K&N air filter kit RK-3931 Harley Davidson Dyna Models, Custom Assembly 08-09

THE RED AIR FILTER - THE ORIGINAL SINCE 1969.

There`s a reason top racers rely on K&N® to protect their trophy trucks in the Baja 1000, premium race cars in 24 Hours of Le Mans, million-dollar NASCAR engines and high-horsepower dragsters: K&N® air filters let air in and keep dirt out. Designed for the race track - built for your vehicle. Multi-layer, oiled cotton mesh ensures up to 50% more airflow than traditional paper air filters, which can increase horsepower. The durable filter frame and media are designed to last the life of your vehicle and are protected by a 10-year/million-mile warranty.

K&N Air Filter Inserts

Replacement air filters are simply swapped out for the stock air filter. No modifications to the system are necessary. The stock carburetor setup does not need to be changed in most cases. We do not recommend modifying the air filter box by drilling additional holes or omitting the box cover, as this will result in a leaner mixture and loss of power. Leave the filter box in its original condition and the new K&N filter will give you years of pleasure.