hmmm, I see what you mean to adjust the "throw" of that plate but it looks like the plate itself can’t be moved. somethings way out on the linkage and im thinking its the gear mesh on the throttle handle?
cam right off the roller , full throttle,
throttle full off "start position, no where near the hash marks,
throttle full on
throttle full off, start position, all they way to the end of the gear mesh
somethings not right,,,,
Cliff