When I converted to a K&N mounted directly on the carb I connected the clear 1/2" diaphragm vent tube to a breather filter. It seemed to work fine, but I am noticing a little bit of sand making it's way into the area below the diaphragm in the slide chamber.

My question, can I plug off this line? What purpose does it serve? The slide seems to move up and down with the same amount of resistance with it plugged as it does with it open. Any help would be greatly appreciated.