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Sierra 18-3673 Thermostat Kit for Johnson/Evinrude V4 V6 Crossflow 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

18-3673
06/01/2036 1:58 PM
Sale Price

$40.80

4 left at this price

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Usually delivered within 2 days

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No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Sierra 18-3673 Thermostat Kit is a complete cooling system service kit designed for Johnson and Evinrude V4 and V6 Crossflow outboard engines. This comprehensive kit includes all the essential components needed to service your outboard's thermostat system in one convenient package.

Kit Includes:

  • Thermostat
  • Thermostat cover gasket
  • Thermostat gasket
  • Grommet (V4 Crossflow)
  • Poppet relief valve (V4 Crossflow)
  • Valve spring (V4/V6 Crossflow)

Proper thermostat function is critical for maintaining optimal engine operating temperature and preventing overheating. This Sierra kit provides OEM-quality replacement components to restore reliable temperature regulation to your outboard's cooling system. Regular thermostat maintenance helps extend engine life and ensure consistent performance on the water.

Application: Fits Johnson/Evinrude V4 and V6 Crossflow outboard engines

Been good although I never got a response about the wrong gaskets in my last order.

I hope it fits properly

Great price and fast shipping! Tech support helped me before the sale to make sure I was ordering the right part

very good

Easy to find and price was good. The product fit well. Works well so far

Quick shipping, and great prices. Thanks Autoplicity!

Easy to order!

Easy transaction.

Quick and easy checkout process...

i was skeptical about this site but after reading the reviews and them having the lowest price i could find for my part i pulled the trigger and wasn't disappointed. fast shipping and low prices with great customer service will shop with them again if they have what im looking for.

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