Gasket, Cap to Pump – Fits Mercruiser & OMC (Replaces 802303, 338876)

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Product Details

This Gasket, Cap to Pump – Fits Mercruiser & OMC (Replaces 802303, 338876) is designed for use between the fuel pump cap and pump housing on various Mercruiser and OMC/Evinrude/Johnson marine engines. It creates a reliable seal to prevent fuel leaks within the fuel pump assembly.

It is a direct interchange for Mercruiser part number 802303, OMC part numbers 0338876/338876, and Sierra part number 18-2945-9.

Installs directly between the fuel pump cap and housing.
Compatible with gasoline engines.
Engineered to ensure a precise, leak-free fit on mating surfaces.

Part Number Matrix

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

Brand	Part Number
Mercruiser	802303
OMC	0338876
OMC	338876
Sierra	18-2945-9

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This gasket is confirmed to fit specific Johnson outboard models and is widely used across the OMC family.

This gasket is applicable to various Mercruiser sterndrive engine models.

Brand	Model	Rated HP	Years	OEM Part No.	Notes
Johnson	SJ10RPLB	10	1996	338876	Cap to pump gasket, part of fuel pump assembly
Mercruiser	Various			802303

Technical Specs

Product Type: Fuel Pump Gasket
Installation: Between fuel pump cap and pump housing
Fuel Type: Compatible with gasoline engines
Connection: Mating surface between components
Dimensions: 4.0" H x 5.13" W x 1.25" L
Fitting Type: Direct fit
Other Technical Attributes: Used with fuel pump assembly

What’s in the Box

1 x Gasket, Cap to Pump (338876/802303)

Installation Notes

Disconnect the battery and ensure the engine is completely cool before starting.
Relieve fuel system pressure according to the manufacturer's service manual to prevent spills.
Carefully remove the fuel pump assembly components that cover the old gasket.
Remove the old gasket. Thoroughly clean both mating surfaces to remove any residue or debris.
Position the new gasket, making sure it aligns perfectly with the mounting holes.
Reassemble the fuel pump cap and housing. Tighten all fasteners to the correct torque specified in your service manual.
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 gasket will fit my engine?

The best way to confirm fitment is to check your original part number against the ones listed in our Part Number Matrix. You can also review the Engine & Model Compatibility table. If you are unsure, please compare the pictures to your original part.

What are the signs of a failing fuel pump gasket?

Common signs include a visible fuel leak around the fuel pump, a strong smell of gasoline, poor engine performance, hesitation during acceleration, or difficulty starting the engine.

Can I reuse my old gasket or do I need a new one?

It is never recommended to reuse a fuel pump gasket. Gaskets compress to create a seal and will not provide a reliable seal if re-installed. Always use a new gasket when servicing the fuel pump.

Is any sealant required with this gasket?

Generally, no additional sealant is required for this type of gasket. It is designed to create a seal on its own. Applying sealant can sometimes interfere with proper sealing. Always follow the instructions in your engine's service manual.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost?

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

Warranty & returns?

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). 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

Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
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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