Sprint Filter P08 F1-85 Air Filter for Racing – CFMOTO NK 800 (2023–2026) PM273S F1-85

There is no racing class for the CFMOTO NK 800. No cup, no championship, no grid of them anywhere — and Sprint Filter catalogues a racing element for it regardless. That is not a contradiction and it is not a hint either. Media are listed against housings: once the tooling for this airbox exists, every medium in the range can be cut to that shape, and a price list records what can be supplied rather than what anyone asked for. Reading a listing as a recommendation is the mistake this page exists to prevent.

Key Features

• Dry polyester rated at 85 microns, with a flow figure of 15,000 l/m²/sec
• Measured at 95.22 % retention against 100-micron test particles
• Identical shape and fit to the standard element, straight into the series airbox with no remap
• Roughly double the filtering area of other performance elements
• Dry for its whole life, never oiled, regenerated with compressed air
• Built for the motorcycle's service life and warranted two years from purchase

The retention figure, read properly

Ninety-five point two two per cent against the standard weave's ninety-three point one three looks like a clean win for the wider mesh, and it is genuinely puzzling until you notice the test. Both figures come from a comparison using 100-micron particles, and 100 microns is larger than either opening — so the measurement says something about how a cloth behaves at the coarse end and nothing whatever about the fine fraction, which is where the five-micron difference in the mesh would actually show up. One test at one particle size does not rank two media across the range.

What would have to be true

The extra flow is only drawn on with the throttle wide and the engine near the top of its band, so the buyer who benefits is one whose machine spends real time there — a closed course, track days taken seriously, and an airbox opened on a race rhythm rather than a road one. Against that it costs a little over two and a half times what the standard element does and leaves five more microns open in every hour of ordinary use. And neither element adds power to a standard NK 800; nothing that drops into the series box does.

Care and cleaning

Blow it out with compressed air from the clean face outwards, and on track do it between sessions rather than between services. Film and residue come off in lukewarm water with a mild detergent, rinsed until the run-off is clear. It dries slowly in moving air and never with heat or a flame, and the PM273S F1-85 is refitted dry with nothing applied to it. The maintenance sheet is in the Downloads tab.

Fitment & Compatibility

Listed for the CFMOTO NK 800 of 2023 to 2026, one element per machine, and for no other model. The standard weave and the 14-micron mat for this airbox carry the same single-machine fitment.