Genuine Mercury / Quicksilver Fuel Pump Diaphragm Kit — 12-Piece

Part Number: 857005A1 (also catalogued as 21-857005A1)

Type: Fuel Pump / Carburetor Diaphragm Rebuild Kit — 12 pieces

What Does This Kit Do?

The 857005A1 is a genuine Mercury / Quicksilver OEM 12-piece service kit used to rebuild or repair the mechanical fuel pump and carburetor diaphragm assembly on 2-stroke outboard motors. The kit restores proper mechanical vacuum pressure within the pump to maintain uniform, consistent fuel delivery to the carburetors.

Kit Contents (12 Pieces)

Includes: fuel pump diaphragms, sealing gaskets, check valves, a tension spring, a cap, and assembly screws.

Common Symptoms Addressed

Servicing the pump with this kit helps correct:

• Rough idling or engine hesitation
• Loss of top-end power
• Hard-starting
• Poor fuel delivery caused by a stiff, torn, or stretched diaphragm

Compatibility

Primarily engineered for Mercury and Mariner 3-cylinder 2-stroke outboards ranging from 30hp to 65hp, including:

• 45 Jet — Serial No. 0D000750 through 0P016999
• 50hp — 3-Cylinder models
• 55hp — 3-Cylinder models
• 60hp — 3-Cylinder models

Note: Can also cross-reference onto select vintage Force outboard configurations using specific mechanical fuel pump blocks.

Not sure if this fits your engine? Contact us with your engine serial number and we'll confirm compatibility for you.

Aftermarket Cross-References

• Sierra Marine: 18-7817
• Red Rhino / OBR: FM-803
• GLM: 40290

Why Buy From Warragul Marine?

• Genuine Mercury / Quicksilver OEM parts — not aftermarket
• Fast dispatch from our Australian warehouse