If I knew the make and model of carburetor I might be able to help. For what it is worth, most of those chainsaw-type carburetors use a starting-point for tuning of around 1.5 turns from shut off (all the way in) on both mixture screws, but it varies by about a quarter of a turn, and that amount of error is a lot with those carburetors. You might try 1.25 to 1.5 turns - once you get it running, adjustment is a simple process.
