I have a 1993 Stratos parked in my garage. Been out of town for a month and upon my return had a strong gas odor in the house. I have noticed this smell slightly in the past, but have ingonred it until now. I can't look at the tanks because they are under the seats. Has anyone had this problem? I've not found any sign of gas leaking. Could it be coming from the vents? Is there a way to shut these?