Fuelab 55501-4 555 Series Carbureted Blocking Fuel Pressure Regulator 4-12 PSI Purple

The Fuelab 55501-4 is a precision-engineered, blocking-style (non-bypass) adjustable fuel pressure regulator designed for carbureted applications. Purpose-built to deliver consistent, reliable fuel pressure, this regulator is adjustable from 4–12 PSI and is compatible with gasoline, diesel, methanol, and E85 ethanol fuels.

Key Features:

• Advanced poppet valve design for smooth, stable pressure regulation
• No-creep soft seat construction — fully compatible with methanol and E85 ethanol
• Billet aluminum body with military-grade anodize finish per MIL-A-8625, Type II
• Fine thread pitch adjustment for precise pressure setting
• (1) -8AN inlet port and (2) -8AN outlet ports with large seat design
• 1/8" NPT gauge port with plug included for optional external fuel pressure gauge
• 1/8" NPT breather vent port
• Versatile mounting bracket and stainless steel hardware included
• CARB-compliant design
• Backed by a limited lifetime warranty

The 555 Series is Fuelab's blocking-style regulator platform, making it ideal for dead-head fuel system setups common in carbureted and single-stage nitrous applications. The purple anodized finish (suffix -4) provides a distinctive appearance while offering durable corrosion protection.