I have the same problem with my 2002. this was the first year the bike had beed stored and just prior to the winter the regulator started to mess up. will need to replace that. but over the weekend i had 110 miles for the first 3 bars then within 10 miles lost an additional 3 bars. I am hoping that replacing the reg/recf will solve this issue. along with replacing the plugs and servicing.
I consistently get @200 miles per tank. My 06 has @7200 miles and is stock. That is usually what I get while commuting to work, some rural some city riding. If I go for a day ride I usually can squeeze @220-250 mile from a tank. I ride mostly in the 4000-7000 rpm range. I don't like to keep the revs up alot, it gets on my nerves.
Have your emissions control system checked. Specifically check the Purge Control Valve (PCV) and the Air Control Valve (ACV) My Hawk GT had a similar problem... it was a California model, which meant it had all that smog control crap. I ripped it all off and plugged the holes, which helped bring my MPG back to normal. As I understand it, the emissions controls on the VFR are far more complicated, so you might want to fix the system rather than rip it out.