I just finished a full maintenance run on my bike, including valves, carbs, plugs, brakes, etc..

On the front of the bike there is a small black plastic unit that the hoses that hook to the front faring go into; it then sends a hose out to the air vent control selenoid valve that is hooked up with a rubber grommet to the front of the bike (under the gas 10mm gas tank bolts).

Best I can tell from the manual the unit is called a sub-air cleaner.

Question: One of the inlets to this "sub-air cleaner" has nothing on it; its missing a hose. Again best I can tell from the manual it's for California type bikes only. If this is the case, shouldn't there be something covering the hole? or is it OK to be left open like that?

Cheers!