Sprint Filter P08 Air Filter for Road & Track – Honda CTX700N (2014–2017) PM181S

The CTX700N is built around an engine that finishes its work early. Long stroke, modest compression, a rev ceiling closer to a small car's than to a sportbike's — it is a torque engine, and a torque engine spends nearly all of its life at part throttle in the middle of the range. That is worth knowing before choosing an air filter, because the peak-power claims printed on most filter boxes describe a condition this motorcycle is never in. Nothing in a box makes a 670 cc commuter twin meaningfully faster. What the Sprint Filter P08 PM181S offers is a low intake restriction that stays low between services, instead of one that climbs quietly as a paper element loads.

Key Features

• Nothing is applied to the polyester — it filters dry, so no oil can travel on to a sensor or a throttle body
• The area doing the filtering is roughly double that of other performance elements
• Polyester thread of ø 22 microns and up, woven to a calibrated aperture rather than pressed from pulp
• It replaces the standard element where it sits: no modification, no remap, no change to homologation
• Compressed air is the normal service, after which the same element goes back in
• Two years of warranty from the date of purchase

What restriction costs an engine that never revs

A high-revving four is sensitive to intake restriction at the top, where it is breathing hardest. A low-revving twin never goes there, so the effect shows up somewhere else: in the first fraction of throttle opening, and in how promptly the engine picks up from a closed throttle in traffic. Those are transient events, and a filter that has loaded up over a season blunts them before it does anything measurable to peak output. Keeping the medium clean is therefore not a power question here. It is a manners question, and it is the one the rider feels.

The interval, not the part, is the variable

Every paper element is at its best on the day it is fitted and worse every day after. The curve is not steep, which is exactly why it goes unnoticed until the element is changed and the bike feels different for a week. A woven polyester element is serviced back to its own baseline instead of drifting away from it: blown through with compressed air, washed when a hard season has earned it, refitted the same afternoon. Sprint Filter designs the P08 to last the life of the motorcycle, so the CTX700N gets its baseline back rather than a new consumable.

Care and cleaning

Refit it dry — that is the step people get wrong, and it matters because nothing here is oiled. Before that: compressed air from the clean side, worked outwards, or lukewarm water with a mild detergent when the element has earned it, rinsed until the water runs clear. Let it dry in open air alone, never with heat, never with a flame. The Sprint Filter maintenance sheet is in the Downloads tab.

Fitment & Compatibility

Made for the Honda CTX700N from 2014 to 2017. The same PM181S element covers five machines built on the same parallel-twin platform; the complete list is in the Fitment tab.