Get a 28mm clamp on airfilter from Amazon. If you wanna keep the bike stock then youll need an air box like the other guys are saying. Changing the airfilter may require you to change the jetting as well
No I have this https://www.amazon.com/gp/product/B000VJSQ2O/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 aftermarket filter on it.