Billet Bypass Fuel Pressure Regulator 4.5-9psi Adjustable Black 3/8" NPT Ports

Aeroflow’s Billet Bypass Fuel Pressure Regulator is engineered for carburettor systems, delivering precise, adjustable fuel pressure from the pump to the carburettor. Built around a durable black billet aluminium body with a bottom return, this regulator keeps your fuel pressure stable across the line for consistent performance and drivability.

Key benefits

• Precise, adjustable fuel pressure from 4.5 to 9 PSI ensures optimal needle and seat function and reduces flooding in carburettor setups.
• Bottom return design minimizes pressure spikes, improves cold-start performance, and helps regulate fuel flow back to the tank for smoother operation.
• Billet aluminium construction offers excellent heat resistance and long-term durability in demanding conditions.
• Compact dimensions with 3/8" NPT ports simplify installation in tight engine bays and custom builds.

Design and construction

• Finish: Black anodised billet aluminium body.
• Ports: 3/8" NPT with bottom return.
• Overall dimensions: Length 70 mm; Body height 59 mm; Bracket height 42 mm; Overall width 38 mm; Bracket centre-to-centre 43 mm.
• Finish options available include blue, black, red anodised or polished.

Specifications at a glance

• Adjustment range: 4.5–9 PSI
• Application: Carburettor systems with return line
• Performs with pump fuels, including E85 alcohol and diesel fuels
• Note: Recommended for Carburettor fuel pumps only – not EFI

Compatibility & installation considerations

• Designed specifically for carburettor fuel pumps and systems that include a return line to the tank.
• Not suitable for EFI applications.
• 3/8" NPT fittings provide a straightforward integration into common carburettor fuel plumbing.

Why choose this bypass regulator

• Maintains steady fuel pressure to the carburettor, protecting needle and seat assemblies from excessive pressure and improving overall drivability.
• Continual pressure regulation with a return path reduces pump load, delivering quieter operation and cooler fuel for longer pump life.
• Robust billet aluminium construction paired with a compact footprint makes it a practical upgrade for performance and classic builds alike.