Water Pump Repair Kit – Fits Yamaha F300/F350 Outboard Motors (Replaces 6AW-W0078-00)

Water Pump Repair Kit – Fits Yamaha F300/F350 Outboard Motors (Replaces 6AW-W0078-00)

This water pump repair kit provides all necessary components to restore the cooling system on Yamaha 4-Stroke V8 outboard motors. It is designed for F300, F350, LF300, and LF350 models manufactured between 2007 and 2011.

This kit is a direct replacement for Yamaha part numbers 6AW-W0078-00 and 6AW-W0078-00-00, as well as Sierra aftermarket part number 18-3477.

• Installation Type: OEM factory direct replacement.
• Core Components: Includes the impeller, gaskets, cartridge insert, outer plate, o-rings, and hardware.
• Housing Requirement: Designed for use with water pump housing 6AW-44311-01-00, which is sold separately.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below. For Yamaha owners, here’s a guide to help you identify your engine’s serial/model: Yamaha Serial Number Guide. You can also review exploded diagrams to verify part numbers: Yamaha Parts Diagrams & Catalog.

Technical Specifications

Package Contents

• 1 x Gasket, Water Pump (6AW-44315-00-00)
• 1 x Insert, Cartridge (6AW-44322-00-00)
• 1 x Outer Plate, Cartridge (6AW-44323-00-00)
• 1 x Key (6AW-44336-00-00)
• 1 x Impeller (6AW-44352-00-00)
• 4 x Bolt, With Washer (90119-08M14-00)
• 1 x O-Ring (93210-37M67-00)
• 1 x O-Ring (93210-94003-00)
• 2 x Pin, Dowel (93606-12019-00)

Note: This kit repairs the water pump but does not include the pump housing (part # 6AW-44311-01-00), which must be purchased separately if needed.

Installation Guide

1. Safety First: Disconnect the battery and ensure the engine is securely positioned before starting.
2. Remove Lower Unit: Drain the gearcase oil, then unbolt and carefully remove the lower unit (gearcase) from the outboard motor.
3. Access the Pump: Locate and unbolt the water pump housing, which sits on top of the gearcase.
4. Disassemble: Remove the old housing, impeller, wear plate, gaskets, and O-rings. Note the orientation of the impeller vanes.
5. Clean Surfaces: Thoroughly clean all mating surfaces, removing any old gasket material or corrosion.
6. Install New Components: Place the new gasket and cartridge plate. Insert the new impeller into the housing, rotating it in the correct direction to bend the vanes properly.
7. Reassemble Pump: Install the new O-rings and dowel pins. Securely bolt the housing back onto the gearcase, tightening bolts to the manufacturer's torque specifications.
8. Reinstall Lower Unit: Guide the lower unit back into place, ensuring the driveshaft and water tube align correctly. Bolt it securely.
9. Final Checks: Refill the gearcase with fresh oil. Reconnect the battery and start the engine on a water supply to verify a strong, steady stream from the tell-tale outlet.

Troubleshooting & FAQ

Q: How do I confirm this kit fits my specific engine? A: Please use the "Compatible Engine Models" table above. Cross-reference your outboard's model, horsepower, and year to ensure it is listed. Verifying the OEM part number (6AW-W0078-00) against your engine's service manual is the most reliable method.

Q: Do I need to buy the water pump housing separately? A: Yes. This kit includes all the internal components like the impeller, gaskets, and plates, but it is designed for use with the existing water pump housing (6AW-44311-01-00). If your housing is cracked, warped, or heavily corroded, you must purchase it separately.

Q: What are the signs of a failing water pump? A: Common symptoms include the engine overheating at idle or low speeds, an alarm sounding, or a weak or non-existent water stream from the "tell-tale" outlet. Reduced engine performance can also be a sign of poor cooling.

Q: How often should I replace the water pump impeller and kit? A: For preventative maintenance, it is recommended to replace the water pump impeller and related seals every 1 to 2 years, or every 100-200 hours of operation, depending on usage conditions (e.g., saltwater vs. freshwater).

Q: OEM vs. Aftermarket? A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost? A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy? A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.