Fuelab 52502-1 525 Series In-Line Carbureted Fuel Pressure Regulator 4-12 PSI Black

The Fuelab 52502-1 is a CARB-compliant, adjustable in-line fuel pressure regulator from the 525 Series, purpose-built for carbureted applications. Engineered from billet aluminum with a military-grade anodized finish (MIL-A-8625, Type II), this regulator delivers precise, repeatable fuel pressure control in the 4–12 PSID range. Its signature in-line design—where the return port aligns with the inlet port rather than exiting from the bottom—makes it one of the most installation-friendly regulators available for tight engine bays.

The 52502-1 features a large seat configuration with a single -6AN inlet and a single -6AN return port, both in-line for a clean, compact plumbing run. The fine thread pitch adjustment allows for precise fuel pressure tuning, while the included 1/8" NPT gauge port (with plug) enables connection of an external fuel pressure gauge. A 1/8" NPT pressure reference port with barbed fitting is also included for manifold vacuum or boost referencing.

Key Features:

• In-line design with -6AN inlet and -6AN return port in-line for tight installation spaces
• Adjustable pressure range: 4–12 PSID — ideal for carbureted applications
• CARB-compliant construction
• Compatible with gasoline, diesel, methanol, and ethanol
• Billet aluminum body with anodize per military MIL-A-8625, Type II — black finish
• Fine thread pitch adjustment for precise pressure control
• Accepts port-style and non-port-style union fittings without interference
• 1/8" NPT gauge port with plug for external pressure gauge
• 1/8" NPT pressure reference port with barbed fitting included
• Versatile mounting bracket and stainless steel hardware included
• Backed by a limited lifetime warranty

The Fuelab 525 Series is available in multiple configurations spanning carbureted (as low as 1 PSID) through fuel-injected applications (up to 125 PSID), making the entire series a versatile platform for a wide range of performance builds.