.150in Needle & Seat Assembly

The .150in Needle & Seat Assembly is a precision fuel delivery component engineered for Holley carburetors, serving as the critical control point in your fuel system. This assembly regulates the volume of fuel entering the carburetor bowl, making it essential for any carburetor rebuild, restoration, or performance tuning project. Whether you're restoring a classic muscle car, servicing a street rod, or maintaining a high-performance engine build, a properly functioning needle and seat ensures consistent fuel level management and prevents lean-running conditions that compromise throttle response and engine reliability.

This adjustable needle and seat features a 0.150-inch orifice diameter and utilizes titanium construction for superior durability and corrosion resistance. The titanium material resists fuel degradation and varnish buildup that often plagues brass equivalents, extending service intervals and maintaining precise sealing geometry. The adjustable design allows tuning of fuel level in the bowl, accommodating different carburetor applications and fuel pressure requirements. Proper needle and seat installation ensures a tight seal that prevents fuel bypass into the float bowl, which would otherwise cause rich running conditions, fuel overflow, and performance loss.

Mechanics and engine builders working with Holley carburetors—particularly those servicing vintage imports, domestic performance vehicles, or competition engines—rely on quality needle and seat assemblies to achieve predictable tuning outcomes. Installation requires carburetor disassembly and careful seating to avoid damage to the delicate needle tip. This assembly is ideal for complete carburetor rebuilds, float bowl service, or fuel system troubleshooting when symptoms like fuel leaks, hard starting, or fluctuating idle suggest needle wear. Verify compatibility with your specific Holley carburetor model before ordering to ensure proper fit and performance.