screw in throttle screw until fast idle...
normally to richen the mixture screw out.
screw in to weaken the mix.
screw in mixture screw slowly until feeling resistance DO NOT OVER TIGHTEN.
screw out, 1 turn
alter until you get a good balance between high and low revs. only very small amount at a time.
In your case you probably need to richen it.
cc
February 2016