After reading a lot on VTX Cafe I decided to start experimenting with my drill. I figured this was something I could do myself, and I was unsatisfied with the Singer sewing machine sound. Started with 3 holes, ended up with 7 plus 2 deep ones. Must say this was very positive experience on the whole. I thought 5 outer(1/2") holes & 1 deep was probably the best it got for me. More holes seem to introduce some weird resonances that didn't sound good. I also started getting decel popping, gurgling, backfiring. I thought at this point I had gone too far to stop now... So I ordered Bub Jug Huggers, Glen's perm a/f tool and jumped in. I now have the world's loudest motorcycle with no decel probs, no gurgling, no backfiring. And so the saga continues.....