Small Engines (Lawn Mowers, etc.): carb problems, snow blower, neutral position

Question
hi ben..merry christmas to you and your family,
recently i clean my carb it was a mess.i have three settings on it.one is idle  and other is the main one and a idle speed screw.if you were to set up the carburetor,which one will you start with?what is the idle speed screw for?when i start it ,it runs rough and when i take off the choke it stalls?toro snow blower model 31625 502081.
merry christmas and have a safe holiday.
    greg

Answer
Greg
Merry Christmas to you and yours..........
First you need to set the screws at a neutral position. Start with closed and turn 3 half turns. Then start the engine let it idle and then set the idle first  once the idle is set. You can then speed the engine up and adjust the high speed you will see the engine try to stall and then rev up get it at a clean high speed.