Flying Horse 2-Stroke Motorized Bicycle NT and Speed Carburetor Idle Adjustment Screw With Spring &ndash; Gas Bike Idle Screw Replacement The Carburetor Idle Adjustment w/ Spring is the replacement for the idler screw on the standard NT carburetor Installation is simple: just remove the existing spring and idler screw, align the replacement parts, torque in to the carburetor, and you're ready to ride Note: This screw will only work within the standard NT carburetor. After removal/installation of the screw you may need to retune the carburetor for peak performance