The idle screw is located on the bottom of the carburetor, just below the throttle slide. It is a small, brass screw with a spring around it.
High End Screw
The high end screw is located on the top of the carburetor, near the air filter. It is a larger screw than the idle screw and does not have a spring around it.
How to Adjust the Idle and High End Screws
1. Start the engine and let it warm up for a few minutes.
2. Turn the idle screw clockwise until the engine begins to race.
3. Turn the idle screw counterclockwise until the engine idles smoothly.
4. Turn the high end screw clockwise until the engine begins to bog down.
5. Turn the high end screw counterclockwise until the engine reaches its peak power.
Note: The idle and high end screws are interdependent, so you may need to adjust both screws several times to get the perfect setting.
