OK, so I'm trouble shooting my 1986 VT700C. I realized the other day that the breather tube (skinny black tube in rear of tank next to the larger red one) coming from my gas tank was leaking gas. When I tipped the tank to the left so the gas level was below the tube it dried up, then when I returned the tank to level it leaked again. I emptied the tank and removed it and that breather tube was totally full of fuel. What could be causing this? Any suggestions moving forward? Thanks in advance!