We do have this sprocket available for your 2004 GS500f. This particular sprocket for your model is only available in 16 teeth which is the same as your stock sprocket. If you are trying to make gearing changes we can definitely help with that. A larger front sprocket with more teeth will give you better top speed and a smaller front sprocket with less teeth will give you better acceleration. If you can give us a call and let us know what you prefer, we can get you taken care of with the gearing to suit your needs.