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Sierra 18-0979 OMC 321183 Replacement Engine Gasket Marine

Manufacturer

Sierra

<h3>Sierra: Six Decades of Marine Aftermarket Excellence</h3><p><strong>Sierra</strong> has spent nearly 60 years earning its reputation as one of the most trusted names in the marine aftermarket industry. Originally focused on engine and drive components for boats, the brand has grown into a comprehensive source for nearly everything a boater needs to keep their vessel running at its best — from precision instrumentation to complete engine rebuild hardware.</p><p>Now operating as a brand of Dometic, Sierra manages global aftermarket distribution from a 300,000 sq. ft. facility in Litchfield, Illinois. The Sierra brand today encompasses not only its flagship marine parts line but also well-established marine names like Shields and Moeller, offering boaters a broader catalog than ever before. Whether you own an outboard, inboard, or sterndrive, Sierra's engineering team designs products to meet or exceed OEM specifications.</p><h3>Precision Instrumentation You Can Trust on the Water</h3><p>One of Sierra's most recognized product areas is its marine instrumentation lineup. The brand's <a href="/7570-sierra-gauge-set-1480">gauge sets</a> cover everything from classic analog instrument clusters to advanced digital multi-function displays. Sierra offers packages suited to outboards, sterndrives, and gasoline-powered inboards, with options ranging from coordinated analog kits in styles like Arctic, Eclipse, and Amega to modern touchscreen solutions like the R3 multi-function gauge. Features such as scratch-resistant domed glass lenses, silicone-dampened pointers, and perimeter backlighting make these instruments highly readable in all conditions.</p><p>Behind every accurate gauge reading is a properly calibrated sending circuit. Sierra's <a href="/7570-sierra-gauge-resistor-47908">gauge resistors</a> are a critical part of that chain, ensuring the signals from sensors and sending units are correctly interpreted by your instruments. These components are built to marine-grade standards to resist moisture, vibration, and corrosion — the realities of life on the water.</p><h3>Engine Internals Built to OEM Standards</h3><p>Sierra's history in marine power is perhaps best demonstrated by its deep catalog of engine components. The brand's <a href="/7570-sierra-engine-gasket-set-5404">engine gasket sets</a> cover a wide range of outboard and inboard applications and are engineered to deliver reliable seals in the demanding thermal and chemical environment of a marine engine. For boaters performing seasonal overhauls, top-end rebuilds, or full engine restorations, Sierra gasket kits are a go-to resource trusted by professional marine technicians and DIY boaters alike.</p><h3>A Complete Marine Parts Partner</h3><p>Beyond instrumentation and engine internals, Sierra's catalog spans fuel systems, electrical supplies, steering components, shore power, and more — all covered by what the brand calls an industry-leading warranty. Sierra also maintains a comprehensive parts-finder tool that enables cross-referencing with OEM part numbers from major manufacturers including Mercury, Yamaha, Suzuki, Volvo Penta, and others, making it straightforward to find the right replacement part for virtually any application.</p>

Part Number

18-0979
09/10/2036 2:50 PM
Sale Price

$12.92

2 left at this price

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Usually delivered within 2 days

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No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Sierra 18-0979 is a marine engine gasket designed as a direct replacement for OMC (Outboard Marine Corporation) original part number 321183. Sierra International is a trusted manufacturer of premium marine replacement parts, engineered to meet or exceed OEM specifications for reliability and performance on the water.

This gasket provides a precision seal for OMC outboard and sterndrive engines, helping to prevent fluid or gas leakage and maintain proper engine compression and performance. Sierra's gaskets are manufactured from high-quality materials selected to withstand the demanding thermal and mechanical conditions found in marine engine applications.

Key Features:

  • Direct OEM replacement for OMC part number 321183
  • Manufactured by Sierra International to meet or exceed OEM specifications
  • Designed for OMC outboard and sterndrive engine applications
  • High-quality materials for durability in marine environments
  • Helps maintain proper sealing, compression, and engine performance
  • Drop-in fitment for straightforward installation

Sierra part number 18-0979 is an ideal choice for marine technicians and DIY boaters looking for a reliable, cost-effective OEM alternative to keep their OMC-powered vessel running at its best.

Great so far.

great service

Good to go

easy navigation

fast ordering

Ordering was very easy and product was delivered within a week. I ordered a battery and it was received in good condition and works. I would recommend autoplicity to others.

Prompt and quick service... no hassle...

Very nice.

Thanks for having the part I needed, and at a really good price!

Good so far.

Quick and easy, shipping was expensive

I like how fast they ship and they have great prices. I will shop Autoplicity again. Thanks Guys

great price. here's to hoping for fast shipping.

What a great find! These people are very helpful and their prices are better than 4 wheel parts! The only thing I wish was improved was the handling time to be less than 4 days for 1 item, but other than that, I'm happy.

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