Description

Mercury MerCruiser Quicksilver 861126A1 is a genuine OEM fuel pressure regulator used on a range of MerCruiser MPI sterndrive and inboard engines. Mercury’s current product page identifies it as a fuel pressure regulator that mounts on the fuel cooler and is used on MerCruiser 4.3L, 5.0L, 5.7L, and 6.2L MPI engines with ECM 555, as well as 7.4L MPI (L29), 454 Magnum MPI, 496 Magnum and HO, 500 EFI, and 8.1S and HO applications.

Key Features

• Genuine Mercury MerCruiser OEM part number 861126A1.
• Officially identified as a fuel pressure regulator for MerCruiser MPI fuel systems.
• Mounts on the fuel cooler in the applicable fuel system layout.
• Current Mercury dealer references identify it as a 43 PSI regulator kit.
• Current dealer listing shows UPC / GTIN 745061448353.

Engine Compatibility

Current Mercury references support 861126A1 for MerCruiser 4.3L, 5.0L, 5.7L, and 6.2L MPI sterndrive and inboard engines with ECM 555, plus 7.4L MPI (L29), 454 Magnum MPI, 496 Magnum and HO, 500 EFI, and 8.1S and HO applications. Current dealer fitment references also describe it for MCM and MIE MPI installations in those same engine families.

Serial Number Fitment Notice

Verify fitment by exact engine serial number, fuel system layout, and service manual application before ordering. With 861126A1, the important check is the correct MPI / ECM 555 / fuel-cooler-mounted regulator setup, because similar MerCruiser fuel system parts can appear close while serving different pressure or mounting requirements.

When This Part Needs Replacement

This regulator is typically replaced when fuel pressure control becomes unreliable or when diagnosis points to a failed or weak regulator in the MPI fuel system. In practical service terms, issues such as poor running, hard starting, or fuel-pressure inconsistency can lead technicians to this part, but the exact diagnosis should always be confirmed against pressure testing and the service manual. This replacement guidance is a practical service inference based on the part’s documented role as the engine’s fuel pressure regulator.

Installation Notes

Install 861126A1 only after confirming the correct MerCruiser fuel system application for the engine being serviced. Current Mercury references state that the regulator mounts on the fuel cooler, and Mercury directs owners and technicians to the owner’s manual or service manual for exact application and installation instructions.

Alternate/Superseded Part Numbers

Current sources reviewed consistently show 861126A1 as the active OEM Mercury number. Dealer and aftermarket cross-reference sources also associate AM861126A1 and MAL9-33206 as related aftermarket references for this same regulator application.

Parts Desk Insight

The easy mistake with a fuel regulator like this is matching it only by engine size. For 861126A1, the better match is the exact MPI fuel system, ECM 555 setup, and fuel-cooler-mounted regulator layout, because that matters more than the displacement alone when you want the fuel system to perform the way it should.

Shipping: Ships same or next day for fast Canada wide shipping.