My Account
Shopping Cart

Sierra 18-3090 Water Pump Impeller for Johnson/Evinrude Outboard Motors

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

18-3090
09/12/2036 7:38 AM
Sale Price

$18.26

In Stock (10)

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 18-3090 is a premium replacement water pump impeller designed for Johnson and Evinrude outboard motors. This critical cooling system component ensures proper water circulation through your engine to prevent overheating and maintain optimal performance.

Key Specifications:

  • 6-blade neoprene impeller construction
  • Outer diameter: 1.52 inches (38.27mm)
  • Thickness: 0.72 inches (18.12mm)
  • Bore diameter: 0.44 inches (11.20mm)
  • Designed for use in plastic pump housings

Applications:

  • Johnson/Evinrude 1.2HP, 2HP, 4HP, and 6HP outboard motors
  • Specific fitment for 2HP (1985-1990), 4HP (1976-1980 with 90-degree gearcase), and 6HP (1979) models

OEM Cross References:

  • Johnson/Evinrude: 387361, 763735, 777831
  • Mallory Marine: 9-45210
  • GLM: 89490

Sierra products are engineered to meet or exceed OEM standards and are built to withstand harsh marine environments. Each Sierra impeller is backed by a limited lifetime warranty covering defects in materials and workmanship.

Products specifications

Replaces

387361, 763735

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

Great experience.

Shipping is expensive

GREAT SERVICE, FAST SHIPPING, WILL USE AGAIN

quick and easy

Very easy search.

Easy.

FIRST TIME BUYER - WE'LL SEE HOW IT ALL GOES

I needed to verify the part was correct. The telephone staff was very helpful, professional and informed about your products.

SIMPLE & EASY

competitive prices and good selection. Will definitely look to this vendor when purchasing automotive parts in the future. I ordered a roof rack and it was very hard to find elsewhere and the few places I did find it, it was more expensive.. it was cheap and easy here. thanks :)

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