Gordon, Did you check for lost motion first? I'd guess that regulation will correct everything unless there is actual damage to the butt leather. If some hammers are bobbling, that's generally an indication of the blow distance being too great. Or the capstans are not high enough (too much lost motion). Also, checking should be closer than 1 inch, which will also help correct the bobbling. Check the capstan height (aka lost motion) first, though, as this will have an effect of checking distance. I sure would look at everything else before filing the jack top. That would be the least likely on my list. Not saying it ain't so, but Yamaha has made millions of those things and it would seem we'd have heard about from them if there were a problem. John Formsma > My first efforts, however ( after regulating the > action ) will be to reduce the hammerstroke, and > perhaps increase the keydip by 1 mm.
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