Poulan 2055 Carburetor Adjustment . Set the highest rotation speed on the tachometer with. Prove the efficiency of air filter use. Carburetor Carb Intake Manifold Gasket Set For Poulan 1950 2050 2150 from www.aliexpress.com Clean the air fiiter using hot soapy water. Adjust idle speed with screw “t”, turning counterclockwise until stable operation of the motor at idle speed; If the engine runs rough, then the carburetor may need to.