I have another problem with my car

the 600 cfm (1406) edel. carb has mechanical secondaries (i think!!) and i believe they are opening too early, it seems like they open just after half throttle

up to just under half throttle i have plenty of torque, but just over it seems like it just bogs out too much and the engine loses some power


my question is:

when should the secondaries open (and how do i adjust them)?