Sprint Filter P08 F1-85 Air Filter for Racing – Yamaha Exciter (2015–2026) PM186S F1-85

A filtration rating is easy to picture wrongly. Eighty-five microns sounds like an opening eighty-five microns across: everything larger stopped, everything smaller waved through. A woven fabric does not work that way. The P08 F1-85 is spun from polyester thread and used dry, and a particle is caught by touching a fibre at least as often as by failing to fit between them. That is worth understanding before buying the racing medium for an Exciter, because it explains what the move from 80 microns to 85 really is: a more open weave, holding back less and passing 15,000 l/m²/sec against the P08's 5,050.

Key Features

• Woven polyester racing medium, dry at every stage — no oil at all
• 85 microns of filtration; airflow 15,000 litres per square metre per second
• More open than the standard P08 at 80 microns: retention pays for the flow
• Filtering surface about twice that of other performance filters
• Straight into the standard airbox — nothing modified, no remap
• Washable and reusable, with a two-year warranty from purchase

A rating is a statistic, not a doorway

The P08 family is woven from polyester threads of 22 microns and upwards, a diameter often mistaken for the size of the openings, which it is not. A woven medium presents a population of gaps and a forest of fibres, and it captures three ways at once: a particle too large to pass, a small one that follows the air but brushes a thread on the way, and a heavier one whose momentum will not let it turn with the air, so it lands. A rating marks where that combined capture rate falls away; it is not a dimension anyone could check with a gauge. Five microns of difference is not a wall moved five microns but a probability curve shifted in one direction.

Where the extra airflow comes from

From the same geometry, read the other way round: a more open structure puts less fibre in the path of the air, so it passes more air and holds back less of what the air carries. No third quantity is being improved. Whether the Exciter has any use for the result is the remaining question, and for a standard 150 cc single the answer is no: the peak this engine can draw sits well below what the original housing delivers, so the surplus is spent on nothing while the coarser weave works continuously. Bought for competition, PM186S F1-85 is a considered choice; for road use the P08 at 80 microns, or the P14 at 14 microns where dust governs, is the better purchase.

Care and cleaning

The normal service is compressed air, clean side first, worked outwards. Where that is not enough, lukewarm water with a mild detergent will do it, rinsed until the water runs clear. Leave it in open air until it is dry through — heat and flame both excluded — then refit it dry. Nothing goes on afterwards: the polyester has never been oiled. The maintenance sheet sits in the Downloads tab.

Fitment & Compatibility

Made for the Yamaha Exciter, 2015 to 2026, and a direct replacement in the standard airbox. The same element is listed for six model names across that period; the list is in the Fitment tab.