Answer:
Go to your local autoparts store and by the rebuild kit according to your carburetor. Inside the box will be an exploded diagram of the carb which will make it relativly simple to rebuild
First of all what kind of engine do you have. Briggs and Stratton or Tecumseh. If you have a Briggs & Stratton engine the factory setting on the little black screw is 1 turn out, Tecumseh engines 'usually' do not have adjustments. hope this helps