Velvet Drive trans/Cables

[roberttigar]

I recenty replaced the shift cable on a Model#71C that is bolted to a Perkins 4.108. The shift handle is a single that controls both gear and throddle. I understand the concept of getting the detwent positioned over the hole in the shift plate. I have the cables set so that even a slight movement puts the hole and the ball in alignment. As the throddle advances, the hole in the plate goes past the ball. I have been told that the hole and the detent (Ball) shoud always be aligned, that there is a stop screw to keep the shift cable from advancing when the throddle is advanced. Right or wrong? Thanks, Bob