Sierra 18-3440 3440 Yamaha Water Pump Repair Kit

SKU: 4002192 - UPC: 808282185718 - MPN: 18-3440
$56.69 $70.79 ( / )

Available Stock : 5

Revitalize Your Yamaha Outboard with the Sierra 18-3440 Repair Kit Keeping your Yamaha outboard motor's cooling system in top shape is crucial for reliable performance on the water. The Sierra 18-3440 water pump repair kit steps in as a dependable solution for restoring optimal water flow and preventing overheating issues...
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Sierra 18-3440 3440 Yamaha Water Pump Repair Kit Product Description

Revitalize Your Yamaha Outboard with the Sierra 18-3440 Repair Kit

Keeping your Yamaha outboard motor's cooling system in top shape is crucial for reliable performance on the water. The Sierra 18-3440 water pump repair kit steps in as a dependable solution for restoring optimal water flow and preventing overheating issues that plague many boaters. Designed specifically for select Yamaha models, this kit tackles wear from constant exposure to saltwater, debris, and high RPMs—common culprits behind impeller failure and reduced pump efficiency.

Boaters often notice early warning signs like steam from the engine cowling, erratic temperature gauges, or milky oil from coolant leaks. Addressing these promptly with a quality rebuild kit can extend your engine's life and save you from costly full pump replacements.

Perfect Fit for Yamaha Outboards

This kit aligns seamlessly with various Yamaha 2-stroke and 4-stroke outboards in the 40-90 HP range, including popular models from the 1980s through early 2000s. It's engineered to match OEM specifications, ensuring no modifications are needed for a straightforward swap. Always cross-check your engine's serial number against compatibility charts for the best results—precision fitment minimizes downtime during your boating season prep.

  • Supports multiple Yamaha engine families for broad application.
  • Ideal for freshwater and saltwater environments.
  • Restores factory-level water pressure to safeguard against engine damage.

Kit Contents: Everything You Need for a Complete Rebuild

The Sierra 18-3440 delivers a full suite of high-grade components, eliminating the hassle of sourcing parts individually. Inside, you'll find:

  • Durable neoprene impeller for superior flexibility and longevity.
  • Precision-machined wear plate to combat erosion.
  • Gaskets, seals, and O-rings for leak-proof assembly.
  • Key and liner for secure, balanced operation.

These elements are crafted from corrosion-resistant materials, standing up to the harsh marine conditions that degrade lesser kits quickly.

Key Benefits for Boaters and Mechanics

Upgrading to this repair kit isn't just about fixing—it's about enhancing reliability and performance. Expect improved cooling efficiency, quieter operation, and peace of mind knowing your engine won't leave you stranded mid-trip. Sierra's rigorous testing ensures each component exceeds industry standards for tensile strength and heat resistance.

Close-up of Sierra water pump impeller in action, showing flexible neoprene blades pumping water efficiently.
Flexible impeller design ensures consistent water flow even under heavy load.

DIY enthusiasts appreciate the cost savings over dealer services, while pros value the consistent quality that speeds up jobs. Regular rebuilds every 1-2 years (or 200 hours) can prevent 90% of overheating failures, based on common marine maintenance data.

Step-by-Step Installation Guide

Rebuilding your water pump takes about 1-2 hours with basic tools. Here's a proven approach:

  1. Drain the cooling system and remove the lower unit.
  2. Disassemble the pump housing, inspecting for cracks or scoring.
  3. Remove the old impeller using needle-nose pliers—twist counterclockwise.
  4. Clean all surfaces thoroughly; replace the wear plate if grooved.
  5. Lubricate new parts with marine grease, then install in reverse order.
  6. Prime the pump by filling with water before reassembly.
  7. Test-run the engine on muffs, monitoring for steady water telltale flow.

Pro Tip: Winterize by removing the impeller to prevent flat-spotting from dry storage. Use anti-seize on stainless screws to fight corrosion.

Maintenance Tips to Maximize Longevity

Preventive care amplifies the kit's value. Flush after every saltwater outing, inspect annually for impeller glazing, and avoid dry-running the pump. Pair with a proper zinc anode setup to shield against electrolysis. These habits can double the service interval, keeping your Yamaha humming season after season.

Common pitfalls? Skipping the primer lube or reusing old gaskets—both lead to leaks. Stay vigilant, and your investment pays off in uninterrupted adventures.

Why Sierra Stands Out in Marine Aftermarket

Sierra's reputation is built on over 40 years of innovation, supplying parts to major OEMs and earning trust from millions of boaters. Their kits undergo stringent QA, including burst testing and flow simulations, outperforming generics in real-world durability trials. Choose Sierra for parts that feel—and perform—like the originals, without the premium markup.

Frequently Asked Questions

Is the Sierra 18-3440 compatible with my Yamaha 50HP outboard?

Yes, it fits many Yamaha 40-90HP models from various years. Verify your engine's model and serial for exact match.

How often should I replace the water pump impeller?

Every 1-2 years or 200 hours of use, especially in saltwater, to avoid overheating risks.

Can I install this kit myself without special tools?

Absolutely—basic pliers, screwdrivers, and grease suffice. Follow a step-by-step guide for best results.

What's included in the Sierra 18-3440 kit?

Impeller, wear plate, gaskets, seals, O-rings, key, and liner for a complete rebuild.

Will this kit improve cooling performance?

Yes, it restores full water flow, reducing engine temps and enhancing overall efficiency.

Is Sierra equivalent to OEM Yamaha parts?

Sierra matches or exceeds OEM specs in materials and testing, at a fraction of the cost.

How do I know if my water pump needs repair?

Look for weak telltale stream, overheating, or impeller chunks in the strainer.

Refer to Sierra's Catalog for more information



Save $14 when you buy the Sierra 18-3440 3440 Yamaha Water Pump Repair Kit for only $56 from NVN Marine! Same day shipping before 3pm.

Sierra 18-3440 3440 Yamaha Water Pump Repair Kit Technical Specifications

Type: 

Engine | Parts / Drive

Vendor: 

Sierra Engine Parts

Weight: 

0.5 lb

Description: 

Repair Kit w/o Housing

OEM #: 

66T-W0078-00-00

Sierra 18-3440 3440 Yamaha Water Pump Repair Kit User Reviews

Sierra 18-3440 3440 Yamaha Water Pump Repair Kit Shipping & Return

Shipping Weight: 

0.5 lb

Box Sizes: 

2.00 (h) x 4.00 (w) x 4.00 (l)

Cubic Feet: 

32.0

Returnable: 

Yes

For detailed shipping policy please check our Shipping Policy and you can find our Return and Refund Policy here.

Sierra 18-3440 3440 Yamaha Water Pump Repair Kit

$56.69 $70.79 ( / )