Water Pump Impeller for Yamaha 6HP & 8HP 2-Stroke Outboards (1984–2019)
This high-performance water pump impeller is engineered for Yamaha 2-stroke outboard motors rated 6HP and 8HP, spanning model years 1984 through 2019. Designed to maintain optimal cooling system flow, this impeller ensures reliable engine temperature management in both fresh and saltwater environments.
Direct replacement for Yamaha OEM 6G1-44352-00-00 and cross-compatible with aftermarket brands including GLM Marine 89870, CEF Marine 500302, Sierra 18-3066, and Mallory 9-45610. Built with marine-grade neoprene rubber and hardened nylon for exceptional durability and chemical resistance.
- 6-blade design with precise OEM-spec dimensions for proper water flow
- Fits Yamaha 6HP (2-cylinder, 1986–2000) and 8HP (2-cylinder, 1984–2019) 2-stroke models
- Constructed from high-performance neoprene rubber and corrosion-resistant hardened nylon
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Yamaha Marine (OEM) |
6G1-44352-00-00, 6G1443520000, 6G1-44352-00, 6G14435200 |
| GLM Marine |
89870 |
| CEF Marine |
500302 |
| SEI West Sierra Marine |
18-3066 |
| Mallory Marine |
9-45610 |
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.
| Brand |
Rated HP |
Stroke |
Cylinders |
Years |
| Yamaha |
6HP |
2-Stroke |
2 |
1986–2000 |
| Yamaha |
8HP |
2-Stroke |
2 |
1984–2019 |
Technical Specifications
| Specification |
Value |
| Number of Blades |
6 |
| Impeller Height |
18.0 mm / 0.71 inch |
| Overall External Diameter |
40.0 mm / 1.57 inch |
| Hub Shaft Diameter (Internal) |
11.9 mm / 0.47 inch |
| Net Weight |
0.35 oz (10 g) |
| Materials |
Marine-grade neoprene rubber and hardened nylon |
Package Contents
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Water Pump Impeller (1 pc)
Installation Guide
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Disconnect the fuel line and remove the spark plug wire to ensure the engine cannot start during service.
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Remove the lower unit from the outboard motor following your engine's service manual. Drain any residual water or lubricant.
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Locate and remove the water pump housing cover. Note the orientation of the old impeller and any cam/key alignment.
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Extract the old impeller carefully; inspect the housing and plate for cracks, corrosion, or debris.
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Lubricate the new impeller blades with water-pump grease or glycerin to prevent dry-start damage.
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Align the impeller key or drive pin with the slot in the driveshaft, ensuring blades curve in the correct rotation direction.
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Seat the impeller fully into the housing, rotating gently if needed to help blades flex into place.
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Reinstall the water pump cover and gasket (replace the gasket if worn), torquing fasteners to spec.
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Reattach the lower unit to the motor, ensuring all shift linkages and seals are properly aligned.
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Refill the lower unit with the manufacturer-recommended gear oil and check for leaks.
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Reconnect the spark plug wire and fuel line. Run the engine in a test tank or on-water, verifying strong water flow from the tell-tale.
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Inspect for leaks or unusual noise during the first few minutes of operation; shut down immediately if cooling issues arise.
Troubleshooting & FAQ
Q: How do I confirm this impeller fits my Yamaha outboard?
A: Verify your engine is a Yamaha 6HP (1986–2000) or 8HP (1984–2019) 2-stroke, 2-cylinder model. Cross-check your existing impeller against the dimensions in the Technical Specifications table (6 blades, 40mm OD, 11.9mm shaft) and confirm your OEM part number matches 6G1-44352-00-00 or equivalents listed.
Q: How often should I replace my water pump impeller?
A: Replace the impeller every 2–3 years or 200–300 operating hours, whichever comes first. Inspect it annually for cracks, missing blade tips, or brittleness—especially if the engine has been run dry or stored for extended periods.
Q: What are the signs my impeller is failing?
A: Watch for weak or no water flow from the tell-tale, engine overheating, steam from the powerhead, or a high-temperature alarm. If you notice any of these symptoms, shut down immediately and inspect the impeller and cooling passages.
Q: Can I install this impeller myself, or do I need a mechanic?
A: DIY installation is feasible if you have basic mechanical skills and tools; follow your engine's service manual for torque specs and alignment. Professional installation is recommended if you're unfamiliar with lower-unit disassembly or if shift linkages are complex.
Q: Will this aftermarket impeller perform the same as the OEM Yamaha part?
A: Yes—this impeller is manufactured to OEM specifications using marine-grade neoprene rubber and hardened nylon in an ISO9002-certified facility. Each batch undergoes quality inspection to ensure fitment and performance match or exceed original-equipment standards.
Q: Is this an OEM or aftermarket part?
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?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.