Manufacturer
<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>
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The Sierra 18-99121 is an aftermarket replacement intake manifold gasket designed to meet or exceed OEM specifications for compatible Yamaha outboard engines. This gasket serves as a direct replacement for Yamaha OEM part number 6G8-13646-A0, ensuring a reliable, leak-free seal between the intake manifold and the engine block.
Key Features:
Sierra International has been a leading supplier of marine replacement parts for decades, producing components that match OEM form, fit, and function. The 18-99121 intake gasket is an ideal choice for technicians and boat owners performing intake manifold service or top-end engine rebuilds on compatible Yamaha outboard motors.
Product came just three days after I ordered it! Great product at a great price. I would definitely order from them again!
rwb67c
easy , good price, instant 20% discount freight, hopefully will fit my 1985 chevy el camino v6 4.3 liter and delivered on time. thank you
roberto liwanag
Easy shopping and fast checkout, but this isn't the part I needed...
Veronica
great price
Glen A Pedersen
great selection at reasonable price.
Joel Dennis
Thanks
lori reed
So far its been fast and easy. I only hope the box comes undamaged. It looks like a nice box. Arrived with a little cardboard damage from UPS. The toolbox had some minor dents that I successfully pounded out. Was no fault of yours. Thanks.
Rick Prentice
Thank you.
Tyler Wise
Very competive prices, even with shipping costs. Looking forward to using Autoplicity again in the near future.
dancoiv
best price i found online
david damelio
thanks
mesut demiralp
I ordered the product and it was shipped very quickly and arrived safe and sound. I am very pleased with the transaction. Thanks!
Axonrus
Item arrived promptly (4 days after order), price was good and item was as described.
phoenixy1
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