Universal air filter Clamp-on K&N 57-1125P

Universal air filter (clamp-on) K&N 57-1125P mounts directly to the carburetor inlet, replacing the airbox and the original filter element. It is designed to improve your motorcycle’s performance.

Features of the K&N universal air filter (clamp-on)

There are four types of K&N universal air filters: straight round, tapered round, straight oval and tapered oval. The pleated design provides a larger airflow surface area.

For installation, match the outside diameter (OD) of your carburetor bellmouth to the inside diameter (ID) of the filter (given in inches and millimeters). All universal (clamp-on) air filters mount directly onto the carburetor bellmouth, replacing the airbox and the original filter element.

References starting with “RC” have chrome end caps; the others have black rubber end caps.

Warning: K&N clamp-on air filters are not road-approved.

K&N takes air filtration seriously

OE (original equipment) replacement air filters for cars typically add 1 to 4 hp. The secret of our success lies in the unique characteristics of our filter media, originally developed by K&N many years ago amid the dust, sweat and tears of desert motocross racing.

The high-flow cotton gauze air filter is washable, reusable and built to last the life of a car or motorcycle engine. It is made of four to six layers of cotton gauze sandwiched between two sheets of aluminum mesh. This media is then pleated and oiled to improve its filtration capacity and overall performance. K&N air filters were created for environments requiring maximum power and improved acceleration, as well as protection against dirt and dust from off-road racing.

The last air filter your engine will ever need

K&N warranties its filters for 10 years or one million kilometers. Why? Because the filters are built to last as long as your engine. Hand-built in the UK and the USA using the best materials, K&N original replacement air filters are washable and reusable.

We recommend cleaning and oiling your filter every 80,000 kilometers before reinstalling it in the engine—about once a year depending on how you ride. It will be like new!

To clean and re-oil it, buy our K&N Cleaner + Oil service kit and follow the easy instructions. You can also find all our tips for successful K&N air filter maintenance in our article “How to clean a K&N air filter”.