There are 2 set-screws that need to be removed before adjusting the throwplate position. We use lock-tite when we put the set screws in, so the throwplate may be “stuck” on the shaft even after the screws are removed. Depending on how old the feeder is, you may have grime holding it in place as well. The way to remove/adjust the throwplate is to take a torch and carefully heat up*** the shaft/throwplate where the set screws were, and then wiggle the throwplate until the lock-tite/grime release. ***Aluminum gets VERY HOT when heated up. Be very careful and be sure to wear very thick or a couple pairs of gloves to avoid burning yourself***
We recommend adjusting it in 1/4″ increments until you get it to your liking.