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Sierra 118-9251 Outboard Maintenance Kit Mercury 75 90 115 HP Optimax 2-Stroke

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

118-9251
06/02/2036 3:06 AM
Sale Price

$328.99

In Stock (5)

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Usually delivered within 2 days

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No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Sierra 118-9251 is a comprehensive, all-in-one outboard maintenance kit engineered for Mercury 75, 90, and 115 HP Optimax 1.5L 2-Stroke outboard engines with serial numbers 1B227000 and up. Designed to simplify routine service, this kit delivers everything needed to keep your Mercury Optimax running at peak performance — all in a single, convenient package.

Sierra Outboard Engine Maintenance Kits provide a one-box solution for scheduled service intervals, replacing the need to source individual components separately. Each kit is packaged in a premium full-color Sierra branded box with clear labeling of all included components.

Kit Includes:

  • High-quality spark plugs — pre-gapped and ready for installation
  • Water pump kit — specifically engineered for this engine model
  • Thermostat — model-specific fit
  • Fuel filter — designed for Mercury Optimax 2-Stroke engines

Key Features:

  • Fits Mercury 75, 90, and 115 HP Optimax 1.5L 2-Stroke outboards (S/N 1B227000 and up)
  • All components are model-specific — no guesswork on fitment
  • Significant cost savings compared to purchasing parts individually
  • Sierra aftermarket parts meet or exceed OEM standards
  • Saves time by consolidating all routine service parts into one kit

The Sierra 118-9251 maintenance kit is the smart choice for boaters and technicians looking to streamline scheduled service on Mercury Optimax outboards. Sierra has a decades-long history as a trusted manufacturer of aftermarket marine engine parts, and this kit reflects that commitment to quality and reliability.

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Great customer service extremely fast shipping thanks

Great service, perfect fit and speedy delivery! I&rsquo;ll be back.

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