If you've had your air box loose (assuming you still have one), check the 2 6mm hex head bolts that go through from under the rear fender. Those are not the easiest bolts to get in or out, and they also have a sleeve, or bushing, that fits between the fender and air box.
When I rejetted recently I noticed that my local shop tech had replaced the stock bolts and bushings with phillips head screws that had a washer-like head. I had no choice but to put them, back in, as I no longer had the stock fasteners. Now they're gone. (fell out?) It sure felt like they were seated and torqued in....now I get to order the stock bolts and bushings and put them in myself this time. He must have done that when adjusting the valves and changeing my pilot jets a while back, and they held fine until I pulled them out, but they're gone now.
That would be #s 16 and 24 in this schematic on Bike Bandit.
Air Box 
