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Sierra 18-0971 Bypass Gasket for OMC Johnson Evinrude Outboard Engines

Manufacturer

Sierra

<p>For nearly six decades, Sierra has established itself as one of the marine industry's most trusted names in aftermarket engine and drive parts. Founded as a specialized marine parts manufacturer, Sierra has grown into a comprehensive supplier of replacement components, instrumentation, and accessories for both recreational and commercial boating applications. Operating from their 300,000-square-foot distribution center in Litchfield, Illinois, Sierra serves boat owners and marine technicians worldwide with an extensive catalog of parts engineered specifically for the harsh saltwater environment.</p><h3>Marine Engine Excellence</h3><p>Sierra's reputation was built on delivering precision-engineered internal engine components and drive system parts that meet or exceed OEM specifications. Their <a href="/7570-sierra-engine-gasket-set-5404">engine gasket sets</a> provide critical sealing solutions for inboard and outboard motors, while their <a href="/7570-sierra-engine-complete-assembly-15341">engine complete assemblies</a> offer comprehensive replacement options for major overhauls. Each component undergoes rigorous testing to ensure reliability in demanding marine conditions, from corrosion resistance to temperature cycling performance.</p><h3>Instrumentation and Monitoring Systems</h3><p>Accurate instrumentation is essential for boat operators to monitor engine health and prevent costly breakdowns on the water. Sierra's comprehensive line of <a href="/7570-sierra-gauges-200483">gauges</a> includes everything from fuel pressure and temperature indicators to voltmeters and trim gauges, all designed with marine-grade materials that withstand vibration, moisture, and UV exposure. Their <a href="/7570-sierra-tachometer-gauge-1488">tachometer gauges</a> deliver precise RPM readings critical for optimizing engine performance and fuel efficiency. Supporting these instruments, Sierra's <a href="/7570-sierra-gauge-resistor-47908">gauge resistors</a> ensure proper signal conditioning and accurate readings across various sensor types and engine configurations.</p><h3>Expanded Product Portfolio</h3><p>In 2022, Sierra significantly broadened its scope beyond traditional marine engine parts to encompass a wider range of boating accessories and even outdoor power equipment components. This strategic expansion brought established marine brands like Shields and Moeller under the Sierra umbrella, creating a one-stop resource for marine maintenance and replacement parts. The company now offers fuel systems, electrical components, battery charging solutions, and NMEA electronics alongside their traditional engine parts lineup.</p><h3>Quality Backed by Industry-Leading Warranties</h3><p>What sets Sierra apart in the crowded aftermarket marine parts market is their commitment to standing behind every component they manufacture. Their warranty coverage extends beyond simple part replacement—it includes shop labor, haul-out fees, towing charges, and related incidental costs should a warrantied part fail. This comprehensive protection reflects the company's confidence in their manufacturing processes and quality control standards. For boat owners facing repairs far from shore or mechanics working on customer vessels, this peace of mind is invaluable. Whether you're maintaining an outboard motor, rebuilding an inboard engine, or upgrading your boat's instrumentation, Sierra's decades of marine industry experience and commitment to quality make them a reliable choice for keeping your vessel running at peak performance.</p>

Part Number

18-0971
07/13/2036 3:08 PM
Sale Price

$11.84

In Stock (7)

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Usually delivered within 2 days

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Fitment guaranteed

Product Details

The Sierra 18-0971 is a replacement bypass gasket engineered for Johnson and Evinrude outboard engines. Designed as a direct replacement for OMC OEM part number 319661, this gasket restores proper cooling water flow management within the powerhead cooling circuit on 25 and 35 HP two-cylinder outboard motors.

As a Sierra International product, the 18-0971 is manufactured to meet or exceed the original equipment specifications it replaces, ensuring a reliable, leak-free seal. This gasket is also a component of the Sierra 18-4307 Powerhead Gasket Set, making it a convenient standalone replacement when only the bypass gasket requires service.

Key Features:

  • Direct replacement for OMC OEM part number 319661 (also referenced as 0319661)
  • Designed for Johnson and Evinrude outboard applications
  • Interchangeable with GLM part number 34340
  • Meets or exceeds original equipment manufacturer specifications
  • One gasket included per package

Cross-Reference Part Numbers:

  • OEM: OMC / Johnson / Evinrude 319661, 0319661, 777464
  • GLM: 34340
  • Recmar: REC0319661

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efficient.

Fast shipping, good prices, very satisfied with purchase.

Quick, efficient, professional

great so far

quick simple and the ability to check out through Amazon is a plus

Cheapest price by far, not the speediest shipment unfortunately.

Ordering was easy and hoping it ships as fast. Price was great.

Good prices !

Quality products, reasonable prices, product was delivered as promise, part fit perfectly. I would definitely put this organization in my top 3 best .

the amazon payment did not work; hope I don't get double billed since I went with paypal afterwards. Meanwhile, I could not verify that my amazon order is cancelled/never placed.

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