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

Some motorcycles are maintained by the person who rides them, and some are not. A machine shared inside a household, run in a small fleet or passed between riders is serviced against a calendar by somebody who never saw how it was used, and that difference bears on the choice of filter medium more than any figure on a data sheet does. The Sprint Filter P08 F1-85 is a racing element. It filters at 85 microns, coarser than the standard P08's 80, and returns 15,000 litres per square metre per second of airflow against 5,050. That specification quietly assumes somebody is opening the airbox often. An MX King in shared use is the machine least likely to get it.

Key Features

• Dry polyester built for racing: 85 microns, airflow 15,000 l/m²/sec
• A coarser barrier than the standard P08's 80 microns — flow gained, retention given up
• Washable and reusable, designed by Sprint Filter to last the life of the motorcycle
• Nothing is oiled, so there is no oiling procedure for a second person to get wrong
• Filtering area roughly twice that of other performance filters
• Replaces the original element in the standard airbox — no modification, no remap, homologation intact

A racing medium is an assumption about attention

Coarser filtration is defensible where the surroundings are controlled and the element is looked at between outings: a swept surface, a short running time before the next inspection, an engine that will be opened anyway. Shared use inverts every one of those conditions. The machine runs continuously, in whatever air the route provides, and the intake is opened when the schedule says so rather than when the riding suggests it. Nothing about the element fails there, which is what makes the mismatch easy to miss. It simply spends its whole life delivering the half of the trade that costs and none of the half that pays.

What to fit instead, and what holds either way

For a motorcycle that is inspected rarely and ridden by several people, the finer media err in the safe direction: the P14 at 14 microns and 1,800 l/m²/sec, or the standard P08 at 80 and 5,050 as the general-purpose balance point. The rest of the specification does not change with that choice. Every one of these media is dry and washable, and nothing has to be applied to an element before it goes back in. The same is true of PM186S F1-85 itself: a well-made part, two years of warranty from the date of purchase, aimed at a use this motorcycle does not have.

Care and cleaning

Compressed air, clean side outwards, is the ordinary service. Anything that survives comes off in lukewarm water with a mild detergent, rinsed until the water runs clear. The element then dries completely in open air, clear of heat and of flame, and goes back in dry. No oiling belongs anywhere in that sequence. Look in the Downloads tab for the maintenance sheet.

Fitment & Compatibility

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