Why am I getting 30 miles/gal?!!!  

It seems that im running through a larger amount of fuel than normal, and I can't find or smell any leaks from the tank, carb, lines or petthingy.  Every time I hit the station I fill the tank up with roughly 2.1 gal of fuel, and after 50-60 miles or so, have to switch to the reserve.  This is a recent problem, a few months ago it didnt seem like this was happening.  A few thoughts...  

Is my idle too high?  Would carring a passenger for more than 50% of my riding time have that much of an impact?  Im basically at sea level, so im getting oxygen into the carb...not quite sure what I am jetted at, or have messed with the air/fuel mixture screw.  And like I said, I dont smell gas at all, or have any pooling underneath my parking space.  Im using 87, but before I was using a higher octane and getting more bang for the buck...but could that affect my mileage so much?

switch back to better fuel and compare, that would certainly be of great interest. packing double should affect the performance and fuel useage some, but not from the stock 50mpg to 30mpg. is the air filter clean and dry? i've had the air box fill with oil/fuel then soak the filter, and the stock paper wont flow through moisture. also check your motor oil, and make sure your carb isn't flooding into the crankcase, btdt. D@MN i hate that cv carb.