Get your hands on these spectacular beauties. These will fit the OKO/PWK/KEIHIN style carbs with the 48mm/2" opening. This is the same fitler polini uses on their big evo motors making 28hp. Ditch that $15 ebay filter.
These WILL NOT fit stock size carbs
this is for 21-30mm oko/pwk, polini, or keihin carbs.