AR RKA-J-F22 is a specialty solid shaft pump designed specifically for use with engines that include an internal gear reduction system. Optimized for Honda GX390 K1 engines (and variations such as LX2), this model is ideal for contractors and OEMs requiring reliable high-pressure output in a compact, specialty configuration. The 25 mm shaft with a 2:1 gear reduction allows seamless integration with gasoline engines in professional-grade equipment.

Built with a nickel-plated brass head and bronze connecting rods, the RKA-J-F22 delivers enhanced corrosion resistance and long-lasting durability under heavy loads. At 1750 RPM, the pump produces up to 15.1 L/min (4.0 GPM) at 4000 PSI, making it suitable for demanding cleaning and surface preparation jobs. The compact design, combined with its specialty engine-mount flange, makes this unit a trusted choice for engine-driven washdown systems, industrial cleaning machines, and pressure washer OEM builds.

Key Features & Technical Highlights

• Flow: 4.0 GPM (15.1 L/min)
• Pressure: 4000 PSI (275 bar)
• Speed: 1750 RPM
• Shaft: 25 mm solid shaft, 2:1 gear reduction
• Engine Compatibility: Fits Honda GX390 (K1) and LX2 variations
• Construction:
  • Nickel-plated brass pump head for corrosion resistance
  • Bronze connecting rods for added durability
  • Oversized oil reservoir for improved cooling (15 oz capacity)
• Temperature Limit: 140°F standard, with optional high-temp kits up to 180°F

Available Model

RKA4G40JH-F22 – 4.0 GPM @ 4000 PSI, 1750 RPM, 25 mm shaft

Applications

• Contractor-grade pressure washers – heavy-duty cleaning for concrete, fleets, and equipment
• OEM equipment integration – built for Honda GX390-powered machines
• Surface preparation – paint stripping, graffiti removal, and concrete washdown
• Agricultural washdown – equipment, barns, and livestock facilities
• Industrial cleaning rigs – portable and trailer-mounted engine-driven systems

Optional Kits & Parts

• Viton water seals (Ø 18) for chemical and hot water resistance
• High temperature kit (up to 180°F) for demanding applications
• Single cylinder piston kit for quick field repairs
• Comprehensive repair kits (valves, pistons, seals, support rings, and oil seals)

For additional industry standards and technical resources, visit: https://www.pumps.org/