A fuel filter is placed in the fuel line of most internal combustion engines which filters out dust and dust particles from the fuel, as unfiltered fuel may contain several contaminants from its prior storage tank along with dirt. If these dust particles are not removed before the fuel enters the injection system, they will cause rapid wear and tear due to their abrasive action. Besides, fuel filters also improve the performance of the bike engine. Fuel filters need to be periodically replaced or cleaned, or else it will cause a restriction in the fuel flow, resulting in a drop in the engine performance.
Some fuel filters, especially on diesel engines, are of a bowl-like design that collects water at the bottom, which can be drained out. Water collection is also indicated by a water sensor signal on the dashboard. Close to the diesel fuel filter, there may also be a fuel heater to avoid the formation of paraffin wax inside the filtrating element which would ultimately stop the fuel flow to the engine.