Holley Carbureted Bypass Fuel Pressure Regulator 4.5-9 PSI 12-803BP

Item #21923

Made in the USA
Holley Carbureted Bypass Fuel Pressure Regulator 4.5-9 PSI 12-803BP
Street/Strip Carbureted Applications
Two Port
Adjustable from 4.5 to 9 PSI
- +
Quantity: close


Holley fuel pressure regulators are designed to precisely control the fuel pressure from the fuel pump to the carburetor. Too much fuel pressure for a given needle and seat assembly can overload the needle and seat and may cause flooding or drivability problems. Each Holley fuel pressure regulator is fully adjustable so regulating the fuel pressure to your engines needs is a simple task. All Holley regulators are pre-set at the factory so there is no guesswork when first installing the regulator. The Holley 12-803BP fuel pressure regulator features 3/8" NPT in/out ports and a 3/8" NPT return port.


  • Adjustable fuel regulation from 4-1/2 to 9 psi
  • Preset to 7psi
  • 3/8” NPT ports (1 in, 1 out, 1 bypass or return)
  • Used in systems with a return line back to the fuel tank
  • Quieter fuel pump operation
  • Designed only for carburetor use
  • Polished finish
  • Mounting bracket included


(1)Holley Carbureted Bypass Fuel Pressure Regulator 4.5-9 PSI 12-803BP


Brand: Holley
Color: Shiny
Emission Code: 5
Fuel System: Gasoline
Inlet Size: 3/8 inch NPT
Material: Aluminum
Outlet Size: 3/8 inch NPT
Pressure Range: 4.5-9 PSI
Product Type: Fuel Pump
Return Size: 3/8 inch NPT
Style: Bypass
Part Number: 12-803BP

This part is legal for sale or use on Emissions Controlled Vehicles, Uncontrolled (Non-Emissions Controlled) Vehicles, and Racing Use Only Vehicles because it does not affect vehicle emissions and is not covered by emissions regulations.


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Instructions for Part# 12-803BP

Holley Fuel Systems Chart

***The 803BP is designed for use with an electric fuel pump with a return line in the system. If you are using a mechanical fuel pump, use the 12-803 regulator.


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