Water Pump Impeller Kit – Fits Indmar (320HP-350HP), Volvo Penta, Yanmar (Replaces 09-812B-1, S685007)
Water Pump Impeller Kit – Fits Indmar (320HP-350HP), Volvo Penta, Yanmar (Replaces 09-812B-1, S685007) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Water Pump Impeller Kit – Fits Indmar (320HP-350HP), Volvo Penta, Y...
Product Details
This Water Pump Impeller Kit – Fits Johnson F6B-9 Series Pumps is an essential service part for maintaining your marine engine's cooling system. It is designed for Indmar Monsoon, Hammerhead, and Raptor engines (320HP–350HP) that utilize a Johnson F6B-9 series pump, and is also compatible with select Volvo Penta and Yanmar marine engines.
This kit serves as a direct interchange for Johnson 09-812B-1, Indmar S685007, Sierra 18-3306, Yanmar 119773-42600, Jabsco 13554-0001-P, and others, ensuring broad compatibility.
- Engineered for direct replacement installation.
- Made from durable neoprene rubber with a solid brass insert for reliable service.
- Kit includes the essential impeller, O-ring, and gasket for a complete service.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Johnson | 09-812B-1 / 09-812B |
| Indmar | S685007 / 685001 |
| Sierra | 18-3306 |
| Yanmar | 119773-42600 |
| Jabsco | 13554-0001-P |
| Yamaha | 6TA-12457-00 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This impeller is designed for Indmar Monsoon, Hammerhead, and Raptor engines commonly found in Supra, Moomba, Mastercraft, and Tige towboats.
Fits the Yanmar ME420TI marine diesel engine.
| Brand | Model | Rated HP | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|---|
| Indmar | Monsoon | 320HP | 4-Stroke | S685007 | Found in Supra, Moomba, Mastercraft & Tige boats |
| Indmar | Monsoon | 325HP | 4-Stroke | S685007 | Found in Supra, Moomba, Mastercraft & Tige boats |
| Indmar | Monsoon | 330HP | 4-Stroke | S685007 | Found in Supra, Moomba, Mastercraft & Tige boats |
| Indmar | Monsoon | 335HP | 4-Stroke | S685007 | Found in Supra, Moomba, Mastercraft & Tige boats |
| Indmar | Monsoon | 340HP | 4-Stroke | S685007 | Found in Supra, Moomba, Mastercraft & Tige boats |
| Indmar | Monsoon | 350HP | 4-Stroke | S685007 | Found in Supra, Moomba, Mastercraft & Tige boats |
| Indmar | Hammerhead | 4-Stroke | S685007 | ||
| Indmar | Raptor | 4-Stroke | S685007 | ||
| Yanmar | ME420TI | 4-Stroke | 119773-42600 |
Technical Specs
- Product Type
- Water Pump Impeller Kit
- Installation
- Direct replacement
- Impeller Material
- Neoprene rubber with brass insert
- Impeller Design
- 12 blades with spline drive
- Impeller Dimensions
- 2-1/4" OD × 1-15/16" width (57.15 mm × 49.21 mm)
- Shaft Type
- 5/8" spline drive brass insert
- Kit Contents
- Impeller, O-ring, and gasket
- Compatible Pumps
- Johnson F6B-9, 10-24232-1, 10-24915-01, Jabsco 50410-1201
- Warranty
- Varies by retailer (typically 90 days)
What’s in the Box
- 1 x Impeller (Neoprene + Brass) 12 Blades OD 2-1/4" x 1-15/16" Wide Spline Drive
- 1 x O-Ring
- 1 x Gasket
Installation Notes
- Close the engine's raw water intake valve (seacock).
- Locate the raw water pump and remove the screws from the end cover plate.
- Carefully pry off the cover plate. Note the direction the old impeller blades are bent.
- Remove the old impeller using an impeller puller or two pairs of pliers. Avoid gouging the pump housing.
- Clean any debris or old gasket material from the pump housing and cover plate. Inspect for scoring or damage.
- Install the new O-ring or gasket on the pump body.
- Lubricate the inside of the pump housing and the new impeller with a water-based lubricant or dish soap.
- Insert the new impeller while turning the engine crankshaft in its normal direction of rotation to correctly bend the blades.
- Secure the cover plate with its screws, tightening them evenly.
- Open the seacock, start the engine, and immediately check for leaks around the pump cover.
Troubleshooting & FAQ
How do I know if this impeller will fit my engine?
The best way to ensure fitment is to check your engine's service manual or existing impeller for a part number. Cross-reference that number with the ones listed in our Part Number Matrix. You can also verify compatibility by matching your engine model and year in the compatibility table.
What are the signs of a failing water pump impeller?
Common signs include a higher-than-normal engine temperature, reduced water flow from the exhaust outlet, visible cracks or missing blades on the impeller, and a stiff or brittle texture when flexing the blades.
How often should I replace my boat's impeller?
As a general rule, replace your impeller every 1-2 years or every 100-200 hours of engine use, whichever comes first. However, always follow your engine manufacturer's specific service recommendations. Annual inspection is highly recommended, especially for boats used in saltwater or sandy/silty conditions.
Is a special tool required for installation?
While not always required, an impeller puller can make removal much easier and safer, reducing the risk of damaging the pump housing. Pliers can often be used, but require more care.
What is the purpose of the O-ring and gasket?
The O-ring or gasket creates a watertight seal between the pump body and the end cover plate. It is critical to use the new seal provided in the kit to prevent leaks, which could lead to pump damage or engine overheating.
What is the difference between this impeller and an OEM part?
This is an aftermarket part designed to meet or exceed OEM specifications for fit, form, and function. It is made with comparable high-quality materials (neoprene and brass) to ensure reliable performance in marine environments.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
Payment & Security
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