SouthMarine Neoprene 12-Blade Water Pump Impeller for Johnson 09-812B / Yamaha 6TA-12457-00 — Brass Hub, 12-Tooth Spline, 2.25" Di

SouthMarine's neoprene 12-blade water pump impeller is a direct-fit replacement for Johnson 09-812B / 09-812B-1 and Yamaha 6TA-12457-00 applications, featuring a brass hub and 12-tooth spline drive for reliable engine cooling circulation.

This impeller is designed for inboard marine cooling systems that require a compact, durable rotor to move seawater through heat exchangers and jackets. Built from neoprene with a brass hub and a 12-tooth spline, the unit measures 2.25" (57.1 mm) in diameter and 1.90" (48.2 mm) in depth and fits a 5/8" (16 mm) shaft. It replaces a wide range of original-equipment and aftermarket part numbers across Johnson, Yamaha, Volvo Penta, Jabsco and more, making it a versatile spare for engine maintenance or seasonal service.

Will this impeller fit my Johnson or Yamaha engine?

Yes—this SouthMarine impeller is made to match the dimensions and spline count of the Johnson 09-812B / 09-812B-1 and Yamaha 6TA-12457-00 originals. Confirm the physical measurements and spline count on your current impeller before installation.

• Diameter: 2.25" (57.1 mm)
• Depth: 1.90" (48.2 mm)
• Shaft size: 5/8" (16 mm)
• Spline drive: 12-tooth

What materials and construction qualities does this impeller have?

The rotor blades are molded from durable neoprene to resist flex fatigue in freshwater and saltwater environments, while the central brass hub provides secure mounting to the drive shaft. The 12-blade layout improves water flow consistency and reduces vibration compared with fewer-blade designs.

• Neoprene blade material for flexibility and wear resistance
• Brass hub for corrosion resistance and stable fit
• 12 blades to maintain steady pump output and lower pulsation
• Precision spline to minimize slippage on the shaft

How does this impeller compare to other replacement part numbers?

SouthMarine’s impeller is manufactured to match OEM geometry and fits a variety of equivalent part numbers across multiple brands, so it can replace several commonly stocked items without modifying the pump housing. It's intended as a direct swap for many Johnson, Yamaha, Volvo Penta, Jabsco, Sierra and other inboard impellers listed by cross-reference.

• Replaces Johnson 09-812B and 09-812B-1
• Compatible with Yamaha 6TA-12457-00 and Sierra 18-3306
• Fits Volvo Penta references like 21951354 and 21951352
• Also cross-references Jabsco 13554-0001 and Indmar S685007

What should I check during installation and maintenance?

Inspect the impeller housing, drive key or spline, and inlet/outlet hoses when replacing the impeller. Proper seating, lubrication with a water pump lubricant or light silicone grease, and verifying rotation direction ensure the pump performs correctly after installation.

• Check pump housing for corrosion or scoring
• Confirm spline engagement and hub tightness
• Lubricate blades lightly for easier insertion
• Run the engine briefly to verify steady water flow and no leaks

Who is this for: Boaters, mechanics and fleet managers who need a reliable, OEM-compatible replacement impeller for small- and medium-displacement inboard engines will find this SouthMarine unit useful. It's ideal as a seasonal service part or emergency spare for vessels using Johnson, Yamaha, Volvo Penta, Jabsco and similar cooling systems. Purchase this impeller if you want a direct-fit neoprene rotor with a brass hub, 12-blade design and 12-tooth spline for a 5/8" shaft.