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Water Pump Repair Kit – Fits Yamaha 6HP, 8HP & 9.9HP 4-Stroke Outboards (Replaces 68T-W0078-00-00)

Regular price $56.99
Shipping calculated at checkout.

Worry-free returns

You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This Water Pump Repair Kit is designed for a precise fit on a range of Yamaha 4-stroke outboards, including 6HP (F6A, F6B), 8HP (F8C, F8F), and 9.9HP (F9.9F, F9.9J) models manufactured from 2001 through 2020. It provides all essential components to restore the engine's cooling system for optimal performance and reliability.

This kit serves as a direct replacement for Yamaha part numbers 68T-W0078-00-00 and 68T-W0078-01-00, as well as Sierra aftermarket part 18-3450.

  • Installs as a direct replacement without modifications.
  • Includes the impeller, housing insert, plate, and all necessary seals and bolts.
  • Built with durable steel and plastic components to match OEM specifications.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand Part Number Superseded By Notes
Yamaha 68T-W0078-00-00 68T-W0078-01-00 Original OEM Number
Yamaha 68T-W0078-01-00 Current OEM Number
Sierra 18-3450 Aftermarket Interchange

Engine & Model Compatibility

Confirm your engine model/year in the table below.

Brand Model Rated HP Stroke Years OEM Part No. Notes
Yamaha F6AM 6 4-Stroke 2007–2008 68T-W0078-00-00
Yamaha F6MLH/F6MSH 6 4-Stroke 2001–2006 68T-W0078-00-00
Yamaha F8MLH/F8MSH 8 4-Stroke 2001–2006 68T-W0078-00-00
Yamaha F8CM/F9.9FE/F9.9FM 8-9.9 4-Stroke 2007–2010 68T-W0078-00-00
Yamaha F8LMH/F8SMH 8 4-Stroke 2011–2020 68T-W0078-00-00
Yamaha F9.9LE/F9.9LMH/F9.9SMH 9.9 4-Stroke 2011–2020 68T-W0078-00-00
Yamaha F9.9LEHB/F9.9SEHB 9.9 4-Stroke 2013–2014 68T-W0078-00-00

Technical Specs

Product Type
Water Pump Repair Kit
Installation
Direct replacement
Housing Material
Steel/Plastic Components
Product Dimensions
15.5" L x 10.0" W x 5.0" H

What’s in the Box

  • 1 x Cartridge Insert (63V-44322-00-00)
  • 1 x Water Seal Damper (68T-44366-00-00)
  • 1 x Impeller (68T-44352-00-00)
  • 1 x Woodruff Key (664-44338-00-00)
  • 1 x O-Ring (93210-44704-00)
  • 1 x Cartridge Outer Plate (68T-44323-00-00)
  • 4 x Bolts (97095-08045-00)

Installation Notes

  1. Disconnect the spark plug leads and battery cables for safety.
  2. Drain the gearcase lubricant into a suitable container.
  3. Remove the mounting bolts securing the lower unit (gearcase) to the engine's midsection and carefully lower it.
  4. Unscrew the bolts from the water pump housing to access the old components.
  5. Remove the old impeller, gaskets, wear plate, and seals. Note their orientation.
  6. Thoroughly clean the mating surfaces, removing any old gasket material or corrosion.
  7. Install the new components from the kit in the reverse order of removal. Lightly grease the new impeller.
  8. Torque the water pump housing and lower unit bolts to the manufacturer's specified values.
  9. Refill the gearcase with the recommended marine lubricant before starting the engine.
  10. Once reassembled, test the engine in a water source to confirm proper water flow from the tell-tale port.

Troubleshooting & FAQ

How do I know if this kit fits my engine?

This kit is for specific Yamaha 6HP, 8HP, and 9.9HP 4-stroke models from 2001-2020. Please verify your exact engine model and year against the compatibility table provided on this page. Cross-referencing your old part number with the numbers in our Part Number Matrix is also a reliable method.

What are the signs of a failing water pump?

Common symptoms include a weak or non-existent water stream from the "tell-tale" outlet, engine overheating alarms, and reduced engine performance. A visual inspection of the old impeller may show cracked, brittle, or broken vanes.

How often should the water pump impeller be replaced?

As a general maintenance guideline, it is recommended to inspect the impeller annually and replace it every 1-2 years or every 100-200 hours of operation, depending on usage conditions (e.g., saltwater vs. freshwater).

Is the water pump housing included in this repair kit?

This kit is a standard repair kit and does not include the main upper or lower water pump housing. It includes the cartridge insert, outer plate, impeller, and related seals and hardware needed for a typical service.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

  • Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
  • This is an aftermarket replacement, not an OEM component.
  • Professional installation is recommended for safety and performance.

About Sea Sierra

  • Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
  • Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
  • Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

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