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Sierra 118-0971 Bypass Gasket for Johnson Evinrude Outboard Motors

Manufacturer

Sierra

<h3>Sierra Marine: Over 58 Years of Aftermarket Excellence</h3><p><strong>Sierra</strong> has built a reputation as one of the most trusted names on the water, bringing more than five decades of engineering expertise to the marine aftermarket. <a href="/7570-sierra">Sierra</a> is a globally recognized manufacturer with a rich 58-year history developing aftermarket engine and drive parts primarily for the marine industry — covering everything from inboard sterndrive applications to outboard engines across a huge range of makes and models.</p><p>In 2022, the Sierra brand underwent a significant expansion, broadening its portfolio to serve both the boating sector and select land-based applications. Today, Sierra encompasses its full core product lineup alongside well-established marine brands like Shields and Moeller, giving boaters a single trusted source for a comprehensive range of parts and supplies.</p><h3>Instrumentation Built for the Helm</h3><p>Sierra is perhaps best known for its industry-leading marine instrumentation. The brand offers one of the widest selections of <a href="/7570-sierra-gauges-200483">marine gauges</a> available in the aftermarket, spanning both analog and digital formats. Whether you need a replacement fuel level indicator, oil pressure gauge, water temperature monitor, or voltmeter, Sierra engineers these instruments to deliver accurate, reliable readings in demanding on-water conditions. All gauges are built to be water-resistant, UV-protected, and corrosion-resistant — critical traits in a saltwater or freshwater marine environment.</p><p>For boaters who want a coordinated helm setup, Sierra's <a href="/7570-sierra-gauge-set-1480">gauge sets</a> make it easy to monitor all key performance metrics in a cohesive, matched style. Available in a variety of series — from the classic Lido and Amega styles to more modern configurations — these multi-function sets cover everything from RPM and speed to fuel level and trim angle in a single package.</p><p>One of the most critical instruments on any vessel, the <a href="/7570-sierra-tachometer-gauge-1488">tachometer gauge</a> tells the operator exactly how hard the engine is working. Sierra's tachometer lineup spans a wide RPM range and is designed to interface with outboard, inboard, and sterndrive gas engines. With features like scratch-resistant lenses, perimeter lighting for night visibility, and compatibility with NMEA 2000 systems on select models, Sierra tachometers are a go-to upgrade or OEM replacement for serious boaters.</p><h3>Marine Engine Oils Formulated for the Water</h3><p>Beyond instrumentation, Sierra produces a full line of <a href="/7570-sierra-engine-oil-12138">marine engine oils</a> developed specifically for the rigors of boat engine operation. From 4-stroke FC-W certified oils to full synthetic and semi-synthetic blends in a range of viscosities, Sierra's lubricants are formulated to meet or exceed the requirements of leading marine engine manufacturers. Their engine oils are engineered to reduce friction and sludge buildup, provide maximum corrosion protection, and keep engines running cleanly — whether you're navigating coastal waters or freshwater lakes.</p><h3>Why Boaters Trust Sierra</h3><ul style="list-style:disc"><li>Over 58 years of marine aftermarket manufacturing experience</li><li>Products meet or exceed OEM standards across inboard, outboard, and sterndrive applications</li><li>Industry-leading warranty on instrumentation and parts</li><li>Comprehensive catalog spanning instrumentation, engine parts, fuel systems, and electrical supplies</li><li>Expanded brand portfolio including legacy names Shields and Moeller</li></ul>

Part Number

118-0971
09/12/2036 12:50 PM
Sale Price

$7.11

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Product Details

The Sierra 118-0971 is a high-quality bypass gasket engineered specifically for Johnson and Evinrude outboard motors. This precision-manufactured gasket provides reliable sealing for 25 HP and 35 HP OMC outboard marine engines, ensuring proper coolant flow and preventing leaks in the cooling system.

Key Features:

  • Durable, non-corrosive construction designed to withstand harsh marine environments
  • Precision-machined to perfectly match engine component mating surfaces
  • Meets or exceeds original equipment manufacturer quality standards
  • Hard-wearing gasket seal ensures long-lasting, reliable performance
  • Engineered to match the exact fit and function of the OEM gasket

Cross-Reference Information:

  • Replaces OEM Part Number: 319661
  • Interchangeable with: GLM 34340, Johnson/Evinrude 319661, OMC 319661

This replacement gasket is essential for maintaining proper engine cooling system performance. A damaged or deteriorated bypass gasket can lead to coolant leaks and reduced engine efficiency. Sierra Marine has been manufacturing premium aftermarket marine engine parts for over 50 years, providing boaters with dependable replacement components backed by an industry-leading warranty.

Items were as described and appear to work as intended. Have not test drove the car to make sure the ignition coils function under load/boost. They shipped from a reputable supplier so I am confident in the purchase.

Can&rsquo;t wait to receive the part. Great pricing all around, from part to shipping.

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