KÄRCHER FJ6 Foam Cannon for K1–K5 Pressure Washers — 20 oz Tank, Adjustable Dosing & Spray

The Kärcher FJ6 Foam Cannon converts compatible Kärcher electric pressure washers into a thick, clinging foam sprayer for easier vehicle and outdoor surface cleaning.

Designed for home users who want faster, more effective pre-wash coverage, the FJ6 attaches directly to the trigger gun of Kärcher K1–K5 electric models and delivers a dense detergent blanket that loosens dirt and grime before rinsing. The onboard dosing dial and adjustable jet let you control foam thickness and flow, while the generously sized 20-ounce reservoir reduces refill frequency during multi-vehicle or larger surface jobs.

How do I set up the FJ6 with my Kärcher pressure washer?

Setup is straightforward: fill the tank with compatible detergent (dilute if concentrated), attach the foam cannon to the Karcher trigger gun, then adjust the yellow dosing dial and spray pattern to suit the job. If your electric unit predates 2010, a separate Adapter M may be required.

• Fill tank with Kärcher detergent; add water for concentrates
• Push foam cannon onto the trigger gun connection of K1–K5 models
• Turn the yellow dial to set detergent dose
• Twist nozzle to change jet width and foam density

What surfaces and vehicles can the foam cannon clean effectively?

The FJ6 is versatile — ideal for cars, motorcycles, bicycles, RVs and patio furniture, plus many hard exterior surfaces. Use foam as a pre-soak on painted surfaces, siding, patios and driveways to help lift dirt before hand-washing or pressure rinsing.

• Cars, trucks, motorcycles and bicycles
• RV exteriors and camper surfaces
• Garden furniture, patios, walls, paths and driveways
• House siding and stairways for light to moderate grime

Which Kärcher machines are compatible and what are the limitations?

The FJ6 is made for Kärcher electric pressure washer models K1 through K5. It does not work with older unadapted units or with certain compact or gas models; specifically, K1700–K2300 electric and all gas pressure washers are not compatible.

• Compatible: Kärcher K1, K2, K3, K4, K5 electric washers
• Not compatible: Kärcher K1700–K2300 electric and gas pressure washers
• Older electric models (pre-2010) may need Adapter M (part 2.643-950.0)
• Simple mechanical attachment—no electrical connections required

How do I control foam thickness and detergent use to avoid waste?

The FJ6 has two user controls: a yellow dosing dial for detergent concentration and a nozzle adjustment for the spray/jet level. These let you fine-tune foam output so you use only the amount needed for the task, saving detergent and avoiding runoff.

• Turn the yellow dial to increase or decrease detergent feed
• Adjust nozzle angle for broader coverage or targeted jets
• Use diluted detergent when recommended to reduce residue
• Rinse thoroughly after foaming to remove cleaning agents

Who is this for? The Kärcher FJ6 Foam Cannon is aimed at homeowners and enthusiasts who own a compatible Kärcher K1–K5 electric pressure washer and want a quicker, more even way to apply cleaning detergent. It suits people who wash multiple vehicles, tackle outdoor furniture and hardscaping, or who prefer a foaming pre-wash step to help reduce scrubbing time. If you have an incompatible Kärcher model or rely on a gas-powered washer, choose a different foam attachment designed for that system.