Aftermarket GY6 Fuel TapAftermarket GY6 Fuel Tap A motorcycle fuel filter is a small, cylindrical component that filters impurities and debris from the fuel before it enters the engine. Typically made of durable materials like plastic or metal, the filter is designed to ensure the engine receives clean fuel, which helps improve performance, fuel efficiency, and prevent clogging of the carburetor or fuel injectors. 2 Outlets Screws On 15mm thread 21. 68mm Diameter On Nut.