Johnson Pump 09-808B-1 F35 Impeller Kit | MC97 / EPDM | 40 × 19 mm | Replaces Jabsco 22405-0001

Johnson Pump 09-808B-1 F35 Impeller Kit — MC97 / EPDM

Part Number: 09-808B-1 (Johnson Pump / SPX Flow)  |  Pump Family: F35  |  Brand: Johnson Pump / SPX Flow

Johnson Pump 09-808B-1 is a genuine MC97/EPDM flexible impeller kit for Johnson Pump F35-series marine raw-water pumps. The kit is designed for engine-cooling and generator-cooling service, where the impeller draws raw water through the pump to maintain cooling-water circulation from startup through continuous operation.

SPX Flow’s official specification confirms 40 mm (1.58 in.) outside diameter × 19 mm (0.75 in.) width × 12 mm (0.47 in.) hub diameter, six blades, and a direct cross-reference to Jabsco 22405-0001. The kit includes an O-ring, gasket, and impeller lubricant for a complete pump service.

Fitment note: Johnson also produces an F35 impeller 09-806B-1 with the same 40 mm outside diameter but a different hub dimension. Outside diameter alone is not sufficient to distinguish these two impellers — confirm the full part number, hub size, and width before ordering.

Specifications

• Part Number: 09-808B-1
• Brand: Johnson Pump / SPX Flow
• Pump Family: F35
• Product Type: Flexible Raw-Water Pump Impeller Kit
• Material: MC97 / EPDM
• Outside Diameter: 40 mm / 1.58 in.
• Width: 19 mm / 0.75 in. (official SPX specification)
• Hub / Shaft Diameter: 12 mm / 0.47 in.
• Number of Blades: 6
• Kit Contents: Impeller, O-ring, gasket, impeller lubricant
• UPC: 7330717008734
• Weight: 113 g / approx. 4 oz

Compatible Applications

Johnson Pump identifies 09-808B-1 for F35-series pumps. Confirm fitment by the existing pump and impeller number. Documented applications include:

• Volvo Penta MB / MD marine diesel engines (cross-reference: 875583-7 / 833995)
• Onan 5.5 MDKUB marine generator
• Onan 6.0 MDKOB marine generator
• Onan 6.5 MDKUB marine generator
• Onan 7.5 MDKOB marine generator
• Onan 9.0 MDKOB marine generator
• Selected Westerbeke generator applications using the F35 pump configuration
• Selected Perkins and Kubota small-diesel installations using this F35 impeller

Fitment Notice

Before ordering, confirm all of the following match your pump and original impeller:

• Pump is a Johnson Pump F35 series
• Original impeller number is 09-808B-1 or cross-reference Jabsco 22405-0001
• Outside diameter: 40 mm (1.58 in.)
• Width: 19 mm (0.75 in.) — not 0.57 in. as some third-party listings incorrectly state
• Hub diameter: 12 mm (0.47 in.)
• Blade count: 6 blades

The 09-806B-1 is a different F35 impeller with the same 40 mm OD but a different hub — do not substitute.

When to Replace the Impeller

Replace the impeller when any of the following are found:

• Blades are cracked, torn, split, or hardened
• Vanes remain permanently bent after the pump stops
• Blade tips are missing or broken off
• Raw-water flow through the cooling system has decreased
• Engine or generator operating temperature begins rising above normal
• The pump has been operated without water (dry run)
• The impeller’s service history is unknown or overdue for scheduled maintenance

Johnson Pump recommends regular impeller service because blade condition is critical to maintaining proper cooling flow from cold startup through continuous operation.

Installation Notes

• Close the raw-water intake seacock or isolate the water supply before opening the pump
• Remove the pump cover and extract the old impeller — do not score the pump housing bore
• Inspect the cover plate, cam, shaft, housing bore, and all sealing surfaces for wear or damage
• Account for all blades from the old impeller — if any are missing, inspect downstream hoses, heat exchangers, and cooling passages before restarting
• Apply the supplied impeller lubricant to the new impeller blades and hub before installation
• Install the replacement gasket or O-ring supplied in the kit
• Refit the pump cover and tighten evenly
• Open the water supply and start the engine or generator — verify strong raw-water flow and inspect the pump for leaks immediately after startup

Cross-Reference Part Numbers

• Johnson Pump: 09-808B-1 / 09808B1
• Jabsco: 22405-0001
• Volvo Penta: 875583-7 / 833995
• Vetus: IMP00601
• UPC: 7330717008734

Related Products

• Johnson Pump 09-806B-1 Impeller Kit — alternate F35 impeller with same 40mm OD but different hub — confirm part number before ordering
• Johnson Pump 09-808B-1 Impeller Kit — alternate listing for this same impeller
• Johnson Pump 09-808B-1 MC97 Impeller For F35 Pumps — alternate listing for this same impeller
• Seachoice F35 Impeller Kit 17788 | Johnson 09-808B-1 / Jabsco 22405-0001 — aftermarket equivalent for F35
• Johnson Pump 09-45587 Service Kit — F6 series service kit for reference
• Johnson Pump 09-812B-1 Impeller Kit (F6) — F6 series impeller for larger Johnson Pump applications

Parts Desk Insights

Best use case: 09-808B-1 is the correct service impeller for Onan marine gensets (MDKUB / MDKOB series) and Volvo Penta MB/MD diesel engines using the Johnson F35 raw-water pump. These are common generator-equipped cruising and workboat installations, and the F35 is a small, durable pump that gives long service when the impeller is replaced on schedule. The MC97/EPDM compound resists swelling and fatigue better than some other elastomers, which is one reason Johnson specifies it for continuous-duty generator cooling applications.

Common issues: The most frequent ordering error is confusing 09-808B-1 with 09-806B-1 — both are F35 impellers with the same 40 mm outside diameter, but the hub dimensions differ and they are not interchangeable. Always confirm the full part number. The second issue is the incorrect width specification that circulates in some third-party catalog data; the official SPX Flow dimension is 19 mm (0.75 in.), not 0.57 in. Use the pump part number and impeller number together — not the diameter alone — to confirm the right kit.