K&N Fuel Filter 81-0221 1/4" Flange — High‑Volume Backflushable Inline Filter

K&N 81-0221 Fuel Filter is a high-volume, low-pressure inline fuel filter designed for easy backflushing and long service life.

The K&N 81-0221 fuel filter combines a simple design with durable materials to protect fuel systems from debris while maintaining strong flow for many applications. It is offered with a 1/4" flange and sold individually or in 12-packs. Note: this part is not legal for sale or use in California on any pollution-controlled motor vehicle.

How does the K&N 81-0221 keep fuel systems clean?

The 81-0221 traps particles and contaminants before they reach injectors, carburetors, or pumps, reducing the risk of clogging. Its construction supports effective filtration without significantly restricting flow, making it suitable for engines that require steady fuel delivery.

• High-volume, low-pressure design for steady throughput
• Filtration media that captures debris while preserving flow
• Inline placement prevents contaminants from reaching downstream components

Can I service this filter myself and how?

Yes — the K&N 81-0221 is designed to be cleaned by backflushing, a straightforward maintenance step that restores flow and extends service intervals. Backflushing dislodges trapped particles so the filter can be put back into use quickly.

• Backflushable construction for reusable maintenance
• No special tools required for routine cleaning
• Cleaning frequency depends on operating conditions and fuel quality

What configurations and sizes are available?

The product is available with a 1/4" flange connection and can be purchased as a single unit or in a 12-pack for fleet or multi-vehicle servicing. The compact inline form factor fits many common fuel lines and mounting setups.

• Option with a 1/4" flange for direct hose or line connection
• Single-unit purchase or bulk 12-pack for convenience
• Compact inline shape fits tight engine compartments

Are there any legal or application limitations I should know about?

This filter is intended for general fuel-system protection but may be subject to regional restrictions. Specifically, the K&N 81-0221 is not legal for sale or use in California on any pollution-controlled motor vehicle — check local regulations before purchasing for on-road use in restricted areas.

• Not legal for sale or use in California on pollution-controlled vehicles
• Suitable for off-road, retrofit, and many aftermarket applications where allowed
• Confirm compatibility with fuel type and engine requirements before installation

Who is this for: Mechanics, DIY enthusiasts, fleet managers, and anyone needing a reliable, serviceable inline fuel filter for engines that require steady fuel flow. Choose a single unit for one-off replacements or a 12-pack for workshops and multiple-vehicle maintenance; avoid use in California pollution-controlled vehicles because of legal restrictions.