My Account
Shopping Cart

Sierra 18-0408 Outer Wear Plate for Yamaha Outboard Water Pump

Manufacturer

Sierra

<h3>Sierra: Six Decades of Marine Aftermarket Excellence</h3><p><strong>Sierra</strong> has spent nearly 60 years earning its reputation as one of the most trusted names in the marine aftermarket industry. Originally focused on engine and drive components for boats, the brand has grown into a comprehensive source for nearly everything a boater needs to keep their vessel running at its best — from precision instrumentation to complete engine rebuild hardware.</p><p>Now operating as a brand of Dometic, Sierra manages global aftermarket distribution from a 300,000 sq. ft. facility in Litchfield, Illinois. The Sierra brand today encompasses not only its flagship marine parts line but also well-established marine names like Shields and Moeller, offering boaters a broader catalog than ever before. Whether you own an outboard, inboard, or sterndrive, Sierra's engineering team designs products to meet or exceed OEM specifications.</p><h3>Precision Instrumentation You Can Trust on the Water</h3><p>One of Sierra's most recognized product areas is its marine instrumentation lineup. The brand's <a href="/7570-sierra-gauge-set-1480">gauge sets</a> cover everything from classic analog instrument clusters to advanced digital multi-function displays. Sierra offers packages suited to outboards, sterndrives, and gasoline-powered inboards, with options ranging from coordinated analog kits in styles like Arctic, Eclipse, and Amega to modern touchscreen solutions like the R3 multi-function gauge. Features such as scratch-resistant domed glass lenses, silicone-dampened pointers, and perimeter backlighting make these instruments highly readable in all conditions.</p><p>Behind every accurate gauge reading is a properly calibrated sending circuit. Sierra's <a href="/7570-sierra-gauge-resistor-47908">gauge resistors</a> are a critical part of that chain, ensuring the signals from sensors and sending units are correctly interpreted by your instruments. These components are built to marine-grade standards to resist moisture, vibration, and corrosion — the realities of life on the water.</p><h3>Engine Internals Built to OEM Standards</h3><p>Sierra's history in marine power is perhaps best demonstrated by its deep catalog of engine components. The brand's <a href="/7570-sierra-engine-gasket-set-5404">engine gasket sets</a> cover a wide range of outboard and inboard applications and are engineered to deliver reliable seals in the demanding thermal and chemical environment of a marine engine. For boaters performing seasonal overhauls, top-end rebuilds, or full engine restorations, Sierra gasket kits are a go-to resource trusted by professional marine technicians and DIY boaters alike.</p><h3>A Complete Marine Parts Partner</h3><p>Beyond instrumentation and engine internals, Sierra's catalog spans fuel systems, electrical supplies, steering components, shore power, and more — all covered by what the brand calls an industry-leading warranty. Sierra also maintains a comprehensive parts-finder tool that enables cross-referencing with OEM part numbers from major manufacturers including Mercury, Yamaha, Suzuki, Volvo Penta, and others, making it straightforward to find the right replacement part for virtually any application.</p>

Part Number

18-0408
09/12/2036 9:57 AM
Sale Price

$16.60

2 left at this price

delivery box

Usually delivered within 2 days

Authorize Seller Badge
No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Sierra 18-0408 Outer Wear Plate is a precision-replacement water pump component designed for Yamaha outboard engines. It serves as a direct replacement for Yamaha OEM part number 65N-44323-00 and is a key element of the water pump assembly in the lower unit cooling system.

The outer wear plate seats at the base of the water pump cartridge, protecting the impeller housing from abrasion and maintaining the tight tolerances necessary for efficient water flow. Replacing a worn or damaged wear plate during routine impeller service helps restore proper cooling performance and prevents premature wear on other pump components.

Key Features:

  • Direct replacement for Yamaha OEM part number 65N-44323-00
  • Engineered to meet or exceed OEM specifications for fit and performance
  • Commonly serviced as part of water pump repair kits including Sierra 18-4533
  • Compatible with Sierra water pump repair kits for Yamaha outboard applications
  • Backed by Sierra's limited lifetime warranty against defects in materials and workmanship

This wear plate is also listed in Sierra water pump kit 18-4533, which replaces Yamaha kit 65N-W0078-A0-00. For best results, replace the outer wear plate any time the impeller is serviced to ensure optimal sealing and cooling efficiency.

Just

Great site. But phone operators do not know anything about cars.

First time buyer

Price was way more reasonable then any other part site.

Ordered front & back WeatherTech Digital Fit floormats for my Tacoma, and they arrived 2 days later! Will definitely use again in the future.

Share icon
Return Policy
Returns are easy at Boatplicity

Not happy with a purchase? No problem. We've made returning items as easy as possible. And most purchases can be returned for free for 30 days. Learn more about our Returns Policy