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Quicksilver 18643A5 Triangular Flywheel Mount Engine Coupler Kit MerCruiser Alpha Stern Drive

Manufacturer

Quicksilver

<h3>Quicksilver: The Marine Enthusiast&apos;s Trusted OEM Brand</h3><p>For boaters who refuse to compromise on quality, <strong>Quicksilver</strong> has been the benchmark for marine parts, accessories, and engine care products since 1950. Based in Fond du Lac, Wisconsin, Quicksilver operates as the parts and accessories brand of Mercury Marine — and that heritage is central to everything it makes. As the only marine aftermarket brand manufactured and recommended by an original-equipment manufacturer, Quicksilver brings factory-level engineering directly to boat owners, professional technicians, and weekend warriors alike.</p><p>What sets Quicksilver apart from generic aftermarket suppliers is its direct lineage to the engineers who designed the engines in the first place. Every component is engineered, tested, and manufactured with the same exacting standards as the original equipment it replaces. The result is a product line that fits right the first time and delivers the reliability boaters depend on — whether they&apos;re navigating calm inland lakes or pushing through demanding saltwater conditions.</p><p>Quicksilver&apos;s catalog spans more than 40,000 parts across 12 product lines, covering outboard and sterndrive engines from Mercury, Mariner, Yamaha, Honda, Evinrude, Johnson, Suzuki, and more. Among the most critical components in that lineup are Quicksilver Fuel Pumps, which are built to deliver factory fit and consistent fuel delivery across a wide range of outboard applications. Reliable fuel delivery is the foundation of engine performance, and Quicksilver&apos;s fuel system components are engineered to handle the demanding conditions of marine use — including compatibility with current fuel formulations.</p><p>Beyond fuel systems, Quicksilver is a go-to source for Propeller Parts &amp; Accessories that help boaters maintain and optimize their propulsion systems. From hub kits that protect both prop and gearcase to installation hardware and prop tools, these components are designed to the same tolerances as the drives they support. Proper propeller maintenance is one of the most impactful things a boat owner can do for performance, efficiency, and engine longevity — and Quicksilver makes that job straightforward.</p><p>The brand&apos;s commitment extends across lubricants, impellers, thermostats, anodes, fuel filters, oil filters, maintenance kits, and complete service packages — all engineered for the marine environment and tested to meet or exceed the standards of major engine manufacturers. Whether you&apos;re performing routine seasonal maintenance or tackling a more involved repair, Quicksilver provides the parts that restore your engine to peak operating condition.</p><ul style="list-style:disc"><li>OEM-backed engineering from Mercury Marine</li><li>Compatible with Mercury, Yamaha, Honda, Evinrude, Johnson, Suzuki, and Mariner engines</li><li>Over 40,000 parts spanning 12 product lines</li><li>Formulated and tested for freshwater and saltwater environments</li><li>Trusted by DIY boaters and professional marine technicians since 1950</li></ul><p>When reliability on the water is non-negotiable, Quicksilver delivers the peace of mind that only a true OEM-backed brand can provide.</p>

Part Number

18643A 5
09/12/2036 6:25 AM
Sale Price

$364.80

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Product Details

The Quicksilver 18643A 5 is a genuine OEM triangular-shape flywheel mount engine coupler kit designed for select MerCruiser Alpha stern drive applications. Manufactured by Mercury Marine to original equipment specifications, this coupling assembly provides a precise, reliable connection between the engine and stern drive, ensuring consistent power transfer and drivetrain integrity.

This coupler is specifically designed for use with 14-inch flywheels featuring a 3-inch crankshaft bolt pattern and is compatible with engines equipped with a 1-piece rear main seal. It features the distinctive triangular flywheel mount design required by these MerCruiser applications.

Compatible Engine Applications:

  • MerCruiser 3.0L 4-cylinder engines (model years 1999–2016)
  • MerCruiser 4.5L MPI engines
  • GM-manufactured V-6 MerCruiser engines (model years 1993–2015)
  • GM-manufactured V-8 MerCruiser engines, 305 and 350 cid (model years 1993–2015)
  • All applications paired with MerCruiser Alpha stern drives

Key Features:

  • Genuine Quicksilver OEM replacement part — not aftermarket
  • Triangular shape, flywheel mount design for precision fitment
  • Engineered for 14-inch flywheels with a 3-inch crankshaft bolt pattern
  • Compatible with 1-piece rear main seal engine configurations
  • Manufactured to Mercury Marine's stringent OEM quality standards
  • Part of the trusted Mercury Marine / Quicksilver family of marine components

Quicksilver is Mercury Marine's premier brand for OEM replacement engine parts and marine accessories, backed by decades of rigorous engineering and real-world marine testing. Always consult your engine service or parts manual to confirm the correct part for your specific application before installation.

OEM / Cross-Reference Part Numbers: 18643A5, 18643A 5 | Cross-references: Sierra 18-2323, GLM 11532

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