Sprint Filter P08 F1-85 Air Filter for Racing – CFMOTO NK 675 (2025–2026) SM290S F1-85

What sends most people looking at a racing element is a feeling rather than a figure: the bike does not pull the way it used to. Nine times in ten the explanation is dull — a panel well into its service life, restricting a little more every thousand kilometres, with nothing on the dashboard to report it. A racing medium is not the cure for that, because a clean standard element already is. Both cloths Sprint Filter offers for the CFMOTO NK 675 airbox go back to their starting condition under an air line. Only one of them asks a little over two and a half times what the other does.

Key Features

• The racing member of the P08 family: 85 microns at a rated 15,000 l/m²/sec
• Retention quoted by Sprint Filter at 95.22 % of 100-micron test particles
• Dry polyester, oil-free when new and oil-free after every wash
• Around twice the filtering surface of the elements it is compared against
• Fits the standard NK 675 airbox as it is; nothing adapted, nothing remapped
• Restored with compressed air, covered by two years of warranty

Condition, not specification

A rating describes a filter on the day it was measured, which is to say clean. Everything a rider actually notices happens afterwards, as the material loads and the restriction climbs, and that curve belongs to the panel's condition rather than to its specification. Both media for this housing are dry, both are washed and refitted, and both start again from the same place when they are. So the flat-feeling motorcycle is answered by opening the airbox rather than by ordering the dearer cloth, and that answer costs nothing but an afternoon.

When it is the right element anyway

There is a real case for this one, and it is narrow. It fits an NK 675 that spends real time at full throttle on a circuit, with maintenance counted in sessions and an intake and exhaust already opened up. Under those conditions a wider opening is inspected long before it can matter and a very high flow figure has something to answer. Away from them the standard weave is the better part and filters slightly finer for it. In neither case does the element add output: a drop-in filter does not make a standard NK 675 noticeably stronger.

Care and cleaning

The servicing here is deliberately dull. A compressed-air line held to the clean side of the SM290S F1-85 and moved across the panel drives the load back out through the face that gathered it, and in most cases that is the whole job. If a session leaves a film the air will not take, lukewarm water and a trace of mild detergent will, followed by a rinse until it comes away clear. Drying is by air at room temperature for as long as that takes — a heat gun or a flame ruins polyester — and the element is refitted dry, with no oil, dressing or solvent added at any stage. The maintenance sheet is in the Downloads tab.

Fitment & Compatibility

Cut for the airbox of the CFMOTO NK 675 as built in 2025 and 2026. Three CFMOTO 675 models share this housing and this code; the 450-class NK takes a different element. The full list is in the Fitment tab.