A carburetor (carb) is an essential component of vehicle and motor bike engines. Its main use lies within its ability to mix fuel and oxygen together to aid in the combustion process. The S&S carburetors have versatility because they can be tuned and adjusted to perform well. An S&S carburetor can be adjusted in two ways by either adjusting the air and fuel mixture to help keep the mileage under check, or by adjusting the idle to check the speed of the running engine.
Locate the S&S carburetor on your bike. Identify the idle mixture screw, idle speed screw and the accelerator adjustment screw located at the front face of the carburetor.
Make sure the S&S carburetor is set to the original or stock settings. That is, the idle mixture screw should be 1-1/4-turns from lightly seated, the idle speed screw should be a 1/2-turn clockwise from the engagement point and the accelerator adjustment screw should be two turns counterclockwise from seated.
Start your bike to bring the engine to an optimal operating temperature.
Adjust the idle speed screw clockwise to increase rpm or counterclockwise to decrease the rpm of the engine. The idle range for the S&S carb should be between 950 and 1050 rpm.
Set the idle mixture by turning the idle mixture screw slowly in a clockwise motion until you hear the engine run poorly. Then, slowly turn the screw counterclockwise until it runs smoothly without any stumble.
Turn the accelerator adjustment screw clockwise until it lightly seats while the engine is idling. Turn the screw counterclockwise 1/4- or 1/2-turn at a time until the engine responds to the throttle twist in a smooth and quick manner.
Ride the motor bike in various rpm ranges and try to maintain a consistent 40 to 50 mph. Make sure you are satisfied with the adjustments you have made on the S&S carburetor.
