Name: Fuel Pump Diaphragm Kit for Mercury Mariner Outboard Sport Jet 857005A1 18-7817
Brand: 4Boats
SKU: 21-857005A1
Price: 21.99 GBP
Availability: InStock

Fuel Pump Diaphragm Kit for Mercury Mariner Outboard Sport Jet 857005A1 18-7817

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£21.99

Tax included.

Fuel Pump Diaphragm Kit 857005A1

Premium Quality Replacement for Mercury & Mariner Outboards

Is your outboard engine hesitating, stalling, or struggling to start? This 12-piece fuel pump diaphragm rebuild kit is designed to restore consistent fuel delivery and engine response. Engineered to meet or exceed original equipment standards, this kit provides a cost-effective solution to common fuel system issues caused by worn or stiffened diaphragms.

RELIABILITY: Manufactured with marine-grade materials to withstand ethanol-blended fuels and harsh saltwater environments.

Key Features

✔ Direct fit for Mercury/Mariner 30HP-250HP
✔ Complete 12-piece rebuild kit
✔ Corrects hard starting and rough idling
✔ High-grade ethanol-resistant diaphragms

Technical Specs

Kit Contents:	12 Pieces
Includes:	Diaphragms, Gaskets, Valves, Spring, Screws
Engine Type:	2-Stroke Outboard / Sport Jet
Material:	Viton/Marine Grade Gasket Material

Compatibility / Fitment Guide

Engine Series	Horsepower / Models	Note
Mercury/Mariner 2-Stroke	30HP, 35HP, 40HP, 45HP, 50HP, 55HP, 60HP	Check Serial Range
Mercury/Mariner 2-Stroke	75HP, 90HP, 100HP, 115HP, 125HP	3 & 4 Cylinder Models
Mercury V-Block	V-135, V-150, V-175, V-200, V-225, V-250	Carbureted & EFI
Mercury Sport Jet	90, 95XR, 120, 175XR2	Jet Drive Pump

OEM Cross Reference

Mercury / Quicksilver:	857005A1, 21-857005A1
Sierra Marine:	18-7817
GLM:	40290
Mallory:	9-35430

Questions & Answers

Is this a genuine original part?

This is a premium quality aftermarket replacement part, manufactured to meet or exceed original equipment (OE) standards for fitment and performance on Mercury engines.

How do I know if it is compatible?

We recommend checking the SKU/MPN and Cross Reference list provided above. This kit specifically fits Mercury/Mariner 2-stroke engines that utilize a diaphragm-style fuel pump.

Will this fix my engine's stalling issues?

If your engine stalls due to fuel starvation or a loss of fuel pressure, a worn or torn diaphragm is often the cause. This kit replaces those critical components to restore proper suction and pressure.

Note: Please verify your original part number or engine serial number against the references above before purchasing. Domain: 4boats.co.uk

For the products under £150 the shipping is £6.99.

Free delivery for most items over £150.

Why choose us

QUALITY MARINE PARTS

We source dependable marine products from established suppliers and continually refine our range using customer feedback.

TRUSTED SUPPLIERS

We work with trusted marine suppliers and distribution partners to provide reliable parts, equipment and fulfilment.

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PERSONAL SERVICE

Every order is checked by the 4Boats team. Contact us before ordering if you need help with part numbers, compatibility or availability.

Fuel Pump Diaphragm Kit for Mercury Mariner Outboard Sport Jet 857005A1 18-7817