Sprint Filter P08 F1-85 Air Filter for Racing – Zontes ZT 350-X (2020–2026) SM277S F1-85

Work down the maintenance list of a motorcycle and one instinct holds all the way: the dearer version of a consumable protects better. A better oil, a better brake fluid, a better coolant, a better chain. The intake medium is the single line where that instinct stops working, and the ZT 350-X is as good a place as any to say so plainly.

Key Features

• Racing specification: dry polyester, 85 µm of filtration, 15,000 l/m²/sec of rated flow
• The most open of the three media catalogued for this airbox, and the highest flow figure of them
• Standard weave 80 µm at 5,050 l/m²/sec; nonwoven 14 µm at 1,800 — same housing, different ends of the trade
• Fits in place of the series paper panel with nothing cut, nothing adapted and no remap
• Roughly double the filtering area of an ordinary performance element
• Dry, never oiled, washed and reused for the life of the bike; two years of warranty from purchase

Where more money buys less mesh

The most expensive element offered for this housing is also the most open one. It filters at 85 µm where the standard cloth filters at 80, and the nonwoven in the same range is finer than either at 14. What the racing medium buys is capacity — 15,000 l/m²/sec against 5,050 — and capacity is the one property a road-registered 350 has no obvious way to spend. The shelf order that serves so well everywhere else in the service basket has to be put down at the airbox door, because here the ranking does not exist.

Choose by the air instead

Ask what this machine breathes rather than what the price list implies. Clean roads and ordinary use point to the standard P08. Gravel lanes, harvest season and long spells behind traffic point the other way, to the finer nonwoven that trades flow away at 1,800 l/m²/sec. Genuine competition, with intake demand held near the top of its range for long periods, points here. Three destinations, no ladder between them — and the dearest of the three answers a question a standard ZT 350-X never asks. None of them adds power to a production motorcycle.

Care and cleaning

Compressed air aimed at the clean face and pushed outward covers ordinary servicing, since what the material arrested leaves by the way it arrived. Oily rather than dusty loading calls for lukewarm water with a mild detergent, followed by rinsing until the water is clear. The element then dries in ambient moving air, well away from heat sources and flame, and the SM277S F1-85 is refitted dry with no treatment applied. Sprint Filter's maintenance sheet is available in the Downloads tab.

Fitment & Compatibility

Catalogued for the Zontes ZT 350-X of 2020 to 2026, alongside eight other Zontes machines in the 250, 310 and 350 classes. One element code covers all nine; check the code and then the build year.