The hose from the back of the stock air box went to a little electronic solenoid valve that hangs under the tank over the front jug. If you look at the chrome cover on top of the front jug you should see a rubber hose coming out at the very front edge. This hose goes back up to the same solenoid valve. This valve has 3 hoses attached to it (one from the stock air box, one to the rear jug and one to the front jug). There are some folks who have taken all these hoses off when "marbling". Marbling is just disconnecting this valve from the jugs. If you take the hoses off, you need to put rubber vacuum caps over all the places where the hoses were attached, especially the ones on the jugs. Otherwise water & dirt can get in there. The idea of removing all the hoses just cleans up the look of the engine a bit. You can not disconnect the valve from the wiring harness and remove it all together. If you do, the computer puts us a warning light for the fuel injectors.
'07 VN900 Classic
Horsepower is an illusion.
Torque is the source of all good things.