You should change the air filter on your motorcycle for every mile (kilometers) of distance traveled.
For cotton gauze and froth air filters, the same frequency can be used to take out the filter, clean, and re-oil them.
Another good replacement frequency is to change the air filter for every alternate servicing of your motorcycle.
Also, you should get your air filter checked every time you take your motorcycle for servicing. However, you can replace or clean the filter consequently, if the filter is congested early.
Sando Auto Traders provide the best air filters for all vehicles. Your AutoTrader's nearest to Vedarnayam/Ayakkaranpulam.