Sprint Filter P08 F1-85 Air Filter for Racing – Kawasaki Z900RS (2018–2026) PM166SF1-85

Standard panels are priced by the panel — a large airbox costs a little more to fill than a small one, and the catalogue reflects that. The racing cloth ignores it: the F1-85 carries the same price on almost every airbox listed, which on the Z900RS works out at a little over twice what the P08 for the same opening costs. A price that takes no notice of the motorcycle tells you what kind of part this is. Not the top rung of a ladder of filters for your bike, but one specification sold as itself — and the PM166SF1-85 should be bought on that basis or not at all.

Key Features

• Dry woven polyester in the F1-85 racing specification — never oiled, at any point
• 85 microns of filtration at 15,000 l/m²/sec, the highest flow figure in the range
• Measured retention of 95.22 % of 100-micron particles, against 93.13 % for the P08
• About twice the filtering surface of other performance elements
• Seats in the unmodified series airbox; nothing cut, nothing remapped
• Regenerated with compressed air; two years of warranty from the date of purchase

What a flat price says about a part

Parts priced by their specification rather than by their application tend to be parts made for a narrow job. The published numbers point in different directions and both are true: the weave opens from 80 to 85 microns while measured retention of 100-micron particles rises from 93.13 to 95.22 per cent, and flow goes from 5,050 to 15,000 l/m²/sec. Together they describe a cloth arranged to surrender as little as possible to the air passing through it. That arrangement earns its keep where an engine is asked, repeatedly, for everything the box can pass.

The Z900RS is not usually that motorcycle

The RS is bought for how it looks and sounds on a road, and ridden accordingly: long routes, moderate throttle, the engine rarely held at the top for long. Under that use the extra flow is capacity never drawn on, and the finer P08 weave is the better half of the same trade. No drop-in panel makes a series Z900RS noticeably faster either, this one included. Where the racing cloth does earn its place is an RS that genuinely sees track days — not for a lap time, but because it can be blown clean between sessions and comes back the same.

Care and cleaning

Servicing is dry work. Compressed air against the clean face, directed outwards, is a full clean in normal use. After a wet meeting or a salted road, lukewarm water with a little mild detergent finishes the job; rinse until the water runs clear, then let the element dry completely in moving air. Never use a heat gun, an oven or a flame — heat ruins polyester. It goes back in dry, with nothing applied. The maintenance sheet sits under the Downloads tab.

Fitment & Compatibility

Listed for the Kawasaki Z900RS from 2018 to 2026 and for that machine alone — one entry, shown under the Fitment tab. The same airbox is also served by the standard P08, the cheaper setting of the same trade and, for a road-ridden RS, the more sensible one.