We have 2 scags both with 25 Hp Kohler motors. The air filter is a Kohler 25 083 04 s inner air filter. The outer is 25 083 01 s for the 61 inch scag. The 52 inch mower air filter is a Kohler 2408303-5. Can I put another air filter on them and what do you recommend?? NAPA, fram? ANy others could you please let me know the Kohlers are really expensive. Thanks so much!! Donny Son and Father lawn service..