RE: evolution 46 low speed needle
I have not owned an Evolution engine but on other engines I have found 3 turns out to be a good starting point.
The engine won't run if too lean but will if it is too rich. Too rich will cause hesitation and stalling when advancing the throttle.
The pinch test works on idle setting as well as high speed (pinch the fuel line, if it revs up before dieing it is rich if it just dies it is lean)