Air Filter Housings
About Air Filter Housings
The air filter housing, or airbox, holds the filter and keeps dust, water and engine heat out of the intake. Riders shop here for a replacement cover after a crash or a lost cover, to refresh a worn airbox on an off-road bike, or to fit an open air cleaner or intake system on a Harley-Davidson.
Listings include airbox covers for off-road models such as Honda CRF, Yamaha YZ and KTM, air cleaner kits and intake systems for Harley-Davidson, and OE-replacement high-flow air filters for Honda, Yamaha, Triumph and Ducati. An airbox cover has to seal against the box or water and dust can reach the filter, so match it to your year and model. A Harley air cleaner kit replaces the stock cleaner and changes airflow, so read the listing for fuel-injected or carbureted fit and plan on tuning if the maker says it is needed.
Brands here include K & N, S&S Cycle, Arlen Ness, Acerbis and Trask. Pick your bike in the Ride Finder at the top of the page. For filters see Air Filters, and for ducts and covers see Intake Covers, Ducts & Scoops, all in Air Intake & Fuel Delivery.
FAQs on air filter housings and airbox covers
Why does an airbox cover matter on an off-road bike?
The cover seals the airbox so dust, mud and water cannot reach the filter and engine. A cracked, missing or poorly fitted cover lets unfiltered air in, which can wear the engine. Replace a damaged cover and check that it seals all the way around.
What should I check after installing an air cleaner kit?
Check that the filter and backing plate are tight, the gaskets are seated, the throttle moves freely and any breather hoses are connected. Then check whether the bike needs a tune, as a different airflow can change the fuel mixture.
Do I need a new filter when I change the air filter housing?
That depends on the listing. Some kits include a filter and some housings use your existing one, so read the listing to see what is included, and use a filter that matches the housing. Replace a worn or damaged filter whenever you open the airbox.
Can I ride without the airbox cover?
No. Running without the airbox cover lets unfiltered air, water and dirt reach the filter and intake, which can damage the engine, and a soaked filter can choke it. If your cover is cracked or lost, replace it before you ride.
Does an intake system need a tune on a fuel-injected Harley?
Often it does. A different air cleaner changes how much air the engine gets, and the fuel map may need to match. Follow the maker's instructions for your model, and have a tune done by a shop if they say it is needed.
