Check the condition of the knuckles, check the position of the jack and
check that the backchecks don't interfere with the hammer heel on the
way up by placing your finger on the hammer head and push the key down.
Check the action centers for stiffness, check the bushings for friction.
Check the drop relative to the letoff.
If none of this works check how many key leads are in the keys, check
the spread action measurement and consider using wippen helper springs.
This action will regulate just like any other action.
Newton
nhunt@jagat.com
This PTG archive page provided courtesy of Moy Piano Service, LLC