Viton Inlet Needle & Seat

The Viton Inlet Needle & Seat (HLY6-518-2) is a precision fuel metering component engineered for Holley carburetors, delivering reliable fuel regulation in both street and performance applications. This adjustable needle and seat assembly is essential for anyone rebuilding or restoring a carburetor, whether you're returning a classic muscle car to original condition or fine-tuning a high-output engine. The Viton construction ensures durability and chemical resistance, making it the preferred choice for fuel systems exposed to ethanol blends and aggressive driving conditions.

The 0.120-inch orifice design controls fuel flow into the carburetor bowl with precision, maintaining consistent fuel pressure and preventing both flooding and lean-out conditions during acceleration and idle. Viton sealing material resists swelling and degradation from modern fuel formulations, significantly extending component life compared to natural rubber alternatives. The adjustable design allows mechanics to fine-tune fuel delivery characteristics to match specific engine requirements, carburetor calibration, and driving conditions—a critical factor when diagnosing or correcting fuel mixture issues on performance builds.

This replacement assembly is ideal for carburetor rebuilds, engine swaps, and fuel system upgrades on vehicles running Holley carburetors across multiple platforms. Installation requires basic carburetor knowledge and proper seating to avoid fuel leaks; most experienced mechanics can complete the swap during a standard carburetor service. The pair configuration ensures you have both inlet needle and seat components needed for a complete, leak-free fuel metering system, reducing downtime and supporting reliable engine operation on the street or strip.