If the smell is more like liquid gasoline fumes check the gas cap seal. On my 73' Spider the seal is cork. My gas cap cork had disintegrated and was allowing fumes to blow forward. You do need to keep a very small vent-hole in the center of the cork-cap seal though.
-Marty -- to be removed from alfa, see http://www.digest.net/bin/digest-subs.cgi or email "unsubscribe alfa" to [email protected]
