In response to Bernt Damm in Cape Town [000623 MMD]:  Since you have
regulated everything you can find and still have lost motion, let me
suggest you go looking for everything along the sustaining pedal system.

Rebush everything in sight.  You may even have to go into the piano
action and rebush the damper rail pivots.  These are the little metal
or wood things with felt in them under the damper levers.  You may
have to take off a couple of dampers to get to these.

Look at the bushing of the damper rods going to the lift rail.
Often the loss of bushing in that hole allows the pedal rod with the
pin in the end of the dowel to slop side-to-side, and make noise as
well.  If that hole is large that slop will be lost motion.

Any connections to the damper pneumatic or pedal should be bushed.
Once this is all done, see if you still have problems.  By the way,
when it's at rest the metal damper lift rail should just be not
touching the damper lever felt.

D. L. Bullock    Piano World   St. Louis