BB Fuel Pressure Regulator for Volvo Penta & Mercruiser 4.3/5.0/5.7 V6 — Direct-Fit OEM Replacement, Restores Fuel Pressure

BB Fuel Pressure Regulator is a direct-fit replacement part engineered to restore correct fuel pressure on Volvo Penta and Mercruiser 4.3L, 5.0L, and 5.7L engines.

This replacement regulator (compatible with Volvo Penta 3858967 and Mercruiser 2149831 / 885174 / 21491831) is designed for marine V6 gasoline engines that require consistent fuel delivery for reliable throttle response and engine performance. It matches OEM form and function for most 4.3, 5.0 and 5.7 applications, offering a straightforward swap when the original unit shows wear, leaks, or pressure drift. Note that this part is not intended for 8.1L engines.

How does this regulator affect engine performance on the water?

A properly functioning fuel pressure regulator keeps the fuel pressure within the range the engine and carburetor or fuel injection system expect, which helps maintain smooth idle, steady acceleration and predictable throttle behavior. Replacing a failing regulator reduces surging, hesitation and flooding risks caused by pressure irregularities. It’s a preventative upgrade when you notice inconsistent fuel delivery or when performing scheduled maintenance.

• Restores factory fuel pressure for responsive throttle control.
• Reduces risk of rich running or lean spots caused by incorrect pressure.
• Helps avoid fuel leaks and vapor lock from aging components.

Will this BB regulator fit my Volvo Penta 4.3, 5.0, or 5.7 engine?

This part is built to replace Volvo Penta part number 3858967 and Mercruiser references 2149831, 885174 and 21491831, so it fits most applications using those part numbers on 4.3L, 5.0L and 5.7L marine engines. Fitment is specific to those V6 platforms; it is not compatible with the larger 8.1L engines. Always verify the original part number and mounting pattern before installation.

• Direct replacement for Volvo Penta 3858967.
• Interchanges with Mercruiser 2149831, 885174, 21491831.
• Confirmed fit for most 4.3, 5.0, 5.7 V6 marine gasoline engines.

What should I check before and after installing the replacement regulator?

Before installing, inspect fuel lines, clamps and fittings for wear or deterioration and replace any brittle hoses. After installation, check for leaks at the inlet and return connections, verify correct fuel pressure with a gauge while the engine is running, and ensure stable idle and smooth throttle transitions during sea trials.

• Replace cracked fuel hoses and corroded clamps prior to fitting.
• Use a fuel pressure gauge to confirm regulator output under load.
• Perform a leak and performance check during a controlled test run.

Why choose this BB replacement instead of a used OEM regulator?

New replacement regulators provide fresh diaphragms, seals and springs that eliminate age-related failure modes common in used units. BB’s replacement is manufactured to match the critical dimensions and pressure characteristics of the original, offering reliable service without the premium cost of a new OEM part. Choosing a new regulator lowers the chance of repeat failures and reduces downtime in season.

• New internal components avoid deterioration found in used parts.
• Cost-effective alternative to dealer-priced OEM assemblies.
• Engineered to match original pressure behavior for predictable results.

Who is this for: Boaters, marine technicians and DIY engine owners with Volvo Penta or Mercruiser V6 gasoline engines (4.3L, 5.0L, 5.7L) who need a reliable fuel pressure regulator replacement. Ideal when the original part number matches 3858967, 2149831, 885174 or 21491831 and when you want a new, direct-fit regulator to restore consistent fuel delivery and reduce in-season issues.