Water Pump Impeller Kit for Yamaha 150/175/200/225HP 6G5-W0078-00

Water Pump Repair Kit – Fits Yamaha 150-225HP V6 Outboards (Replaces 6G5-W0078-A1-00)

This water pump repair kit is designed for Yamaha 2-Stroke V6 outboard motors, including 150HP, 175HP, 200HP, and 225HP models manufactured between 1984 and 1991. It provides all the necessary components for a complete and reliable water pump service to maintain optimal engine cooling.

This kit is a direct replacement for Yamaha OEM part numbers 6G5-W0078-A1-00, 6G5-W0078-00-00, and 6G5-W0078-01-00. It also cross-references with Sierra 18-3310 and Mallory 9-48618.

• Includes a new aluminum housing, impeller, gaskets, and installation hardware.
• Engineered for direct replacement to ensure proper fit and function.
• Specifically designed for Yamaha 2-Stroke V6 outboard engines.

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 Housing (6E5-44311-00-00)
• 1 x Impeller (6E5-44352-01-00)
• 1 x Gasket, Water Pump (6E5-44315-A0-00)
• 1 x Insert, Cartridge (61A-44322-00-00/6E5-44322-00-00)
• 1 x Outer Plate, Cartridge (6G5-44323-00-00/6G5-44323-01-00)
• 1 x Key, Woodruff (90280-04M05-00)
• 1 x O-Ring (93210-37M67-00)
• 1 x O-Ring (93210-86M38-00)
• 2 x Pin, Dowel (93606-12019-00)
• 4 x Bolt (97080-08045-00/97095-08045-00)
• 4 x Washer (90209-08M02-00)

Installation Guide

1. Disconnect the negative battery cable to prevent accidental starting.
2. Place the outboard in forward gear and remove the bolts securing the lower unit (gearcase). Carefully separate it from the upper housing.
3. Unscrew the bolts on the water pump housing and lift the housing off the driveshaft.
4. Remove the old impeller, Woodruff key, wear plate, and gaskets. Take note of their orientation.
5. Thoroughly clean the mating surfaces on the gearcase and the inside of the housing.
6. Install the new gasket and wear plate onto the gearcase.
7. Slide the new Woodruff key into the driveshaft slot and install the new impeller, turning the driveshaft clockwise to seat the vanes.
8. Apply a light coat of marine grease to the inside of the new housing and install it over the impeller.
9. Fasten the housing with the new bolts and washers, tightening them to the torque specified in your service manual.
10. Reinstall the lower unit, ensuring the driveshaft, shift shaft, and water tube are correctly aligned.
11. Reconnect the battery cable.
12. Test the engine using a water supply (flushing muffs or in water) and check for a strong, steady stream from the tell-tale outlet.

Troubleshooting & FAQ

How do I confirm this kit fits my engine?
Verify your engine's model, horsepower (HP), and year by checking the ID plate on the transom bracket. Cross-reference this information with our compatibility table. It is also best practice to compare the OEM part number (6G5-W0078-A1-00) with your service manual or existing part.

What are the signs of a failing water pump?
Common symptoms include the engine overheating alarm sounding, a weak or nonexistent water stream from the "tell-tale" port, or steam coming from the exhaust. Reduced engine performance can also indicate a cooling problem.

How often should I replace the water pump kit?
For preventative maintenance, it is recommended to replace the water pump impeller every 1 to 2 years or every 100-200 hours of operation. If you operate in sandy or silty water, more frequent inspections and replacements are advised.

Does this kit include the pump housing?
Yes, this is a complete repair kit that includes the aluminum water pump housing, along with the impeller, gaskets, plates, O-rings, and all necessary bolts and hardware for a full replacement.

OEM vs. Aftermarket?
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.

How fast do you ship and how much does it cost?
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.

What is your warranty and return policy?
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.