A lot of people recommend the Bubs, but I got a set of Specialty Spares slash cuts about a year ago, and I love 'em. They sound great, I got some noticeable improvement in power, and the jet kit was perfect. Pat Whitbeck's website has great instructions on re-jetting, and it was a snap to install. Plus, you can't beat the price, and you can remove the packing if you really need it loud, right?