Sierra Marine Water Pump Kit 18-3205 – Yamaha 9.9-15HP 2-Stroke Cooling System Rebuild
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
The Sierra 18-3205 Water Pump Kit is a complete cooling system rebuild solution for Yamaha small horsepower 2-stroke outboards. Designed to restore proper water flow and engine cooling, this kit replaces all critical wear components inside the water pump assembly.
This is a “without housing” kit, meaning it includes the impeller, wear plate, cup, seals, and gaskets while reusing the existing housing. Ideal for routine maintenance or correcting weak telltale flow and overheating issues.
Manufactured to meet or exceed OEM specifications, this kit ensures reliable cooling performance and long service life in both freshwater and saltwater environments.
Key Features
- Complete internal water pump rebuild kit (no housing)
- Includes impeller, cup, wear plate, gaskets, seals, and key
- Restores proper cooling water circulation
- Direct OEM replacement fit and performance
- Designed for Yamaha small HP 2-stroke platforms
- Sierra lifetime warranty
Engine Compatibility
Yamaha Outboards (2-Stroke)
- 9.9 HP
- 15 HP
➡️ Fits most 2-cylinder Yamaha 2-stroke engines using standard lower units.
Mariner (Yamaha-built models)
- 9.9 HP
- 15 HP
These engines share the same Yamaha powerhead and lower unit design, making this kit cross-compatible.
Serial Number Fitment Notice
Fitment varies by shaft length and production year.
⚠️ Always confirm using your engine serial number before ordering, especially on:
- Early vs late model transitions
- Yamaha vs Yamaha-built Mariner models
When This Part Needs Replacement
Replace the water pump kit if you notice:
- Weak or no telltale stream
- Engine overheating
- Reduced cooling at idle
- Impeller cracking, swelling, or hardening
- Engine stored dry for long periods
Recommended service interval: every 100 hours or annually
Installation Notes
- This kit does NOT include the housing
- Inspect housing and replace if worn or scored
- Install impeller with correct vane direction
- Use marine grease during installation
- Replace key and seals to prevent failure
- Ensure proper gasket sealing
Alternate / Superseded Part Numbers
OEM Cross References
- Yamaha:
- 682-W0078-00-00
- 682-W0078-A0-00
Aftermarket Cross References
- Mallory: 9-45605
- GLM: 12025
Shipping
Shipping: Ships same or next day for fast Canada wide shipping. ⚓
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.