Sprint Filter P08 F1-85 Air Filter for Racing – KTM 250 Duke (2024–2026) PM293S F1-85

Set the two woven media of this family side by side and the arithmetic comes out lopsided. Filtration moves from 80 microns to 85, a few per cent of opening. Flow moves from 5,050 litres per square metre per second to 15,000, roughly threefold. One figure barely stirs; the other multiplies. The shape of that says who the racing weave was drawn for rather more clearly than its name does: someone whose engine can turn rate into work, and who is untroubled by the last few microns.

Key Features

• Dry polyester racing weave: 85 microns of filtration, 15,000 l/m²/sec of flow
• About a threefold rate against the standard cloth, for five microns of extra opening
• Retains 95.22 per cent of 100-micron particles, against 93.13 for the standard weave
• Never oiled, and nothing to reapply once it has been washed
• Sits in the untouched airbox where the paper panel was; no remap called for
• Two years of cover from purchase, on a part designed to outlast the service book

Two figures, two magnitudes

A specification that changes one number a little and another a lot is telling you which of them it was optimised around. It also warns against reading mesh width as the whole story: the published retention percentages put this weave slightly ahead of the standard one despite its wider opening, which is a reminder that a woven medium arrests particles by more than the size of its holes. Neither figure is a ranking. They describe two cloths built for different ends of the same range.

What follows for a road 250

A 250 Duke on public roads reaches the condition in which rate matters rarely and briefly, and pays for the specification the rest of the time in price rather than performance — the racing weave costs well over twice what the standard element does here. It buys no output in any case. No element dropped into a standard airbox adds power, and a single homologated within the A2 category is capped by the engine and its approval, not by the panel ahead of it. What the whole family offers instead is an intake restriction that begins low and returns there at every wash.

Care and cleaning

Dry service is the normal case: air at the clean face of the PM293S F1-85, worked steadily outward, until the weave gives nothing more up. Should something stickier have settled in it, tepid water with a mild detergent will release it, and the rinsing continues while anything is still coming away. From there it is open air and time — no heat of any description, and no flame anywhere near the cloth — with refitting held back until it is dry through. Sprint Filter's own sheet is in the Downloads tab.

Fitment & Compatibility

For the KTM 250 Duke built from 2024 to 2026, replacing the original element in the standard housing. Seven entries in the current KTM and Husqvarna single-cylinder range share this code, each with its years in the Fitment tab. The 250 Duke sold up to 2023 sits under the earlier Sprint Filter listing, which closes where this one begins.