,
"You should loosen it, but not right slack, and then run it in slip-mode (with light load) for 5-10 seconds (seems like a long time, but it's not), to have it seat itself, and work itself together.... You know if you accomplished it because it should get warm - to almost hot, but not burning your fingers, and definitely but don't burn the clutch up! If it doesn't heat up when you do that, tighten it up a tiny bit and re-run it... it needs to run under load, rubbing the plates together, to seat themselves properly. Once it breaks itself in, let it cool, adjust it by testing it out - if you see / hear it slip under normal load, tighten it by tightening each bolt by 1/4 turn. Run it again, and basically it should be on the border line of slipping under very heavy load (tractor engine bogs down). That way, you can till with max HP going to the ground, but as soon as the load surges above that, it will slip."
No pics to go along with the above. Does this sound like a good procedure to follow for a JD 647 tiller? Anyone got a 647 manual? Mine is on order and due to arrive next week.