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Sierra 18-3114 Marine Water Pump Impeller Insert Cup for Mercury & MerCruiser

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

18-3114
08/04/2036 9:13 PM
Sale Price

$8.88

In Stock (6)

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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 18-3114 Marine Insert Cup is a precision-engineered water pump impeller cup designed as a direct replacement for Mercury Marine and MerCruiser outboard and sterndrive cooling systems. This insert cup works in conjunction with the water pump impeller to maintain proper coolant flow and protect your engine from overheating.

Key Features:

  • Durable, non-corrosive construction engineered to withstand harsh marine environments
  • Designed for use with the 18-3116 water pump housing
  • Meets or exceeds OEM standards for reliable, long-lasting performance
  • Direct drop-in replacement — no modification required

OEM & Cross-Reference Part Numbers:

  • Mercury Marine: 48752, 48752T
  • GLM: 12810
  • Mallory: 9-43502

Sierra is a trusted name in aftermarket marine parts, offering premium-quality replacements across thousands of marine applications. The 18-3114 insert cup is a recommended service item whenever the water pump impeller is replaced, helping to ensure a complete and reliable cooling system repair.

So I left a review already about autoplicity and it was before I even checked when it was going to be delivered. I was happy to see it was already shipped but even more excited and pleased to see that it was only going to take two days to get here! Scheduled for delivery tomorrow! Could not be any happier with this company!

Thank you, it's a good day for buyers.

greaat price

fast and great pricing

fine so far

It was simple.

will let you know it gets to my house

Great and easy

Very good website. Easy to use. found the parts i needed and the order process was very easy since i could just login using my amazon account. Very convenient. Received my parts in a week.

......

best pricing for the item plus no tax and free ground shipping.better deal of all the online retailers

Good price

Easy order placement, fast shipment

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