Sounds just like my wife´s 96´ A.C.E., the guy who owned it first drilled out the baffles to make it louder and it ended up with a flat spot as did my firends 97´ A.C.E. when we put some V&H pipes on both bikes. What we did was install a Dial-Jet kit on both bikes and it got rid of the flat spots and seemed to give the bikes more power, pretty easy to install.