Description

The Mercury MerCruiser Quicksilver 27-42457 is a genuine Mercury Marine OEM fuel pump mounting plate gasket used on select GM-based MerCruiser V6 sterndrive engines. This gasket seals the fuel pump mounting plate area at the engine block where the factory parts diagram calls for 42457 / 27-42457. It is typically used during mechanical fuel pump, fuel pump plate, or side-block sealing service on compatible carbureted MerCruiser applications.

Key Features

• Genuine Mercury Marine factory OEM gasket.
• Mercury/MerCruiser part number: 27-42457.
• Manufacturer part number: 42457.
• Official part label: GASKET.
• GTIN/UPC: 745061074156.
• Listed shipping weight: 0.02 lb.
• Listed shipping dimensions: 4.25 in. L x 2.58 in. W x 0.25 in. H.
• Used where the Mercury/MerCruiser engine parts diagram calls for this gasket at the fuel pump mounting plate or related block-mounted fuel pump area.

Engine Compatibility

Common where-used MerCruiser application groups include select:

• 175 2-Barrel GM 262 V6 — 1987, serial range 0B527955 thru 0B773242
• 185 2-Barrel GM 262 V6 — 1985–1987, serial range 0A331455 thru 0B527954
• 185 4-Barrel GM 229 V6 — 1983–1984, serial range 6330183 thru 6919655
• 205 4-Barrel GM 262 V6 — 1985–1987, serial range 0A331455 thru 0B527954
• 205 4-Barrel GM 262 V6 — 1987, serial range 0B527955 thru 0B775129
• 4.3L 2-Barrel GM 262 V6 — 1988–1992, serial range 0B773243 thru 0D714106
• 4.3LX 4-Barrel GM 262 V6 — 1988–1992, serial range 0B775130 thru 0D714369

Use this gasket only where the Mercury/MerCruiser parts diagram specifically calls for 27-42457 / 42457.

Serial Number Fitment Notice

Confirm fitment by engine serial number, carburetor configuration, and exact fuel pump or mounting plate diagram before ordering. Similar GM-based MerCruiser V6 engines can use different fuel pump gaskets, adaptor gaskets, mounting plates, and related hardware depending on model year and serial range.

When This Part Needs Replacement

Replace this gasket whenever the fuel pump mounting plate, mechanical fuel pump, or related block-mounted cover is removed. It should also be replaced if there is oil seepage, fuel pump area leakage, gasket swelling, cracking, hardening, tearing, or residue around the side of the engine block. Reusing an old compressed gasket can lead to repeat leaks after service.

Installation Notes

Clean the engine block and mounting plate surfaces before installation, removing old gasket material without gouging the sealing faces. Inspect the fuel pump mounting plate, fasteners, fuel pump pushrod area, and nearby fittings while the assembly is apart. Do not substitute a generic gasket material unless the service manual specifically supports it. Follow the MerCruiser service manual for the correct installation procedure and torque sequence for the engine model.

Alternate/Superseded Part Numbers

• 27-42457 — Mercury/MerCruiser formatted part number
• 42457 — Manufacturer part number

Parts Desk Insight

This gasket is often replaced during fuel pump or block-off plate service because the sealing surface is disturbed as soon as the plate is removed. Matching the gasket by Mercury part number and engine serial range helps avoid small shape or hole-location differences that can cause oil seepage or an improper seal.

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