I'm not familiar with the book you referenced, but did you open the controller and check that the full speed contacts come together when the button is depressed all the way? If they don't, you could try bending the upper contacts a little. Adjusting the lock nut and the screw is a bit of a tricky business. If the screw is too tight, the current will still flow even when the button is not pressed, and the controller gets very hot. As manicmike said it would be easiest if you could rule out the controller by testing the machine with a spare.