In a letter to Wayne Stanke, Bob Taylor mentioned that the Ampico B
regulator spring has undoubtedly weakened over the years, and is
designing a roll to test this feature. For those interested, Player
Piano Co is now selling my Ampico B spring replacement. But I might
also add that after having done a number of model Bs over the years, I
have noticed a large difference between these springs, and attribute it
to a factory adjustment, seeing as how some of them had never been
broken into before (The old tubing was so brittle the pump could not
have been moved, and no evidence of tampering  in any other way).  The
number of coils of that spring vary widely, and I didn't care for their
method of giving a piano a little more top end. They just cut out some
of the coils --seemingly in the larger pianos-- and made the spring
stiffer. I have also measured differences in spring wire gauge, varying
usually between about
.038 and .040.

   There is absolutely no way that an old spring can have the correct
tension after having been overstretched repeatedly for 60 years. Get a
new one!

Craig B.