UNI FILTER NU-8604ST Air Filter for Artic Cat 250/300 1998-2005 Models Made in USA

OVERVIEW

The UNI Filter NU-8604ST is a reusable two-stage air filter designed to deliver consistent airflow while trapping dirt and contaminants for routine maintenance on your ATV.

Built with a construction that allows layers to separate for thorough cleaning, this filter offers an OEM-style replacement solution that mounts directly into the stock airbox.

Fabricated in the U.S.A. with attention to durability, the element supports repeated washing and oiling while relying on a sealing surface feature to help maintain a positive fit against the airbox mating interface for optimal engine protection on 1998–2005 Arctic Cat machines.

ENGINEERING & PERFORMANCE

Performance relies on a two-stage architecture where the filter components detach completely, enabling maximum airflow passage and simplifying the removal of trapped debris during regular service intervals.

Daily operation benefits from the ability to clean the media with standard grease-cutting dishwashing detergent followed by re-oiling, which preserves filtration efficiency without discarding the unit after a single use cycle.

Sealing consistency is supported by the inclusion of an Ultra Seal grease groove on the filtering surface, which aids in creating a restricted boundary to prevent unfiltered air entry around the perimeter.

The physical dimensions and profile adhere to OEM specifications, ensuring the element seats securely within the original air intake housing and maintains correct pressure characteristics across the operating range.

KEY FEATURES

• Air filter
• Reusable / washable design
• Model‑specific fitment
• OEM‑style replacement
• Made in the USA

TECHNICAL SPECIFICATIONS

• Brand: UNI
• Part Name: NU-8604ST
• Filter Type: Air
• Supported Years: 1998–2005
• Compatible Trims: 250 4x2, 250 4x4, 300 4x4, 300 4x2

FITMENT

• Arctic Cat 250 4x2 (1999–2005)
• Arctic Cat 250 4x4 (1999–2005)
• Arctic Cat 300 4x4 (1998–2005)
• Arctic Cat 300 4x2 (1998–2005)

WHY RIDERS CHOOSE THIS

Riders select this air filter because the removable two-stage design maximizes airflow capacity while retaining dirt, letting the layers pull apart for deep cleaning that restores performance without compromising filtration integrity.

The straightforward maintenance workflow—cleansing with dish soap and re-oiling—keeps the element ready for extended tracking seasons, while the Ultra Seal groove assists in maintaining a tight mount to guard against dust ingress.

Fitting precisely into the factory airbox, this filter eliminates compatibility worries and delivers the same mechanical parameters as the stock unit, which translates to predictable throttle response and stable engine operation.

Manufactured stateside, the build reliability meets the expectations of ATV operators who require a resilient component that handles abrasive trail environments and reduces the frequency of unexpected air filter replacements.