Sprint Filter P08 F1-85 Air Filter for Racing – KTM 125 Duke (2017–2026) PM200S F1-85

One element code covers this whole family, 125 through 390, naked and faired, at one price to all of them. Fair enough for the part, but the sum works out differently on each machine, and on the 125 Duke it works out worst. The P08 F1-85 is Sprint Filter's racing weave, passing 15,000 litres per square metre per second where the standard P08 passes 5,050, and it asks roughly two and a half times what the P08 asks. The smallest engine on the list has the least use for what that buys.

Key Features

• Dry polyester racing weave: 85 microns of filtration at 15,000 l/m²/sec
• Five microns more open than the standard P08 — the flow is charged to retention
• Completely oil-free, so no film can travel forward onto the throttle body
• Takes the original element's place in an untouched airbox; mapping left alone
• Cleaned and refitted for the life of the motorcycle, two years of cover from purchase
• Specified for racing — on a road-ridden 125 Duke the standard P08 is the sounder buy

Cost is set by the medium, benefit by the engine

The two halves of this decision are settled by different things, and on a 125 they pull a long way apart. What the engine can do with extra air is fixed by its displacement and fixed again by the A1 category it was drawn around: the ceiling here is a licence class, not the diameter of anything in the intake. The P08 already supplies more than this engine asks for at any point on the rev counter, so multiplying the supply by three hands over a reserve with nobody to claim it. The wider cloth, by contrast, is never idle. Everything between 80 and 85 microns that the finer weave held back now goes through, on every ride.

What a replacement element honestly does

It will not make a standard 125 Duke quicker, and this page will not suggest otherwise. What genuinely changes is quieter than that: the resistance the engine works against starts lower than a disposable panel's, and because polyester is washed rather than written off, it can be put back to that figure at any service instead of drifting upward across a year. A part you throw away only ever moves one way between replacements; a part you clean moves back. That argument belongs to every element in this housing, and the P08 makes it while keeping five microns more of the fine dust out.

Care and cleaning

The PM200S F1-85 is serviced dry and barely leaves the bench. Compressed air is held to the clean face and driven outward, so the dust leaves by the side it came in. When air stops being enough, lukewarm water and a little mild detergent finish the job; rinse until the water leaves clear. Drying happens in open air and only there — no heater, no flame — and the element goes back in dry. Sprint Filter's maintenance sheet is filed in the Downloads tab.

Fitment & Compatibility

This is the P08 F1-85 for the KTM 125 Duke, 2017 to 2026, dropping into the standard airbox in place of the original. Thirteen machines share the code, KTM and Husqvarna together, so order by element code and year rather than by the name on the tank. The full list is in the Fitment tab.