Sorry- should what help with throttle response?
This could get confusing.
Let's start over.
Let us know:
Stock filter? Stock muffler?
How much of the white spacer did you remove?
What jets do you have? Are they Mikuni jets?
To the nearest 1/4 turn, how many turns is the idle mixture screw turned out?
What does the spark plug look like after at least 1/2 hr run?
What specific performance issues are you having? (start with that.)