2000 Yamaha YFM400FWA(M) Factory Service workshop Manual, Page 83Get this manual
AIR FILTER CLEANING 6.Clean: Air filter element
INSP ADJ
Cleaning steps: Wash the element gently, but thoroughly in solvent
WARNING
Use cleaning solvent which is designed to clean parts onlyNever use gasoline or low flash point solvents as they may cause fire or explosion Squeeze