Thanks for the replies, my 07 is all stock except for the air screw and 22 cent mod. I took out 1 of the shims, so I guess it's now the 11 cent mod, to see if it helps. I'm really surprised I'm only getting 37mpg. I was expecting a lot better. My old DR 650 got 55 all the time with many more mods.
Can the lower run of your drive chain be lifted to just 'Touch' the rear tip of the rubber slider under the swingarm? If Not, loosen the adjusters until it Can! When one sets on a bike, the chain will 'tighten' due to swingarm arc.
Are your tire pressures set to 'at least 32 psi FRONT / 30 psi REAR?
Does your air box have any additional holes drilled into the top, aft of the battery, 4, 1" holes fit nicely between the left side and the right side. (Add air, instead of subtracting gas.)
I personally think that the second shim (11 cent mod) was 60 percent of your mileage problem.
I just rode 475 miles on Sunday, mpg's of 48-59, 1987 -A1. Yes, its not quite STOCK, but it is not FAR from it!