857005A1 Mercury MerCruiser 21857005A1 Diaphragm Kit Fuel Pump | Genuine Quicksilver OEM Part

🔧 Product Description

Genuine Quicksilver Fuel Pump Diaphragm Kit - Part Number: 21-857005A1

A genuine Quicksilver fuel pump diaphragm kit for selected Mercury and Mariner 2-stroke outboards. This kit services the diaphragm-style fuel pump used to draw fuel from the tank and deliver it to the carburettor or fuel system at the correct pressure.

⚙️ Key Features

• Genuine Quicksilver OEM fuel pump diaphragm kit

• Correct Mercury part number 21-857005A1

• Replaces earlier 21-42990A10 diaphragm kit reference

• Used across selected 30 Jet through 225HP Mercury / Mariner outboards

• Helps restore fuel pump pressure and reliable fuel delivery

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• 21-857005A1 → Supersedes 21-42990A10

• 42990A11 related earlier diaphragm reference

• 42990A10 earlier OEM reference

OEM / Related Numbers:

• 21-857005A1

• 857005A1

• 21857005A1

• 21-42990A10

• 42990A10

• 42990A11

Aftermarket / Verified Equivalents:

• Recmar: REC21-42990A10

• No additional aftermarket equivalent

🚤 Compatibility

Commonly used on:

• Mercury / Mariner diaphragm fuel pump applications

Typically suits:

• Engine models:

• Mercury 30 Jet applications using diaphragm kit 21-857005A1

• Mercury 45 Jet - serial 0D000750 to 0G290584

• Mercury 65 Jet applications using diaphragm kit 21-857005A1

• Mercury 105 Jet applications using diaphragm kit 21-857005A1

• Mercury 140 Jet applications using diaphragm kit 21-857005A1

• Mercury 30HP 2-cylinder fuel pump applications

• Mercury 40HP 2-cylinder fuel pump applications

• Mercury 40HP 3-cylinder fuel pump applications

• Mercury 40HP 4-cylinder fuel pump applications

• Mercury 50HP 3-cylinder fuel pump applications

• Mercury 55HP 3-cylinder fuel pump applications

• Mercury 60HP 3-cylinder fuel pump applications

• Mercury 75HP 3-cylinder fuel pump applications

• Mercury 90HP 3-cylinder fuel pump applications

• Mercury 100HP 4-cylinder fuel pump applications

• Mercury 115HP 4-cylinder fuel pump applications

• Mercury 125HP 4-cylinder fuel pump applications

• Mercury V-135 fuel pump applications

• Mercury V-200 fuel pump applications

• Mercury XR-6 fuel pump applications

• Mercury 200 DFI applications where 21-857005A1 is specified

• Mercury 225HP 3.0L carbureted / EFI / SeaPro applications where specified

• HP Range: 30 Jet through 225HP where specified

• Engine Type: Mercury / Mariner 2-stroke outboard

• System Type: Diaphragm fuel pump repair kit

🔌 Function

The diaphragm kit renews the flexible fuel pump diaphragm and related components so the pump can draw and deliver fuel correctly.

Common signs of failure:

• Hard starting

• Engine stalls or hesitates under load

• Fuel starvation at higher RPM

• Fuel leaking from the pump body

• Cracked, stiff or torn diaphragm during service

📦 Condition

• Genuine Quicksilver part

• Brand new

• Supplied in original or equivalent packaging