Yamaha Jack issue

[John Formsma]

On Wed, Mar 19, 2008 at 3:03 PM, pianolover 88 <pianolover88 at hotmail.com>
wrote:

>  Just so happens the piano in question in my case is *also* and M500.
> Well, after putting action back in and checking LM and everything else I
> could think of, the problem seemed to have "lessened" somewhat, but some
> jacks still hang up for no apparent reason. I did pretty much everything you
> did as well and now I'm thinking the only thing left is to replace ALL the
> jack springs with a more heavy duty, stronger spring to insure full return.
> I would rather do this then stretch out the existing springs. I realize that
> this will make the touch heavier to some degree, and explained this to the
> customer. Although I could find some jacks still hanging up, when she sat
> down and played she was happy with the results and , and didn't seem to
> encounter any problems...yet.
>
> Terry Peterson
>

Before you do all that, check friction like Patrick said.  If the friction
is normal ...
... make sure the jack is not being forced into the letoff rail, and held
there when in check.  At the end of the jack's arc, there should be a
minimum of 1mm clearance between the jack and the letoff rail felt.  It
might look like there is enough clearance, so examine carefully.  If there
is not enough clearance, you need to move the leftoff rail back to you
slightly (away from the strings).  If you move the letoff rail, you'll need
to reset letoff.

-- 
JF
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