what are yours experience with emptying out the air box?? me and a friend run both ours empty and it seems to gain a little bit, have read that it can cause problems...?
usually what happens is it becomes alot more sensative to temp changes and requires constant attention to jetting with gutted airbox's, not to mention they sound like a loud howling noise. Anytime you enable a engine to get more air, it makes more power as all a engine is, is a airpump. Have had good results with leaving the shelf in the airbox and drilling some 1-1.25" holes in the top plate under the foam, try to offset the holes from the shelf holes so it doesnt mess up the signals inside the airbox, yamaha spends alot of time in thier airbox design for the frequencies the carbs recieve. No jetting problems this way and it gets more air also.