Sprint Filter P08 F1-85 Air Filter for Racing – CFMOTO NK 250 (2018–2019) PM227S F1-85

Everything about fitting this element is identical to fitting the road one: the same frame, the same outline, the same seat in the CFMOTO NK 250 airbox, the same absence of oil, the same few minutes with the cover off. That similarity is the practical case for the PM227S F1-85, and it is a narrow case. The medium is a racing cloth — 85 microns at a rated 15,000 l/m²/sec against the road weave's 80 microns and 5,050 — and it makes sense as a second element kept for events, rather than as the panel a bike carries through a year of commuting.

Key Features

• The racing member of the P08 family: an 85 micron aperture, rated 15,000 l/m²/sec
• Interchangeable with the road element in the same housing, in a few minutes
• Dry polyester, never oiled, serviced with a compressor like the rest of the range
• Approximately double the filtering surface of a normal performance element
• No adaptor, no modification and no remapping in either direction of the swap
• Two-year warranty and a service life measured against the motorcycle's own

Two cloths, one airbox

Sprint Filter builds these elements to the housing, which means the choice of medium is not a commitment. A rider whose machine sees both kinds of use can run the road panel all year and fit this one for a track weekend, then put the first back afterwards. The box does not know the difference and the engine management does not either, since neither the aperture nor the flow rating is a value the fuelling was calibrated against. What the arrangement buys is the ability to accept coarser filtration only in the places where the air is clean enough to make it a fair exchange.

Before buying a second element

Do the arithmetic first, because this one asks close to three times what the standard element for the same box does. On a 250 ridden on the road it changes nothing measurable: a drop-in filter does not make a standard NK 250 noticeably stronger, and the extra rated flow sits behind an unmodified airbox and unmodified mapping with nothing to draw it out. The case for owning both is a case about circuits, and about an engine that has already been worked on. Where neither applies, the road element on its own is the complete answer.

Care and cleaning

Both elements for this airbox are looked after the same way, which is part of what makes swapping them simple. Compressed air on the clean side, driven outward, clears the PM227S F1-85 in the usual case. Where a weekend has left a film, lukewarm water with mild detergent lifts it, rinsed until the water runs clear. Drying is by air alone and takes as long as it takes; heat of any kind spoils polyester, and a damp panel must never go back in. The maintenance sheet is in the Downloads tab.

Fitment & Compatibility

The racing element for the CFMOTO NK 250 of 2018 and 2019. Three CFMOTO machines share this part number in the Sprint Filter listing; the full list is in the Fitment tab.