I have a 2005 yz 450. At first I was a little shy about buying such a big bike.I am 42 and My previous bike was 15 years ago and was a yz 250. After now about 10 or so rides getting used to the bigger bike. Im actually wondering if I need more horsepower. My friend says im just imagining things. But I think I might need more power. Somebody told me the benefit of having a new pipe is that I can go into the corners in a higher gear cause I have more torque and therefore gain time. I mostly ride motocross tracks and about 40% sand motocross tracks. Im shure some of what I am feeling is being on the sand is robbing power. But im not clearing some of the jumps I would like to clear. Im just missing that rocket power of the 2 stroke. I also weigh 250 lbs. I might start racing old timers classes. Any thoughts ?? Gearing change ? Race fuel ? A aftermarket pipe ?