Off the top of my head, that works out to about >50mpg. That sounds pretty lousy to me, normally getting about 70 mpg. But I haven't read about all you've done to the bike, but it obviously won't get what the 500s will.
However, the low and mid range of the carb is where you should be concentrating. The idle circuit, needle, float level has more effect on your mileage than the main jet unless you're really flogging it. But more importantly, you need to take care of any other problems that you may have, cams, ignition, etc, before you can get the carb right.
Bare