Whether you choose Original or BIO formula for your filter maintenance, the cleaning and oiling of your air filters follow the same steps:
DO use an oil that is formulated specifically for foam filters. Gear oil is not the same!
DO allow the filter to properly dry after washing. Oiling the filter without allowing it to dry sufficiently will trap some of the moisture.
DO pre-oil the filter at least 24 hrs before riding to allow the oil to evenly penetrate the pores and allow the thinning agent to evaporate. A recently-oiled filter will cause rich conditions.
DON'T use gasoline to clean a foam filter. It will harden the glue seams and dramatically shorten the life of the filter.
DON'T wring out the filter when oiling. It is best to massage the oil through the pores with your hands. You can gently fold the filter and squeeze out the excess oil.
DON'T use compressed air or a hair dryer to speed up the filter's drying time(s).