688-44352 Water Pump Impeller & Key for Yamaha | JLM Marine

Water Pump Impeller & Key – Fits Yamaha 2-Stroke 60–90 HP Outboard Motors

This aftermarket water pump impeller kit is engineered for Yamaha 2-stroke outboard motors rated 60–90 HP, including C75, P75, C80, C85, CV85, B90, C90, and E75 models from 1984 through 2004 and beyond. Designed to restore efficient cooling system performance, this impeller assembly ensures reliable water flow to prevent engine overheating.

Direct Replacements: Yamaha 688-44352-03-00, 688443520300, 688-44352-03, 6884435203, 688 44352 03 | CEF 500323 | Sierra 18-3070 | Mallory 9-45603

• Package includes impeller and drive key/pin for complete installation
• 6-blade rubber impeller designed for optimal water circulation
• Precision-molded to OEM specifications for reliable fitment

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

• Outboard Rubber Impeller (6-blade)
• Drive Key / Pin

Installation Guide

1. Disconnect the fuel line and remove the lower unit from the outboard motor following your service manual. Ensure the engine is cool and the ignition is off.
2. Remove the water pump housing cover by unscrewing the fastening bolts. Keep all hardware organized for reassembly.
3. Extract the old impeller carefully using pliers if necessary. Inspect the housing and plate for wear, corrosion, or debris.
4. Clean the pump chamber thoroughly with a soft cloth. Remove any residual gasket material or buildup.
5. Lubricate the new impeller blades with glycerin, waterproof grease, or soapy water—never use petroleum-based lubricants. Coat the inside of the pump housing as well.
6. Insert the drive key/pin into the impeller shaft slot, ensuring it is fully seated and properly aligned.
7. Install the new impeller by rotating it in the correct direction (usually counterclockwise) while gently pressing it into the housing. Ensure all blades fold smoothly without kinking.
8. Position the pump plate and gasket over the impeller, aligning all bolt holes. Use a new gasket if the old one is damaged.
9. Reinstall the housing cover and tighten bolts in a crisscross pattern to the torque specified in your service manual.
10. Reattach the lower unit to the motor, ensuring proper alignment of the driveshaft and water tube.
11. Reconnect the fuel line and run the engine in a test tank or on muffs. Verify strong water flow from the telltale (pilot) hole.
12. Inspect for leaks around the pump housing. If any are detected, shut down immediately and recheck gasket seating and bolt torque.

Troubleshooting & FAQ

How do I confirm this impeller fits my Yamaha outboard?
Check the Compatible Engine Models table above for your motor's HP, stroke, and year range. Cross-reference your original Yamaha part number (688-44352-03-00 or equivalent) with the Part Number Cross-Reference table, or consult your engine's service manual and parts diagram.

How often should I replace my water pump impeller?
Most manufacturers recommend annual replacement or every 200–300 operating hours, whichever comes first. If you frequently run in sandy, silty, or debris-laden water, inspect and replace more often to prevent cooling system failure.

What are the signs of a failing impeller?
Common symptoms include weak or absent water flow from the telltale hole, engine overheating alarms, steam from the powerhead, or a drop in performance. Cracked, missing, or melted impeller blades during inspection indicate immediate replacement is needed.

Can I reuse the drive key, or must I replace it?
Always inspect the key for wear, corrosion, or deformation. While it may appear intact, replacing it with the new key included in this kit ensures reliable drive engagement and prevents future slippage or damage.

Why did my new impeller fail prematurely?
Common causes include running the engine dry (even briefly), improper lubrication during installation, debris in the pump housing, a misaligned water tube, or using petroleum-based greases that degrade rubber. Always prime the system and use compatible lubricants.

Is this an OEM part or 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.