The gas smell will be strongest on hot days, even on my newer vehicles I have noticed the gas venting on hot days. I have had my van out cruising this last weekend and when it was shut off and setting, I could smell a gas odor coming from the passenger side of the van. It has been 90 degrees here the last couple days. I replaced my charcoal canister 2 years ago, all the charcoal had turned to a fine sandy like substance. Part of my smell is I need the float replaced in the carb, when the van is hot and after setting for 20 minutes or more, when I start it up, I get a strong smell of gas, like when a carb is flooded. Otherwise the van runs so good, I hate messing with the carb. Guys tell me the old floats, which are original, have a pinhole in them.