A motorcycle's engine needs a steady supply of air to keep working efficiently. Air filters help keep contaminants out of the air supply and the engine running smoothly. When air filters become clogged, however, engine performance can be affected. Regular maintenance is the key to avoiding problems resulting from clogged filters.
Air filter function
Air filters sit across the engine's air intake port, screening out dust, dirt and other hazardous substances. If particles of dust or sand enter the air intake, they can restrict airflow as well as harming the engine in other ways. If abrasive particles get into the engine, they can cause damage to engine parts, reduce the effectiveness of lubricants and prevent the carburettor from functioning properly. Air filters trap these particles in a paper, plastic mesh or foam screen, preventing them entering the intake.
Clogged air filter
A functioning air intake helps to insure a steady supply of air into the engine. However, contaminants build up on the filter over time. If they aren't removed and the filter is not replaced, they will eventually block enough of the filter's apertures that the filter itself begins preventing the engine from getting the air it needs. When this happens, a number of engine problems can result, ranging from poor performance to complete engine failure.
Typical engine problems
In order to function optimally, an engine requires the correct mixture of fuel and air. If not enough air reaches the engine, it will not have all the oxygen it needs for the fuel to combust. When this happens, fuel efficiency and engine power can both decrease; some of the fuel reaching the engine is not being turned into power. Incompletely-combusted fuel can also lead to black smoke coming from the motorcycle's exhaust. This is a common symptom of a clogged air filter.
Motorcyclists should regularly clean their air filters. An older filter may have to be replaced. Manufacturers will specify how regularly filters ought to be replaced, but clogging can vary depending on air conditions. Riders who spend a lot of time in dusty off-road environments, for instance, should clean their filters frequently. Checking air filters before embarking on any long ride is advisable; the process doesn't take long but can make a big difference to the motorcycle's performance.