Mostly trial and error to get the linkage just right. The best advice I can give is try turning the carb slightly. And then readjust throttle arm so it gets most movement without binding.
This might help:
Doesn't that affect your brakes having a tight spring like that? In other words having a spring there would make your brakes weaker.
BTW: In another post you mentioned getting an OS11K carb. Which one did you get? There are two different ones. One of them is made specifically for the Revo. The...