If your bike is starting to misfire or lose power and gas mileage, it might be time to check your air filter to see if it's time for a replacement. Dirty and bad air filters can cause severe engine problems and cause trouble in various parts of your bike, which is why we suggest replacing your old or missing filter with this High-Performance Air Cleaner Kit from HardDrive! These custom air cleaners are great at keeping your engine running smoothly and adding style to your bike, allowing the use of any 5.5" round air cleaner cover with a center bolt.