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Sierra 18-4274 Marine Propeller Spacer for Yamaha 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

118-4274
09/12/2036 5:57 AM
Sale Price

$26.38

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Product Details

The Sierra 18-4274 is a high-quality marine propeller spacer designed specifically for Yamaha outboard engines. This precision-engineered component ensures proper propeller alignment and spacing on the propeller shaft, providing smooth operation and optimal performance for your outboard motor.

Key Features:

  • Designed for Yamaha outboard motors, 115-300 HP applications
  • Direct replacement for OEM Yamaha part numbers 688-45997-00-00 and 688-45997-01-00
  • Meets or exceeds original equipment manufacturer specifications
  • Interchangeable with Mallory 9-73915 and GLM 22191
  • Includes one propeller spacer per package
  • Essential component for proper propeller installation and maintenance

Sierra is a trusted name in marine aftermarket parts with over 58 years of manufacturing excellence. This propeller spacer is commonly included in Sierra prop nut kits 18-3781 and 18-3782, and is recommended when replacing or servicing your propeller hardware. Proper propeller spacing is critical for preventing damage to the lower unit and ensuring safe, reliable operation of your Yamaha outboard engine.

Fast shipping and great product. Great price. Will recommend you to others.

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My order arrived on time. I've tire pressure sensor tool worked well.

I ordered a part for my RV furnace. You shipped it out in a reasonable time, but the part was delayed by the USPS and I received it almost a week after I ordered it. Since it was delayed & I could not wait for it, I got the same part from another place. After I received your part late, I called and requested a return. I was very satisfied with the return process & received notice yesterday that a refund had been issued. All in all, I was very satisfied with your service, but not with USPS.

I was not sure if the replacement pads for my Nerf bars would fit but I took placed the order. They showed up in a few days and were a perfect fit! Thanks!

Could not have been better! Very professional and very prompt with order and delivery! You can't go wrong with this company.

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