My Account
Shopping Cart

Sierra 18-3366 Marine Water Pump Impeller for OMC Johnson Evinrude Outboards

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

18-3366
08/05/2036 12:58 AM
Sale Price

$14.68

In Stock (6)

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 18-3366 is a neoprene water pump impeller designed as a direct replacement for OMC, Johnson, and Evinrude outboard motors. Built to meet or exceed original equipment standards, this impeller keeps your engine's cooling system operating efficiently by maintaining proper water flow through the water pump.

Key Features:

  • 6-blade neoprene construction with brass hub for durability and reliable performance
  • OEM-quality replacement — manufactured to meet or exceed original equipment specifications
  • Direct replacement for OMC OEM part numbers 390286 and 777835
  • Outer diameter: approximately 2.004 inches
  • Hub/shaft size: 0.689 inch
  • Blade depth/height: 0.748 inch
  • Compatible with aftermarket cross-references: Mallory 9-45212, GLM 89990, SEI Marine 96-399-05E, CEF 500353

Regular impeller replacement is a critical part of outboard motor maintenance. A worn or damaged impeller can lead to overheating and serious engine damage. The Sierra 18-3366 makes it easy to restore full cooling system performance with a quality aftermarket part you can trust.

YOU HAD EXACTLY WHAT I NEEDED QUICKLY

Excellent pricing for the autovent shade I ordered. Quick and easy check out thru Amazon payments. Shipped out within 2 days. I would order from them again!

Awesome price! I couldn't find a better bargain anywhere, and I searched for days.

The best price I could find and it arrived in 2 days! I'll be doing business again.

The only recommendation I have is to include the position in the description for brake pads. I had to check another site to verify front vs. rear pads. It's not a major issue, especially because you have some of the best prices on these pads.

I was hesitant to order from Autoplicity due to the perception that the price was too good to be real (and not some scam). However, I read a few reviews on the internet and decided to take a chance. Once I placed my order I was sent a tracking number and received my car parts within 2 weeks. I was happy that I got the parts I ordered and the price was really low. Simple and quick.

Easy store to navigate through and had all the info.

Ordered the Auto Ventshade Ventvisor Deflector 4 pc. (Model 94856) for my 2000 Toyota Camry XLE. Was easy to install with no tools, just use the included strong double sided adhesive tape. Instructions that came with it could've been more detailed on where exactly to install the ventshade as I had to remove them tediously, realizing I had to put them a little higher. Also, there seems to be an unsightly gap between the front and back windows. Works as designed. Satisfied with product. Fast shipping by Autoplicity.

Easy to navigate and shipping cost reasonable.

So far so good

Great Service

I ordered this Weathertech cargo liner (order#: 8049) on a Tuesday and received it by Saturday. Speedy delivery and absolutely love this product. It is a perfect fit and still easy to get to the storage compartment of my Rav4.

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