Sprint Filter P08 F1-85 Air Filter for Racing – Yamaha XSR 125 (2021–2026) PM198S F1-85

Almost everything bought for an XSR 125 can be seen. Bar-end mirrors, seat covers, exhausts, indicators — the appeal of the model is how it looks, and the aftermarket around it reflects that honestly enough. An air filter element is the opposite kind of purchase: it sits inside a sealed box under the seat, nobody will ever know it is there, and it therefore has to justify itself on merit alone. That is a useful test to apply to the P08 F1-85, because this is the racing medium, flowing 15,000 l/m²/sec at a filtration of 85 microns against the standard P08's 5,050 and 80.

Key Features

• Racing medium at 15,000 l/m²/sec — roughly three times what the standard P08 flows
• 85 microns of filtration; the wider aperture is what buys the air
• Dry polyester, unoiled, so nothing can travel onto the throttle body or the sensors
• Standard airbox, unchanged — no modification, no remap, and nothing on show
• Washable and reusable, cleaned with compressed air from the clean side
• Two years of warranty, and a service life meant to match the motorcycle's

Applying the test

On a standard XSR 125 the F1-85 fails it. The engine cannot use the extra flow, so the only thing that actually changes is the filtration, and it changes in the wrong direction. Nobody would choose to filter more coarsely for no gain if the decision were presented that way, and there is no reason to present it any other way. The standard P08 is the element for a road-ridden XSR 125; if it lives in a city or on dusty roads, the P14 at 14 microns is better still.

The version of this bike that passes it

An XSR 125 with a freer exhaust, an opened intake path and mapping to suit is a different machine from the one that left the dealer, and it is a common enough thing to build. There the extra air has somewhere to go and the F1-85 is the correct choice. What has not changed in either case is the airbox: this element replaces only the fabric inside it, leaving the box, its lid, its inlet and its mounting exactly as they were. A washable element stops being a consumable: it is blown through with compressed air at a service, washed when a hard season has earned it, and refitted the same afternoon. Sprint Filter designs it to last the life of the motorcycle, so after the first purchase the airbox stops appearing on the service bill at all — and that is true of the standard P08 and the P14 just as much as of this one.

Care and cleaning

Compressed air on the clean side of the PM198S F1-85, aimed outwards, then back in dry. For a deeper clean take lukewarm water and a mild detergent, rinse until the water runs clear and let it dry fully in air — never with heat and never with a flame. No oiling stage appears anywhere in its life. The Sprint Filter maintenance sheet sits in the Downloads tab.

Fitment & Compatibility

Made for the Yamaha XSR 125 from 2021 to 2026. The same PM198S F1-85 element covers seven machines across the 125 and 155 range; the complete list is in the Fitment tab.