To avoid fire or explosion risk not to use gasoline or inflammable solvents to clean the filter sponge. Wash carefully the filter sponge with an appropriate clean solvent, not inflammable or with a high volatility point, and clean it with compressed air.
 Dry carefully the filter sponge. Apply on the whole filter sponge surface Malossi oil for filters 7.1 Racing filter oil Full Synt.
Squeeze the filter sponge carefully to eliminate excessive oil; the filter has to be completely impregnated but not dripping wet.
 Reassemble the filter sponge as originally fitted to your vehicle.