Sierra Impeller 18-3086 (AP-007) – Yamaha Outboard Water Pump Replacement
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
The Sierra 18-3086 Impeller (AP-007) is a direct replacement raw water pump impeller designed for Yamaha outboards. This impeller is responsible for circulating cooling water through the engine, ensuring proper temperature regulation and preventing overheating.
Manufactured to meet or exceed OEM specifications, this impeller features durable, flexible rubber vanes and a precision-fit hub for reliable performance in both freshwater and saltwater environments.
Ideal for routine maintenance, this impeller restores cooling system efficiency and helps protect your engine from heat-related damage.
Key Features
- Direct replacement raw water pump impeller
- Flexible rubber vanes for efficient water flow
- Precision-fit hub for secure installation
- Maintains proper engine cooling performance
- Marine-grade construction for long service life
- Sierra limited lifetime warranty
Engine Compatibility
Yamaha Outboards (2-Stroke)
- 9.9 HP
- 15 HP
Yamaha Outboards (4-Stroke)
- F8
- F9.9
- F15
Tohatsu / Nissan (Yamaha-built models)
- Equivalent small horsepower outboards
➡️ Commonly used in portable and small outboard engines
Serial Number Fitment Notice
Fitment depends on:
- Model year
- Water pump housing type
- Shaft spline configuration
⚠️ Always confirm using:
- Engine serial number
- OEM part number match
When This Part Needs Replacement
Replace the impeller if you notice:
- Weak or no telltale stream
- Engine overheating
- Reduced cooling performance
- Cracked, hardened, or missing vanes
- After seasonal storage
Recommended service interval: every 100 hours or annually
Installation Notes
- Lubricate impeller before installation
- Install vanes in correct rotation direction
- Inspect housing and wear plate
- Ensure proper key alignment on shaft
- Replace gaskets or seals as needed
Alternate / Superseded Part Numbers
OEM Cross References
- Yamaha: 6G1-44352-00-00
- Yamaha: 6G1-44352-01-00
Aftermarket Cross References
- Sierra: 18-3086
- Mallory: 9-45602
- GLM: 12020
Shipping
Shipping: Ships same or next day for fast Canada wide shipping. ⚓
💡 Parts Desk Insight
Small outboard impellers are easy to overlook, but they’re one of the most important maintenance items. Even light use or sitting unused can cause the rubber to stiffen and reduce water flow.
Replacing it regularly keeps your engine running cool and reliable every time you head out 👍
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.