The power normally just drops off after about 8500 rpms, but it shouldn't sputter. My 97 M900 pulled cleanly past 9000. For full throttle high rpm running, the only thing you can do is modify the jetting.Lastly, my 95 m-900 seems to sputter in high end revving, I would assume it should have more in the top end. i am used to 4-cylinder 4 valve water cooled Yamas. I love the torque on this, just wondering if I need some carb adjustment. low end torque is great.