I just solved a problem that has been plaguing me for months, and I thought I should post what I found, in case it's helpful to someone else. The problem was that my Well Tempered Classic (with the round motor) has been suddenly dropping its speed to almost nothing. Over time, I discovered that if I pulled up on the pulley, I would hear a little click and it would return to the correct speed. Then, after some time playing at the correct speed, it would again drop to almost nothing. I tried lubricating the shaft with sewing machine oil and replaced the belt, but the problem persisted. So I started looking into finding a replacement motor, but that is really challenging.
I had resisted the temptation to take the motor apart, because I feared I would kill it. But left with no other options, I did take it apart last weekend. I removed the long bolts holding the whole assemble together and pulled up the white plastic block that sits on top of the lead base. That lead base has a deep narrow hole in the bottom, and at the bottom of the hole is a white plastic hex socket. When I took the motor apart, I found that that socket is one end of an adjustment screw. The screw passes through the white plastic block and then presses on the bottom of the pulley shaft, apparently to address the very problem I was having. So I turned the screw clockwise, to raise it against the shaft, and the motor has been working perfectly for several days now. I'm not ready to declare total victory until it has run for a few weeks, but I'm really hopeful. And I hope this is helpful to someone else.
