Sprint Filter P08 F1-85 Air Filter for Racing – Honda MSX125 (2013–2019) PM180S F1-85

Almost every account of an intake part on a small bike describes the same thing: it feels crisper afterwards. It very often does — and on a machine like this the reason is rarely the specification of the cloth. An element is usually changed when the old one has been in the airbox for years, so the comparison being made is not between two materials but between a clean filter and a dirty one. Add a different day, a different air temperature and a fresh tank of fuel, and the impression has three explanations before the weave gets a turn. PM180S F1-85 deserves to be judged on what can actually be read.

Key Features

• P08 F1-85 racing weave: 85 µm filtration at a rated 15,000 l/m²/sec
• Dry polyester, never oiled, so no film can be drawn along the intake tract
• Deep pleating fits considerably more cloth into the standard airbox
• Fits the original MSX125 housing as it is — no cutting, no adapter, no remap
• Washed and refitted instead of consumed at service intervals
• Built for the life of the machine; two years of guarantee from purchase

What can be read and what cannot

What can be read is the specification. This cloth is rated at 85 µm and 15,000 l/m²/sec; the standard element for the same housing is 80 µm and 5,050. That is a coarser weave passing about three times as much air, one exchange in two directions, and it is true whatever anybody feels on the ride home. What cannot be read on a 125 is the difference at the throttle: there is no instrument on the bike to report it, and what would show up is smaller than the day-to-day variation of the machine itself. Deciding from the numbers before fitting is the only method that does not flatter the purchase.

The one context that changes the answer

Where the extra flow is genuinely drawn on — a machine used competitively, opened and inspected on a schedule counted in running hours — the coarser aperture is a supervised choice and the exchange is deliberate. Where the bike is ridden on the road and serviced by mileage, the same aperture is simply in force for the life of the element, with no occasion to draw on what it bought. For that use the standard PM180S is the better answer, and where the roads are dusty the finer PM180P14 sits at the far end of the same trade. Nothing fitted inside a standard airbox makes a standard MSX125 stronger.

Care and cleaning

Compressed air is applied to the clean side of PM180S F1-85 and pushed outward, so deposits leave by the face that collected them. When air is not enough, wash it in hand-warm water with a mild detergent and rinse until clear. Dry it in still air only — no hairdryer, no exhaust, no flame — and refit it dry, with nothing applied to the cloth. Sprint Filter’s maintenance sheet is in the Downloads tab.

Fitment & Compatibility

PM180S F1-85 is listed for the Honda MSX125 from 2013 to 2019 and for the Grom from 2014 to 2019 — two names, one housing, one reference. The machines built from 2021 onward take a different part, so read the build year rather than the model name and check it against the compatibility list before ordering.