Sprint Filter P08 F1-85 Air Filter for Racing – KTM 790 Duke (2022–2026) PM283S F1-85

Three Sprint Filter media are catalogued for this airbox. Two of them, the standard P08 and the finer P14, cover all three machines that share it: the KTM 790 Duke and the two Husqvarna 801 models. The third, PM283S F1-85, is listed against one machine only, the 790 Duke. Not because the Husqvarnas have a different housing — they do not. It is a listing decision, and a fitment list says what a manufacturer chose to catalogue, not which motorcycle deserves which cloth.

Key Features

• Racing-specification dry polyester weave, used without oil
• 85 microns of filtration; 15,000 litres per square metre per second of flow
• 95.22 per cent retention of 100-micron particles, measured by Sprint Filter
• Threads from ø 22 microns — the thread, not the gap between threads
• Fits the production airbox, no modification and no remapping
• Two years of warranty from the date of purchase

Eighty-five microns that hold back more than eighty

The F1-85 is the most open weave in the range and, in Sprint Filter's own comparison, the highest-retaining: 95.22 per cent of 100-micron particles against 93.13 per cent for the standard P08, with four-layer oiled cotton at 76.42 per cent in the same test. Both figures hold at once, because mesh width is only one of the terms that decide what a woven filter catches. What the cloth is unambiguously built for is flow: 15,000 litres per square metre per second against the P08's 5,050, roughly three times as much through a square metre of clean material. The mesh moves by five microns and the flow by a factor of three — a lopsidedness that says plainly who the weave was drawn for.

Whether a road-ridden 790 Duke should have it

Mostly no, and the reason is arithmetic rather than caution. The flow rate is only cashed in when the engine is asking for everything it can get and holding there long enough to matter, and on a naked middleweight on public roads those seconds are few. The mesh width, by contrast, is open every minute the engine runs. If the bike sees track days with any regularity, the case exists. Otherwise the standard P08 is the better specification. Either way, no element inside an unmodified airbox makes a standard 790 Duke noticeably faster; a dry medium offers a restriction that can be reset instead of replaced.

Care and cleaning

Compressed air through the element from the clean side, working outwards — an open weave gives up its load more completely than a fine one, which is part of what makes this specification workable between sessions. Water and a mild detergent when air is not enough, then rinse until clear. Dry in air only, never with heat or flame, and refit dry. Nothing is oiled. The maintenance sheet for PM283S F1-85 is in the Downloads tab.

Fitment & Compatibility

For the KTM 790 Duke built between 2022 and 2026, the only machine this code is catalogued against; the Fitment tab confirms it. The same airbox on the Husqvarna 801 models is served by the standard and dust media instead. A 790 Duke from the 2018–2020 run takes a different code, so check the build year.