Filters - General
Traditional scooters have only three filters which filter the air and fuel going into the cylinder. It is very important to keep the mixture in the cylinder clean. Rust from an old tank or the collection of dirt and dust can add wear and tear to a perfectly good engine.
The fuel line has a small gauze filter at the fuel tap and another, made of cylindrical mesh, in the carburetor. On a Vespa, the air is filtered inside the carb box or frame. On a Lambretta, air is filtered inside a filter box.
Two strokes do not have oil filters as they have no oil pump. The oil simply gets used and dirty and should be replaced every 3000 miles. For oil change info and instructions see either the Vespa or Lambretta oil change pages.