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Sierra 18-3430 Water Pump Repair Kit for Yamaha 25-30 HP Outboard

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

18-3430
09/12/2036 11:19 AM
Sale Price

$38.47

4 left at this price

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Usually delivered within 2 days

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Product Details

The Sierra 18-3430 is a precision-engineered water pump repair kit designed for Yamaha 25 HP and 30 HP two-stroke outboard engines. This comprehensive kit provides all the essential components needed to rebuild and restore proper cooling system function in your outboard motor.

Key Features:

  • Complete rebuild kit without housing for easier servicing
  • Includes impeller, gaskets, seals, insert cup, wear plate, and hardware
  • High-quality rubber impeller for improved flexibility across broad temperature ranges
  • Designed to meet or exceed OEM specifications for reliable performance
  • All necessary components included for a complete water pump rebuild

Compatibility:

This kit fits select Yamaha 25 HP and 30 HP two-stroke outboard engines manufactured between 1987-1989 and 1992-1993. Replaces Yamaha OEM part number 6J8-W0078-A1-00 and cross-references with 6J8-W0078-A2-00, 6J8-W0078-01-00, and 6J8-W0078-00-00.

Regular water pump maintenance is critical for protecting your outboard engine from overheating damage. Sierra marine parts are manufactured to exacting standards to ensure proper fit, function, and durability in demanding marine environments. This kit makes water pump repair and maintenance straightforward, helping you maintain optimal cooling flow and engine protection throughout the boating season.

Quick and efficient

Fast and easy and prices are very good compared to others selling same item

Shipping is expensive

Great prices and fast shipping. Saved $100 buying here. Will do business again

I hope it is here Friday

So far so good...

great so far,,,easy to use site

Easy to order and a great price - look forward to receiving my parts!

Autoplicity had the best price on the item I wanted. Order process was a little odd. I didn't get any confirmation of my order being placed. So 2 days later I sent an email asking if they had received it. They answered me very quickly, sent me an order confirmation with tracking number, and it turns out my item had already shipped so I had it the next day. So ordered 5/1 and had it in my hand 5/4.

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Lowest prices on name brand items, quick shipping, and provide information on the status of your order.

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