Vernier-Assist Throttle Control Assembly 
How to reassemble the roll pins in a McFarlane Vernier-Assist throttle control.

This control has all the fine adjustment benefits of an old style push-button release vernier control, with the simplicity, responsiveness, and jam-proof safety of a friction lock control.

These light weight controls use a patented drive mechanism. The new roller action vernier provides smooth, jam-proof coarse and fine adjustment without a release button. Coarse adjustments are made by pushing the knob inwards or pulling the knob outwards. Fine adjustments are made by rotating the knob clockwise or counterclockwise.

For more information, go to Vernier-Assist Controls.