The last few days' discussions of Ampico pump problems have been
interesting, but I have another pump problem:  The piano shakes!
Other than that, the pump is quiet and provides sufficient vacuum to
play the piano. The motor pulley appears to be the original diameter.
It's in a 1919 Chickering (Stoddard Ampico).  Where do I look?

Glen Jedlicka

 [ Look at the legs.  Maybe the glued joints should be repaired.
 [ You could try bolting a counterweight on the big pulley, in
 [ order to counter-act the force generated by the unbalanced
 [ crankshaft assembly.   -- Robbie