Johnson Pump 09-810B-9 F4B Impeller (Nitrile)

The Johnson Pump 09-810B-9 F4B Impeller in Nitrile is a critical replacement component for marine cooling systems that demand reliability on the water. Whether you're running a fishing boat, cruiser, or work vessel, a worn or damaged impeller can silently compromise your engine's cooling efficiency, leading to overheating, system failure, or catastrophic engine damage. This OEM-quality impeller is engineered to restore full flow capacity to your F4 pump, ensuring consistent water circulation through your engine block under varying sea conditions and throttle demands.

Built from durable Nitrile (oil-resistant) material, the Johnson Pump impeller resists degradation from fuel, saltwater exposure, and thermal cycling—conditions that cause standard rubber impellers to crack, harden, and lose priming ability. The F4B design features a 2.0-inch outer diameter with 0.47-inch inner bore and 0.87-inch width, precisely dimensioned to deliver maximum flow without creating cavitation. SPX's Johnson Pump brand impellers are developed to OEM standards and designed to maintain peak performance across a range of engine sizes and cooling demands, making them a trusted choice for anglers and boat operators who cannot afford downtime.

This impeller is ideal for boat owners who service their own engines or work with marine mechanics to maintain vessels that spend significant time on freshwater and saltwater. Installation is straightforward for anyone familiar with basic pump disassembly, and the Nitrile composition ensures longer service life than conventional impellers in harsh marine environments. If your engine is running hot, you're hearing cavitation noise, or your impeller hasn't been replaced in over two seasons, the Johnson Pump 09-810B-9 F4B Impeller is the essential maintenance item that keeps your cooling system functioning like new. Compatible with F4 pump assemblies across multiple Johnson and Evinrude marine engine platforms.