<html> Todd, This point especially points to something other than the pinblock fit as causing this pianos' instability. Having difficulty tuning a unison and keeping it there is usually a string rendering difficulty, together with possibly poor voicing.  Stiff wire combined with flattened hammers, in a piano where things are getting sticky (bridge and capo) from age, combine together for difficult tuning. Here's a little guideline to follow regarding tuning instability: - If you tune a note and it drifts under a hard blow, then changing tuning technique will usually get you over the problem.  This is a very common type of tuning instability complaint, and changing the way the string and tuning pin are settled into tune will solve it. - If the strings stay under hard test blows, but the section drifts as you tune up or down the scale, then you are likely fighting temperature swings while tuning, together with the usual affects of a pitch change.  This might also be caused by loose plate screws (including in the pinblock and the rim) or possibly a rocking pinblock (meaning the lack of fit could be contributing).  Honestly, the lack of fit on a Yamaha doesn't usually cause a problem in this way unless something else is also wrong. - If the piano stays in tune on the short term (like through a hard concert), but drifts out after a week or so, the problem is a combination of heavy use and / or climate control. As my mentor used to say to me when I was complaining about something: "Let it be a challenge to you."  Or at least to your friend. Don Mannino RPT At 06:07 AM 1/12/01 -0600, you wrote: <blockquote type=cite class=cite cite>Jim, Make a suggestion as to what other cause there might be.  My friend is a competent RPT and I don't doubt his evaluation.  Perhaps, though, you could shed some light on the matter, since you seem to be so knowledgeable about Yamaha construction techniques?  What other problems have you run into that caused tuning instability.  My friend said it took him 20 minutes to set one unison.  How's that for instability? Todd On Thu, 11 Jan 2001 17:42:53 EST JIMRPT@aol.com writes: > Whoa Todd! > >  Are you or your friend sure this is the cause of any tuning > instability? > My view. > Jim Bryant (FL) > ________________________________________________________________ GET INTERNET ACCESS FROM JUNO! Juno offers FREE or PREMIUM Internet access for less! Join Juno today!  For your FREE software, visit: <a href="http://dl.www.juno.com/get/tagj" eudora="autourl">http://dl.www.juno.com/get/tagj</a>. </blockquote></html>