Which component blocks the main jet during cranking, creating rapid fuel pressure in the system?

• A. Metering Valve
• B. Fuel Filter
• C. Main Bypass
• D. Shut-off Valve

Answer: (C)

When starting, the fuel system uses a starting or priming path to get more fuel into the engine quickly. The component in question creates that quick surge by diverting fuel away from the normal main-jet path. It temporarily blocks or bypasses the main jet and sends fuel through a separate bypass channel. That diversion increases pressure in the supply line and delivers extra fuel for cranking, helping the engine catch and start. Once the engine fires and speed rises, the bypass closes and fuel flow returns to the normal main-jet route.

The other parts aren’t designed to produce that immediate starting surge: the metering valve mainly controls fuel during normal operation, the fuel filter only cleans fuel, and the shut-off valve stops fuel flow when the engine is off.