Slow Console Action

[Farrell]

Not really slow, but rather when you lift your finger up off a key slowly, the jack will not slide under the hammer butt. I believe this to be a somewhat common problem on these little pianos. This one is a 1960ish Kohler & Campbell console. Clearly, the key is front weighted enough that the wippen is not able to return the key to resting position fully and thus let the jack slip under the butt. I lubed the action liberally with Protek and eased all the keys - got everything as loose as I reasonably could - the jacks still get stuck when lifting off the note slowly.

I suppose the jack springs could be a bit on the weak side. On a well designed and manufactured vertical piano in good condition, should the weight of the wippen be sufficient to push the rear of the key down to rest on the backrail felt? I should think so.

Have I missed anything? Any recommendations?
  
Terry Farrell