Fuel Pump Diaphragm Kit – Fits Mercury/Mariner V200 V225 Outboard (Replaces 90363A1)

$19.99 $31.00

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Product Details

This Fuel Pump Diaphragm Kit – Fits Mercury/Mariner V200 V225 Outboard (Replaces 90363A1) is designed for rebuilding mechanical fuel pumps on Mercury and Mariner V200 and V225 outboard engines. It provides the essential components to restore fuel pump performance and prevent leaks.

This kit serves as a direct replacement for Mercury/Quicksilver 90363A1, Sierra 18-7810, and GLM 40390.

Installation Method: Direct replacement of internal components.
Primary Function: Mechanical fuel pump diaphragm kit for gasoline engines.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand	Part Number
Mercury/Quicksilver	90363A1
Sierra	18-7810
GLM	40390

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Mercury and Mariner models, this kit is specified for V200 and V225 engines using the listed OEM part number.

Brand	Model	Rated HP	OEM Part No.
Mercury	V200	200	90363A1
Mercury	V225	225	90363A1
Mariner	V200	200	90363A1
Mariner	V225	225	90363A1

Technical Specs

Product Type: Fuel Pump Diaphragm Kit
Installation: Direct replacement
Fuel Type: Gasoline
Dimensions: 1.5" H x 7.5" W x 6.0" L
Other Technical Attributes: Mechanical fuel pump diaphragm kit

What’s in the Box

Diaphragm(s)
Gasket(s)
Spring(s)
Other components

Installation Notes

Disconnect the battery and relieve any pressure in the fuel system for safety.
Carefully disconnect the fuel inlet and outlet lines from the fuel pump. Note their orientation.
Remove the mounting bolts securing the pump to the engine block and detach the old pump.
Disassemble the pump housing to access the internal diaphragm, gaskets, and springs.
Remove the old diaphragm and its related components. Dispose of them properly.
Thoroughly clean all housing surfaces, ensuring no old gasket material remains.
Install the new diaphragm, gaskets, and springs from the kit as per the original's orientation.
Carefully reassemble the pump housing, ensuring a tight seal. Torque bolts to manufacturer specifications if available.
Reinstall the pump onto the engine, reconnect the fuel lines, and ensure all fittings are secure.
Reconnect the battery, prime the fuel system, and carefully check for any leaks before starting the engine.

Troubleshooting & FAQ

How do I know if this diaphragm kit fits my engine?

This kit is specifically for Mercury and Mariner V200 and V225 outboards that use the OEM part number 90363A1. Always verify by comparing the part number and visually matching your old diaphragm to our product images.

What are the signs of a failing fuel pump diaphragm?

Common symptoms include the engine running rough, stalling, loss of power, or visible fuel leaking from the pump's weep hole. A torn diaphragm can also allow fuel to enter the crankcase, thinning the oil.

How often should a fuel pump diaphragm be replaced?

There is no fixed interval, but diaphragms degrade over time due to fuel additives (especially ethanol) and age. Consider a preventative replacement every 5-7 years or if you notice any performance issues.

Can I install this kit myself?

Yes, this is a common DIY task for those with mechanical experience. However, working with fuel systems carries inherent risks. If you are not confident, professional installation is strongly recommended for safety and reliability.

What is the difference between OEM and aftermarket parts?

This listing is an aftermarket replacement (not OEM). It has been built to OEM-level specifications with comparable materials. Our parts are manufactured in an ISO 9002 facility and are batch-inspected for consistency and quality.

How fast is shipping and what does it cost?

We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

What is the warranty and return policy?

This product is covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact our support team with your order details. Returns are accepted within our standard window for unused items in their original condition. Please see our policy page or reach out for instructions.

Safety & Important Info

Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
This is an aftermarket replacement, not an OEM component.
Professional installation is recommended for safety and performance.

About Sea Sierra

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Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

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