2000 WR400 and im looking for a good muffler upgrade. Now since it is a pretty nice bike i would kinda rather have new. Every where i look it seems everyone points to a used YZ muffler. What mufflers are as good or better then the YZ that i can buy new? I want more power! I dont care about noise i enjoy the nice sound of a healthy engine. Don't worry Im in farm country. No one cares about noise here. Most the ATVs around here completely drown the sound of my bike out easily.