If it were only that simple!
This engine is designed to idle with the throttle blades completely closed. By turning that screw you are advancing the timing and opening all three throttle blades as well. Lots of things have to be loosened, shortened or lengthened, and lined back up to do it properly. Properly is the key word.......
There is a procedure called "Sync and Link" that has to be done. You would best be served to purchase a shop manual for the engine, find the procedure and follow it.
It would take a book to write the process for you here.