Johnson Pump F6B-9 Bronze Raw-Water Pump 10-24946-01 | Crankshaft-Driven | GM Marine

Johnson Pump F6B-9 Bronze Raw-Water Pump — 10-24946-01

Part Number: 10-24946-01 (Johnson Pump)  |  Series: F6B-9  |  Brand: Johnson Pump / SPX Flow

Johnson Pump 10-24946-01 (F6B-9) is a crankshaft-driven bronze flexible-impeller raw-water pump for selected GM-based marine gasoline engine cooling systems. It features a bronze pump body, stainless-steel shaft, flange mounting, and vertical 1-1/4 in. ports, and is designed to restore full raw-water flow through the engine cooling circuit when the original pump is worn, leaking, or damaged.

The F6B-9 series is designed for approximately 15% greater flow compared to the earlier F6B configuration. The replacement impeller for this pump is Johnson Pump 09-812B-1.

Specifications

• Manufacturer Part Number: 10-24946-01
• Catalog / SKU Reference: 10249601 / 189-10249601
• Brand: Johnson Pump / SPX Flow
• Series: F6B-9
• Product Type: Crankshaft-Driven Bronze Flexible-Impeller Raw-Water Pump
• Pump Body: Bronze
• Shaft: Stainless steel
• Mounting Style: Flange-mounted
• Port Orientation: Vertical
• Port Size: 1-1/4 in. (31.8 mm)
• Replacement Impeller: 09-812B-1 / 09812B1
• System: Marine engine raw-water (seawater) cooling circuit
• Weight: 2,028 g / approx. 4.5 lb

Compatible Applications

Fitment is confirmed by the existing pump number and mounting configuration — not by engine displacement or brand alone. GM-based marine engines can use several crankshaft-driven seawater pumps that appear similar but differ in port size, flange pattern, shaft arrangement, and impeller specification. Documented applications include:

• Volvo Penta GM-based gasoline marine engines
• Indmar marine engines
• Marine Power engines
• PCM / Pleasurecraft Marine engines
• Selected small-block and big-block GM marine engine installations

Broader catalog references also associate the F6B-9 pump family with selected Ford and Alaska Diesel installations. Confirm by the original pump number and mounting layout before ordering.

Fitment Notice

Before ordering, confirm all of the following for your application:

• Existing pump is stamped or listed as F6B-9 or cross-references 10-24946-01 / 10249601
• Port size is 1-1/4 in. (31.8 mm)
• Mounting is crankshaft-driven, flange-style
• Port orientation is vertical
• Replacement impeller required is 09-812B-1 / 09812B1

Do not select this pump by engine displacement alone. Several Johnson Pump F-series models share a similar appearance but are not interchangeable.

When to Replace the Pump

Replace the complete raw-water pump when any of the following are observed:

• Water leaks from the pump shaft seal or pump body
• Shaft or bearing play is present, or the bearing is noisy
• Bronze housing is scored, badly worn, or damaged
• Raw-water flow remains weak after a fresh impeller is installed
• Repeated impeller failures suggest internal housing wear or roughness
• Corrosion or mechanical damage affects the pump flanges or sealing surfaces

Installation Notes

• Inspect the crankshaft drive surface, pump flange, hoses, clamps, and surrounding cooling components before installation
• Confirm the pump is correctly aligned with the engine crankshaft drive before securing the flange
• Connect the 1-1/4 in. (31.8 mm) inlet and outlet hoses and secure all clamps
• Install a fresh 09-812B-1 impeller if not supplied with the pump, following the impeller installation procedure for the F6B series
• Verify free pump rotation by hand before starting the engine
• If the previous impeller lost blade material, inspect all downstream passages — oil coolers, heat exchangers, thermostat housings, and hoses — before startup
• Run the engine and confirm strong raw-water discharge, correct engine temperature, and no leaks at the pump body, cover plate, or hose connections

Cross-Reference Part Numbers

• Johnson Pump: 10-24946-01
• Also listed as: 10249601 / 189-10249601 / 189-102494601
• Pump Series: F6B-9
• Replacement Impeller: 09-812B-1 / 09812B1

Related Products

• Johnson Pump 09-812B-1 Impeller Kit (F6) — correct replacement impeller for the F6B-9 pump
• Johnson Pump 09812BT1 Kit: F6 Impeller w/Thread MC97 — F6 impeller kit with thread insert for specific installations
• Johnson Pump 09-45587 Service Kit — F6 series service kit
• Johnson Pump 09-45585 Service Kit For F5B-8/8007 — related F5B service kit for reference
• ARCO WP003 Volvo Penta / Indmar Ford 351 Replacement Water Pump — complete pump alternative for applicable Volvo Penta / Indmar installations
• ARCO WP002 Volvo Penta / Indmar Ford 302 Replacement Water Pump — related ARCO pump for Ford 302 / Volvo Penta applications

Parts Desk Insights

Best use case: The F6B-9 is the right pump when a Volvo Penta GM-based, Indmar, Marine Power, or PCM engine has a failed or leaking crankshaft-driven seawater pump and the original pump cross-references 10-24946-01. It’s a complete bronze assembly — not a rebuild — so you’re starting fresh with a new housing, shaft, and seals rather than hoping the old housing is still serviceable. The 15% flow improvement over the earlier F6B version is a meaningful gain if the cooling system was running warm before the pump failed.

Common issues: The most common ordering mistake is confusing the F6B-9 with other F-series pumps that look nearly identical. The 1-1/4 in. port size and vertical port orientation are the key identifiers — if the original pump has smaller ports or horizontal orientation, it’s a different model. Always confirm against the existing pump number or your engine’s parts diagram. The second issue is neglecting to inspect the pump housing bore when replacing just the impeller on a high-hour pump: if the bore is scored or oval, new impellers will fail prematurely regardless of quality. When in doubt on a high-hour engine, replace the complete pump at the same time as the impeller.