Transition slot position can vary from carb to carb , some will set the throttle blades to just uncover the trans slot , this causes issues if that particular carb has the trans slot set higher up the throttle bores , all this does is pull fuel through the intermediate tube @ idle due to the throttle blade angle , some guys will set the idle speed & if it does'nt pull main metering they assume there good to go , forgeting it's dumping fuel through the intermediate tube.