I don't know...most engines comes out of the box at a rich setting ready to be break in.
99.9999999% they fire up on the first try if I use an electric starter.
Depending where you live, outside temp...etc. You might need to trun it 1/4 trun eiter way.
I've yet had to un screw 4 complete turns on any HSN in all my years of R/C or anything else.
And I've yet to turn any settings more than 1/4- 1/2 at a time, especailly during a break in.

Generally 2 1/2 turns out is a rule of thumb for a starting piont for any kind of needle setting.

I worked at a power plant for years and came acrossed all kinds of comtraptions.
I have all kinds of certificates from catiplliar.
I even took a college course on small engines....so what