Just saw a couple of posts that mentioned doing a tank lift for better air flow into the pre-filter portion of the intake. I'm rather curious about this since I'm gathering my parts for my cam and exhaust mods this spring. If it's worth it, I'd rather do this mod while I have the bike apart. I'm curious how this is done and also if there is any noticeable improvement in performance. I'd imagine that there would be a little more noise though.
A few years ago I removed most of the lip on the cast frame near the air filter on my 10' XR. I can't honestly say there was an improvement in airflow after I did it because I did a plethora of other mods at the same time. I'm not interested in doing any grinding on this bike.