When I removed the Mikuni BST for cleaning I noticed a rubber tube connected to a nipple located just above the gas inlet nipple and near the rear barrel of the carb. Hope to post a photo but the above description pretty much tell you where it is.....anyway, this rubber tube attached to the nipple in question went nowhere, the rubber tubing was about 4-5" long and just sort of pointed upward but attached to "nothing". Is this the way it's supposed to be or connected to something? Tnx in advance for ya'alls help.