Sprint Filter P08 Air Filter for Road & Track – Kawasaki ZX-25R (2020–2026) PM164S

Four cylinders inside 250 cc is a decision about revs. The ZX-25R makes its case a long way up the tachometer, in a region a twin of the same size never visits, and everything about the engine follows from that: short strokes, light reciprocating parts, and an appetite for air that arrives in rapid, closely spaced pulses. An engine that spends its best moments breathing that hard is the clearest case there is for keeping the intake path free — not because a filter adds anything, but because a loaded one takes something away precisely where this engine has the most to lose. The Sprint Filter P08 PM164S is the standard-airbox element for it.

Key Features

• Dry polyester that is never oiled — no film for the throttle bodies or the intake sensors to collect
• Fits the standard airbox as a direct replacement: no modification, no remap, no change to homologation
• The filtering surface is roughly double what other performance filters offer
• Threads from ø 22 microns, woven to a calibrated aperture instead of pressed from pulp
• Washable and reusable — compressed air is the routine service
• A two-year warranty, running from the date of purchase

Restriction is felt at the top, and this engine lives there

Intake restriction scales with how much air is moving through it. At small throttle openings and modest revs, almost any element in almost any condition will do. The picture changes as the engine approaches the part of its range the ZX-25R was designed around, where airflow demand is at its highest and a partially blocked medium finally costs something measurable.

Woven, not pressed

The P08 medium is a polyester weave built from threads from ø 22 microns, with an aperture that is calibrated rather than left to chance. Pressed pulp is a mat of random fibres; it filters well and it blocks steadily, and there is no way to return it to where it started. A weave can be cleaned back to its own condition instead. On a machine that is often ridden hard, kept for the sound and the revs, and serviced attentively, that difference is the whole point: the element is maintained alongside the engine rather than thrown away with the oil filter.

Care and cleaning

Compressed air, from the clean side and directed outwards, is all a routine service needs. When the element has earned more than that, lukewarm water and a mild detergent take it back to where it started: rinse until the water runs clear, then air-dry it completely — never with heat, never anywhere near a flame. Refit it dry. Nothing is oiled before, during or after, and never has been. The Sprint Filter maintenance sheet is in the Downloads tab.

Fitment & Compatibility

Made for the Kawasaki ZX-25R, 2020 to 2026. The same PM164S element serves eleven machines built around this airbox; the complete list is in the Fitment tab.