i have a 1986 suzuki intruder ,, its pumping fuel while running throu the vent tube? now i do not see a check valve or a roll over valve on the vent tube.. is there suppose to be a check or roll over valve on the vent tube? and if not,, why would it be pumping fuel from the vent tube?.. it has not done this before,, and hasnt been running during the winter,, if that has anything to do with it or not?.. i just do not understand why it would be pumping fule out the vent,, its not over full.. or has been upside down,, the fuel is not areating(bubbling).. or foaming??? whats up with the vent tube?