Engine
What is an Air Filter?
A pleated paper or foam filter that stops dirt and grit reaching the engine's intake.
Simplified animation — not to scale.
In plain English
Every breath the engine takes passes through the air filter first, which traps dust, grit and insects before they can reach the delicate intake tract and cylinders.
A simple analogy
“The engine's equivalent of a face mask — letting air through freely while keeping the grit out.”
How it works
Air is pulled through the pleated filter element by engine vacuum on its way to the throttle bodies or carburettor. A clogged filter restricts airflow and richens the fuel mixture, while a torn one lets unfiltered grit straight through to the bore.
Signs of trouble
- ⚠Reduced power or sluggish throttle response
- ⚠Poor fuel economy
- ⚠Black, sooty smoke from the exhaust
- ⚠Visible dirt or oil saturation on inspection
Rough UK cost
£15–£70
Parts: £8–£45
Labour: £5–£25
Always get a written quote. Prices vary by bike, region, and parts brand.
Heads up: Motoautonomy is for general guidance only. If your bike is showing warning lights or behaving oddly, get it looked at by a qualified mechanic.