Sprint Filter P08 F1-85 Air Filter for Racing – Suzuki GSX-R125 (2017–2026) PM250S F1-85

The GSX-R125 carries a superbike's name and bodywork, so the racing medium in the catalogue looks like the obvious upgrade. Worth being blunt, then, about what the money buys. The P08 F1-85 is by some distance the dearest of the three media offered for this airbox, and it returns more airflow and less filtration: 15,000 litres per square metre per second instead of 5,050, at 85 microns instead of the P08's 80. On a GSX-R125, whose output is fixed by the licence class the bike was drawn around, no part of the engine is waiting for that air.

Key Features

• Sprint Filter's racing weave in dry polyester: 85 µm filtration, 15,000 l/m²/sec
• Coarser than the P08 by five microns — three times the flow, bought with retention
• Free of filter oil, so nothing migrates on to the throttle body or sensors
• Sits in the standard airbox where the original sat; no remap involved
• Cleaned with compressed air rather than reordered; warranted two years from purchase
• Meant for racing; a standard GSX-R125 is better served by the P08 or the P14

Paying more for less filtration

Both halves of that heading are true, and neither is a criticism of the element: it is what a racing medium is. Sprint Filter's comparison gives the F1-85 95.22 per cent retention against 93.13 for the P08 — but those figures describe 100-micron particles, a size both weaves stop comfortably. The number that decides the everyday question is the aperture, and 85 microns is wider than 80: everything between the two passes here and did not pass before. What the premium buys is a specification written for engines rebuilt on a racing schedule, not for a learner-legal 125 running a year between services.

Who the F1-85 was drawn for

It belongs on machines where every other restriction has already gone — intake, exhaust, calibration, homologation — and where a builder accepts coarser air deliberately because the engine is apart often enough for it not to matter. A road-trim GSX-R125 is the opposite: its restrictions are the reason it can be ridden on an A1 licence at all. What it gains from is an intake resistance that stays where it started, which the P08 delivers with better filtration. On dusty roads the P14 at 14 microns and 1,800 l/m²/sec is the better trade again: finer holds more and flows less, always — and the flow given up here is not in use.

Care and cleaning

The PM250S F1-85 is serviced dry: compressed air applied to the clean face and pushed out through the medium, so the dirt leaves by the route it came in. A deeper clean uses lukewarm water with a mild detergent, rinsed until the water runs clear, after which the element dries completely in open air. Heat and flame damage the material, so neither is used; refit only once dry. The maintenance sheet sits in the Downloads tab.

Fitment & Compatibility

Made for the Suzuki GSX-R125, 2017 to 2026, replacing the original in the standard airbox without modification. The same part serves the other small-capacity Suzukis on this housing plus one machine from another marque, five in all; the full list is in the Fitment tab.