Carb. adjustment '99 Merc. 50hp 2 stroke

[oceanbound]

I just purchased and received a new carburetor from boats.net, great. Is the screw on top of the carb. pre set? or need to be set? and also, how/what should the other 2 carbs be adjusted? with the screw all the way in, how many turns out? (yes the other 2 got messed with). Almost ready to go!
Thanks,
R.James in Pompano

[boats.net]

It would need to be adjusted with motor running in water at idle.