I've never seen this problem in a Yamaha that's being played like a piano, but I suppose it's possible. Typically, this has always been a problem with these actions with beginners, kids, and folks with a very tentative touch. To me, it looks like a design thing. The ratio of jack length to toe (tender) length is high, so any drag of the jack at the butt translates to increased resistance at the toe, which is more readily felt at the key. As the key is depressed, the pianist picks up resistance from the damper spring first. This isn't far into the stroke, isn't out of the ordinary, and is ignored. Near the bottom of the stroke, added resistance is encountered at letoff, when the jack toe hits the letoff button, and they quit pushing. When they don't push through the letoff resistance and finish the stroke, it makes the hammer bobble because the jack is still under the butt. Assuming the action is in reasonable, though not critically PERFECT regulation, the bottom line is that the person playing the piano needs to learn how to work it and the "problem" goes away. Since that isn't likely to happen immediately, I find the quickest and most easily reversible cheap trick is to bend the letoff rail brackets down a tad to make that letoff about 1/4" - maybe more. That gets the letoff resistance farther up in the stroke where they tend to push through it instead of stopping. There will be a point where even the most relentless and determined soft paw won't be able to make the hammers bobble. That's where to leave it. Feels funny? No power, no control? No sweat. If they were capable of power and control, the problem wouldn't have come up in the first place, or at least it wouldn't have been a problem unless they are just looking for trouble. Next year, when they've learned to work the piano and complain about the lack of power and control (or not), these same brackets can be bent back up to get the letoff close enough to even it out quickly without having had to crank all the buttons down, then up again. Sure, I hate to compromise a functional action to accommodate someone's inability to work it, but they aren't going to change until (and if) they change, so all that's left is minimizing the damage until, and if, they do. These actions work fine, in my opinion, but just aren't the sloppy and infinitely forgiving worn out old spinet or upright action they typically replace, and demand some portion of the player's attention to adapt to. For what it's worth, that's my take. Ron N
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