OK,

The screw on the side is the low speed mixture screw

Before turning that one, lets get the high speed set first which it is down inside that tube.

If however the low speed mixture is too rich (and that is typical of factory settings with these type engines ) it can cause flooding or partial flooding which can make the engine very difficult to turn over. (and it's very hard on the pull start mechanism )

The spitting and sputtering from idle through transition to higher r.p.m. means it's loading up...and the low spd. mix needs leaning out a bit. Turn the low spd. adj. in CW 1/8 turn at a time to sneak-up on it.