The top right of the Mooney annual inspection/100 hour says "1. Inspect fuel injection system, clean screens & injector nozzles (refer to Textron Lycoming O/H Manual, Section 8 or TCM Service Manual."   So with a wrench remove the fuel hose     And a socket     To clean the screen you tap it on the table and stuff comes out.   and you keep tapping it and more stuff comes out       It kind of looks like so