Young Chang action noise -Reply

[Steve Pearson]

Is there any possibility that the tail of the hammers are tweeking th
whippen flanges?  You might also look to the knuckles themselves.  I
have had experience with such knuckles in the past being so hard and
tight that they actually sounded like a wee tiny tap dancer.  Inserting
something like a knitting needle or other dull instrument thru the knuckle
between the skin and the felt.  Be careful not to overdo it.  You don't
want loose knuckles!  A few swipes of a suede brush on the leather (or
what passes for leather) completed the job.  This solution followed two
other "fixes" by different techs, both of whom denied the possibility that
this could be the problem.  I was able to prove the theory before
plunging in feet first by simply holding the key down and dropping the
hammer.  The thwack was unmistakable.  And several years later, it is
still quiet, aided only by the occasional "brush up" from the suede brush.
 BTW, this was before I joined Yamaha tech support, and reflects my
personal opinion.  But it works!
Steve