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Sierra 18-55506 Outboard Starter for Mercury Marine Engines

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

118-55506
09/12/2036 10:01 AM
Sale Price

$218.18

In Stock (7)

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Usually delivered within 2 days

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Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Sierra 18-55506 is a high-quality replacement outboard starter designed specifically for Mercury Marine engines. This reliable starter serves as a direct replacement for Mercury OEM part numbers 50-8M0088064 and 50-8M0137769, providing dependable performance at a competitive price point.

Enhanced Design Features:

  • Superior connection between the solenoid and commutator brushes for improved electrical efficiency
  • Updated planetary gear and clutch gear spring engineered to maximize lifespan and reliability
  • Advanced solenoid design utilizing higher quality materials for optimum performance
  • Extended battery terminal length for easier installation and improved connections
  • Strategically integrated seals to reduce water intrusion and protect internal components

Sierra marine starters are manufactured to meet or exceed OEM specifications, offering boaters and marine technicians a trusted aftermarket solution for Mercury outboard engine starting systems. The 18-55506 is part of Sierra's comprehensive line of marine electrical components designed for the harsh marine environment.

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Great service, only hiccup was I paid for 2 day shipping $9.99 Item took 5 days. I was credited the $9.99 No big deal, will order from boatplicity.com again!

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The carton for the unit looked as if the box gad sat in water for so.e time. But luckily did not effect the unit inside.

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No problems, everything came as ordered.

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