Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Should my lower action be uneven like this? Kawai No. 600

Hi, recently inherited this 1969 Kawai Model No. 600.
I removed the action for deep dust/crud removal.
I also removed the upper part of the action to blow out dust from inside
the action. The lower action is very uneven looking.
I don't know a whole lot about these actions which is why this is being posted.
The hammer butt ropes are all intact as are the metal springs/hooks.
Is this ok or does this mean the action is pretty much worn out and needs rebuilding? Seems to play ok but more force does seem needed to press the keys while playing, the keys don't seem to be as bouncy/responsive as they could be.
Seems like people say this model is past its expectancy but it still plays and it was free, a family hand me down. Thoughts on this lower action? The only other thing with the piano is one single broken sostenuto tab spring broke. Tried to fashion a small paper clip but was too thick. Not sure where to get one of these tiny springs.


[img]https://drive.google.com/file/d/1CtpF4KqorxAaL9j5k1z0SaU60TbebjOY/view?usp=drivesdk[/img]

[img]https://drive.google.com/file/d/1CzIHZRz__I6Ho4dkhefPgQh_HAPy1J1h/view?usp=drivesdk[/img]

Your action looks like it needs some regulation, but the parts look ok from what I see. Just put it back together and be carful not to break anything.

Also, I don't recommend taking an action apart like this.

Varying tension on the auxilliary wippen springs will cause this. It is normal.

You are probably going to have to fiddle with the action spread to put the piano back together properly.

I have never seen anyone offering sostenuto tab springs separately. If you cannot fashion a spring yourself using proper wire for it, you might need to get a new underlever.

I second what Bill said about taking an action apart like this, if you do not know what you are getting into.

you shouldn't take whole hammer rail off, now you will have a problem because if you don't reinstall it where it was with precision of at least +-0.1mm, whole regulation will be off and treble hammers strike point will be off

thank you for the input. I blew out a lot of dust and put it back together.
There is no adjustment for the part I removed. The round holes are not slotted so I simply
put the upper back on carefully and tightened the non-adjustable screws.
It seems to play a little better after blowing the dust off and knocking rust off the strings with scotch brite pads. I will need to tune it again.

Kawai Acoustic Pianos Parts list
Look at Damper Assembly for the underlever.
...not sure how/where to order, but maybe through a Kawai dealer?