Sprint Filter P08 Air Filter for Road & Track – Honda ST125 Dax (2023–2026) SM288S

Count the decisions an ST125 Dax owner ever gets to make. There is no fairing to specify, no coolant to change, no clutch lever to adjust, no riding mode to pick. Honda hung this machine on a folded steel spine and left almost nothing on it that could be chosen twice. What survives that subtraction is a very short list of parts the owner has any say over at all — and the element sitting in the airbox is one of them.

Key Features

• A single dry layer of woven polyester, rated 80 µm at 5,050 l/m²/sec
• Around double the working area of a typical performance element
• Holds back 93.13 % of 100-micron particles; four-layer oiled cotton manages 76.42 %
• Goes into the series airbox where the paper panel was, and needs no remap
• Dry from the day it is made: nothing to dose, nothing to creep downstream
• Cleaned with an air line and put back, year after year; two years' warranty from purchase

One of the few parts you choose

On most motorcycles the air filter is not a decision at all, it is a line in the service schedule: a figure gets quoted, a panel goes in, the same thing happens again a year or two later. A dry polyester element lifts that line out of the repeating column. It is specified once and then belongs to the machine, the way the seat or the silencer does. On a Dax, where Honda has already made nearly every other choice on your behalf and made most of them permanent, that is a rare thing to be able to do — and it is done without altering one dimension of the intake path.

What it will not do

Nobody should offer you this as extra power. A road machine in standard tune gains none from an element dropped into its own airbox, and a 125 runs into the ceiling of the class it is registered in long before the intake has any say in the matter. What the SM288S changes is duller and lasts longer: the restriction starts lower, and since the element can be taken back to the condition it arrived in, it does not travel in one direction only. Paper has a single curve. This one gets reset with an air line.

Care and cleaning

Compressed air does almost every service: hold it to the clean face and drive the load back out the side it came in. When something greasy will not let go dry, lukewarm water and a small amount of mild washing-up liquid will lift it, then rinse until the water is clear. Drying happens in open air and takes as long as it takes — no radiator, no heat gun, no flame, because heat is what wrecks polyester. The SM288S goes back in dry and bare. Sprint Filter's maintenance sheet is in the Downloads tab.

Fitment & Compatibility

Cut for the airbox of the Honda ST125 Dax, model years 2023 to 2026. One machine is covered and no other: Sprint Filter catalogues by housing rather than by engine family, so Honda's remaining small singles carry part numbers of their own — sharing a motor with them is not the same as sharing an element. The Fitment tab lists the coverage.