has anyone fitted a ingition advancer to a zx9r...98 model stock bike apart from 1 tooth down front sprocket,

 

raptor, not to a '98, but yes to a '95. I'm not knocking ZX9's (I love mine for what it is.) Putting an ignition advancer on a stock '98 may give you a tad more zip, BUT, remember, our bikes are 12-15 years old. It still won't wax your buddy's newer Gixxer.