It"s not the greatest design, but it does work well if the entire throttle assembly is maintained properly.
I"ve found that disassembling the linkage under the 430s battery box, making sure all parts moving freely, and ensure the springs are all in place is a good start. Then make sure the ball joints that attach to the governor "T" up front are free. Finally, inspect and replace (if necessary) the bushing where the vertical rod connects to the foot throttle. - Joe