Welcome Aboard!

10% savings across all ranges sitewide for new customers · Terms apply

FLASHSALE26

Water Pump Repair Kit for Yamaha F225, F250 and F300 4.2L V6 Outboards – Cross-References 6CE-W0078-01-00 and 6CE-W0078-02-00

Regular price $29.99

Worry-free returns

Shop with confidence. If you’re not completely satisfied, eligible items may be returned within the return window, provided they are unused and in original packaging.


If the return is due to our error or a defective item, we’ll make it right.


Please contact us before returning any item.

Delivery and Shipping

Orders are typically processed within 1–2 business days.


U.S. orders usually arrive within 6–15 days, depending on stock location and destination.


International delivery times may vary due to customs processing.


Tracking information will be provided once your order ships.

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

Product Details

This aftermarket Water Pump Repair Kit is designed for selected Yamaha 4-stroke 4.2L V6 outboards in the F225, F250 and F300 families. It services the lower-unit water pump assembly and helps restore dependable cooling-water circulation when the impeller and related wear components require replacement.

The product is associated with Yamaha water pump repair-kit references 6CE-W0078-01-00 and 6CE-W0078-02-00. These references appear across different Yamaha model years and catalog revisions, so always match the exact model, year and serial-number range before ordering.

  • Product type: Aftermarket water pump repair kit
  • Application: Lower-unit water pump assembly
  • Installation: Replacement service part; professional installation is recommended
  • Brand status: Aftermarket replacement, not a Yamaha-branded OEM component

Part Number References

Use these references as cross-checking aids only. Part-number appearance in a catalog does not replace confirmation of the complete engine model and year.

Brand Reference Use
Yamaha 6CE-W0078-01-00 Water pump repair-kit reference used on selected earlier 4.2L V6 applications
Yamaha 6CE-W0078-02-00 Water pump repair-kit reference used on selected later applications
Sierra 18-3470 Aftermarket water pump repair-kit reference
Sierra 18-3471 Aftermarket water pump repair-kit reference

Engine Compatibility

The following Yamaha 4-stroke models are represented in the available catalog cross-references. Confirm the exact model designation, year and serial-number range against the engine identification label and service documentation before purchase.

Models Rated HP Stroke Catalog years shown
F225F, F225B, F225NCA, F225XB, F225XCA, LF225XB, LF225XCA 225 4-Stroke 2009 and later applications; specific model-year coverage varies
F250D, F250NCA, F250UCA, F250XB, F250XCA, LF250UCA, LF250XB, LF250XCA, VF250XA 250 4-Stroke 2011 and later applications; some listed configurations are 2014–2016 or 2015–2016
F300B, F300BETU, F300BETX, F300NCA, F300UCA, F300XCA, F300C, FL300BETU, FL300BETX, LF300UCA, LF300XCA 300 4-Stroke 2011 and later applications; specific model-year coverage varies

Important: Do not assume that every Yamaha 4.2L V6 outboard uses the same water-pump service parts. Differences may exist by model, year, lower-unit configuration and serial-number range.

Technical Specifications

Product Type
Water pump repair kit
Application
Yamaha 4-stroke 4.2L V6 outboards, selected F225/F250/F300 applications
Installation Location
Lower-unit water pump assembly
Replacement Type
Aftermarket service replacement
OEM References
6CE-W0078-01-00 and 6CE-W0078-02-00

What's Included

The listed service components are intended for servicing the water-pump assembly. Component appearance and exact contents may vary by production batch, so compare the supplied parts with the original assembly before installation.

  • 1 × Water pump impeller, reference 6CE-44352-00-00
  • 1 × Impeller key, reference 90280-04M05-00
  • 1 × O-ring, reference 93210-94003-00
  • 4 × Bolts, reference 97095-08045-00
  • 2 × Oil seals, reference 93104-22M07-00
  • 1 × Cartridge insert, reference 6AW-44322-00-00

This listing does not represent a complete lower-unit replacement and does not include the engine, gearcase or any component not listed above. The existing water-pump housing must be serviceable unless a separate housing is specifically supplied.

Installation Notes

  1. Disconnect the battery and secure the outboard according to the manufacturer's service procedure.
  2. Place a suitable drain pan beneath the lower unit. If the lower unit is removed, follow the manufacturer's procedure for draining and refilling gear lubricant.
  3. Remove the lower-unit mounting hardware and carefully separate the gearcase from the upper casing.
  4. Remove the water-pump cover or housing and note the orientation of the impeller, key, seals and other components.
  5. Clean the mating surfaces and inspect the pump housing, wear surfaces, driveshaft and water-tube connection. Replace damaged components before reassembly.
  6. Install the new impeller with the key correctly seated and assemble the supplied service parts in the same orientation as the original components.
  7. Use a suitable marine lubricant where specified by the service manual. Do not lubricate components where the manufacturer prohibits it.
  8. Reinstall the water-pump housing and tighten fasteners to the manufacturer's specified torque.
  9. Reinstall and secure the lower unit, then refill the gearcase with the correct marine gear lubricant if it was drained.
  10. Run the engine only with an appropriate water supply and verify a strong, consistent tell-tale stream and normal operating temperature.

Always use the service manual for the exact engine model and follow all torque, sealing and lubrication specifications. Improper water-pump installation can cause overheating and severe engine damage.

Troubleshooting & FAQ

What are common signs of a worn water-pump impeller?

Possible signs include overheating, reduced or intermittent tell-tale flow, an alarm at idle or low speed, or an impeller that is cracked, brittle, deformed or missing vanes during inspection.

Does this kit include the complete water-pump housing?

No. This listing is for the service components listed in the box contents. The existing housing and related lower-unit components must be inspected and reused if they are undamaged, or replaced separately if worn.

Does this fit every Yamaha 4.2L V6 outboard?

No. The compatibility information covers selected F225, F250 and F300 4-stroke applications. Confirm the exact model, year and serial-number range before ordering.

Is this an OEM Yamaha part?

No. This is an aftermarket replacement kit intended to cross-reference the listed Yamaha and Sierra service-part references. It is not manufactured or branded by Yamaha.

How often should the impeller be replaced?

Replacement intervals depend on the manufacturer's service schedule, operating hours and conditions such as saltwater use, sand or silt exposure and periods of storage. Inspect the impeller regularly and replace it when the service manual specifies or whenever wear is found.

What should I verify before ordering?

Compare the engine model designation, horsepower, stroke, year, serial-number range, original part number and the existing pump components. If any of these details do not match, consult a qualified marine technician before purchasing.

Safety & Important Information

  • Disconnect the battery before servicing the lower unit.
  • Never run an outboard without an adequate water supply.
  • Use the correct torque values, lubricants and sealants from the applicable service manual.
  • Inspect the pump housing and related wear surfaces before installing new components.
  • Professional installation is recommended, especially when lower-unit removal or gearcase service is required.

About Sea Sierra

  • Marine replacement parts — Practical aftermarket service components for routine maintenance and repair.
  • Application-focused listings — Compatibility references are provided to help customers compare model and part-number information.
  • Service support — Verify the exact engine configuration before installation for safe and reliable operation.

Payment & Security

Payment methods

  • American Express
  • Apple Pay
  • Cartes Bancaires
  • Diners Club
  • Discover
  • Google Pay
  • JCB
  • Maestro
  • Mastercard
  • PayPal
  • Union Pay
  • Visa

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.