ORIGINAL: Artisan
Opjose, please understand this and get it through your noggin' - THERE ARE NO FACTORY SETTINGS.
If the engine is runnable out of the box with the stock needle settings, it is a complete accident. A serendipitous occasion, for sure.
Eh, Not true.
The Evolution engines have limiters on them that prohibit moving the needles outside a specific range.
The documentation tells you that you are NOT to move or attempt to move the needles outside the limiter range.
The engine is "preset" so that you can only perform minor adjustments as it comes out of the box. Check the advertising blubs as well, that also re-inforce this.
The problem (at least for me) was that the low speed limiter coller did not permit the idle speed needle to travel inward beyond this preset range, even when I loosened the grub screw on the collar.
The limiter collar would stop the low speed needle, even when I attempted to screw it in, with the grub screw fully loosened.
The collar would make it seem as if the needle had bottom out, even when it still had a good travel range.
Removing the collar altogether solved this.