RFX Foam Air Filter FXAF4000455NO - Yamaha YZ250F / YZ450F / WR250F 2010-2019

Product Description

The RFX Air Filter provides high-capacity intake filtration and smooth airflow for Yamaha four-stroke motocross and off-road models. Manufactured by Multi Air, this twin-layer foam air filter lets your engine breathe cleanly while maintaining a protective barrier against airborne roost, sand, and fine trail dust.

Engineered with breathable twin-layered foam, the coarse outer layer captures larger mud, grit, and roost, while the dense inner layer catches micro-particulates before they can enter the intake boot. Built using flame-retardant nonflammable foam suited for four-stroke applications, it provides an exact airbox fitment developed through Multi Air's 30-plus years of off-road competition experience.

Top Features: RFX Foam Air Filter

• Breathable twin-layer foam construction delivers steady intake airflow while stopping fine silt and dust.
• Nonflammable flame-retardant foam provides added safety against backfire combustion on four-stroke models.
• Precision-molded sealing base ensures a snug, gap-free seal against the Yamaha airbox housing.
• Developed and manufactured by Multi Air with over 30 years of off-road racing filtration experience.

Please review the detailed compatibility data below to ensure an exact fitment match for your motorcycle before finalizing your purchase.

Fitment List

Frequently Asked Questions

Q: Does this RFX air filter come pre-oiled or dry?
A: This filter (MPN FXAF4000455NO) is supplied dry (un-oiled) and must be properly treated with foam air filter oil prior to installation.

Q: Why is nonflammable foam used on 4-stroke models?
A: Four-stroke powerplants can backfire through the intake tract. Nonflammable foam helps prevent backfire sparks from igniting the filter media or oil.

Q: Who manufactures these air filters for RFX?
A: RFX air filters are manufactured by Multi Air, an industry leader with over 30 years of air filter production experience.

Expert Pro-Tip: When oiling a dry foam air filter, work foam filter oil thoroughly through both foam layers until the color is completely uniform across the entire surface. Gently squeeze out any excess oil without twisting or wringing the seams, and allow the carrier solvent to evaporate for 15 minutes before seating the filter cage into the Yamaha airbox.

Recommended Pairings:

• Yamaha YZ250F Performance Parts & Accessories
• Yamaha YZ450F Performance Parts & Upgrades
• Air Filter Cleaners & Maintenance Chemicals

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