1. Fuel Petcock Types: There are manual and vacuum petcocks. Most GSX 750 Katana models between 1995-1997 equipped with mechanical petcocks.
2. Fuel Selection (ON, RESERVE, OFF):
- ON: Allows fuel to flow freely from the tank into the carburetor floats in the "bowl." When the floats reach a specific level (determined by the height of the float needle valve), they close, stopping the fuel flow.
- RESERVE: When the fuel level in the tank is low and the fuel petcock is switched to the "RESERVE" position, fuel from the reserve section is drawn through a separate outlet on the fuel petcock, allowing the rider to continue riding for a limited distance.
- OFF: Completely cuts off fuel flow from the tank to the carburetor. This position is used when servicing the fuel system or storing the motorcycle.
3. Vacuum Operated Mechanism: On vacuum models, a small fuel line connects the vacuum petcock to the intake manifold. When the engine is running and creating a vacuum, this vacuum signal acts on the diaphragm in the petcock. The movement of the diaphragm controls the fuel flow - as the vacuum increases/decreases, it ensures an appropriate fuel supply.
4. Fuel Strainer: The bottom of the fuel petcock assembly contains a fuel strainer. This strainer helps prevent contaminants in the fuel from entering the carburetor. It is important to periodically inspect and replace the strainer as needed to ensure proper fuel flow.
Remember, refer to your specific motorcycle's service manual for detailed information and step-by-step instructions on fuel petcock operation and servicing.
