Westerbeke Impeller Kit 48500 – Raw Water Pump Service Kit
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The Westerbeke Impeller Kit 48500 is a complete raw water pump service kit designed for Westerbeke marine diesel engines and generators. This kit includes a precision-molded neoprene impeller along with sealing components and hardware to restore proper cooling system performance and ensure reliable operation.
The impeller is responsible for drawing seawater through the cooling system. Over time, the flexible vanes can wear, harden, or break, reducing water flow and increasing the risk of overheating. Replacing the impeller at recommended intervals helps maintain consistent cooling and protects your engine or generator from damage.
This kit is widely used across Westerbeke generator and engine platforms, making it a key maintenance item for dependable marine operation.
Key Features
- Complete raw water pump impeller service kit
- Marine-grade neoprene impeller construction
- 6-blade flexible impeller design
- Includes O-ring, gasket, and mounting hardware
- Maintains proper raw water flow and cooling performance
- OEM-equivalent fit and function
Engine Compatibility
Westerbeke Marine Diesel Generators
- 5.7 BTD
- 6.0 BTDA
- 7.5 BTD / BTDA
- 7.6 BTD
- 8.0 BTDA
- 8.3 BTD
- 9.4 BTDA / BTDB
- 10.0 BTD / BTDA
- 11.0 BTD
- 12.0 BTDC
- 12.5 BTDA / BTDB
- 15.0 BTDC
Westerbeke Marine Diesel Engines
- 12C Two
- 20B Two
- 30B Three
- 35C / 35D / 35E Three
- 38B Four
- 42B Four
- 44A / 44B / 44C Four
➡️ Fits engines using compatible Westerbeke raw water pumps
Serial Number Fitment Notice
Fitment depends on:
- Pump model
- Engine model and year
- Pump cover design
⚠️ Important Fitment Note:
- Fits pumps 48080 / 048080 and 37431 / 037431
- Designed for new-style round 6-bolt cover pumps (2004+)
- Will NOT fit older pump model 33636 (scalloped cover)
Always confirm compatibility using your pump model or engine serial number before ordering.
Impeller Specifications
- Diameter: ~2.0" (50.8 mm)
- Width: ~22 mm
- Shaft: Slotted / pin drive
- Blade Count: 6
- Material: Neoprene rubber
What’s Included in the Kit
- Impeller
- O-ring
- Gaskets
- Mounting screw / hardware
When This Part Needs Replacement
Replace the impeller if you notice:
- Reduced or no cooling water flow
- Generator or engine overheating
- Cracked, missing, or stiff vanes
- Reduced output under load
Recommended service interval: every 100–200 hours or annually
Installation Notes
- Lubricate impeller before installation
- Install with correct vane direction
- Replace all gaskets and O-rings
- Inspect pump housing and wear surfaces
- Verify pump style (round vs scalloped cover) before install
Alternate / Superseded Part Numbers
OEM Cross References
- Westerbeke: 48500, 048500
Aftermarket Cross References
- StayCoolPumps: SCP-48500
- Various aftermarket equivalents (QuickMarine, SOXA, etc.)
Shipping
Shipping: Ships same or next day for fast Canada wide shipping. ⚓
💡 Parts Desk Insight
This is a very common Westerbeke generator impeller—but the pump cover style matters. The newer round 6-bolt pumps and older scalloped pumps use different impellers.
Quick visual check before ordering saves a lot of headaches 👍
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.