on my a 15 i have a 32/36 webber. on the rocker cover i have a 2" air filter which you can buy from supercheap auto, robbos, repco and other aut parts shops. it does the trick for me. as for the one on the crank case i just blocked it off with a rubber door stop which you can get from bunnings warehouse. i hope this info is a help to some people.