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Sierra 18-1906 3-Inch Exhaust Manifold Riser Spacer for MerCruiser Stern Drives

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

18-1906
07/11/2036 3:33 PM
Sale Price

$141.97

2 left at this price

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Usually delivered within 2 days

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Product Details

The Sierra 18-1906 is a 3-inch exhaust manifold riser spacer designed for MerCruiser stern drive applications. This spacer installs between the exhaust manifold and the riser elbow, providing additional height to help prevent water from traveling back into the riser when throttling down, and can provide added clearance for exhaust hose routing.

Built to Sierra's high quality standards, this spacer features durable, non-corrosive construction and CNC-machined mating surfaces for a reliable seal without additional preparation. Sierra uses special casting techniques to ensure uniform wall thickness, and each spacer is leak-tested prior to painting for added quality assurance.

Key Features:

  • 3-inch (76.2 mm) exhaust manifold riser spacer
  • Durable, non-corrosive construction
  • CNC-machined mating surfaces for leak-free installation
  • Primed and painted for corrosion resistance
  • Leak-tested prior to paint for quality assurance
  • Direct OEM replacement — installs ready out of the box

Compatible With (Sierra Part Numbers):

  • 18-1950 Manifold
  • 18-1951 Manifold
  • 18-1958-1 Manifold
  • 18-1962-1 Manifold
  • 18-1971 Elbow
  • 18-1978 Elbow
  • 18-8554 Exhaust Elbow Mounting Kit

Replaces These Part Numbers:

  • MerCruiser Stern Drive: 61851A1
  • Barr: MC-20-61851A2
  • GLM: 50330
  • Mallory: 9-40532
  • Osco: 1851

Great

Very easy &amp; quick.

good

very good

The best prices on the net.

this was a quick and easy order, although they came up in free shipping, i was charged for shipping. BUT, they were the least expensive for what i ordered on the entire web. thanks for being the lowest price!!!

Quick and easy checkout

So far so good

great prices with easy searching.

Great price on the Defi gauges that I wanted. I placed my order at 2 PM and asked if it could be shipped that day. Said that they would do their best. Shipped that same day. UPS 2 day day is only taking one day to Noerthern Virginia.<br><br>Great Prices and really fast shipping. Keep up the good work.

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