cutaway

Hey everyone, I’m running over the carbs on my 79 special. I’ve got everything up to spec, but I am interested in how to determine my throttle cutaway. I know what cutaway is but in my manual, the spec for my cutaway is listed as #120. Can anyone tell me what this means?? cheers!

Would anyone have any tips on grinding/filing a carb slide cutaway? I had a 2.0 slide installed on my VM34’s but I was getting the black plugs after 50 mile problem. Throttle response was great though. I moved to a 2.5 slide to cure that problem but now my initial throttle response is poor due...