Quote Originally Posted by ZMC888 View Post
I've tried these mods on smaller bikes and really they make little difference except for the sound. ... IMHO, and I'm no expert but those baffles, spacers and the cat is in the muffler because it is a street bike to give you back-pressure to keep the torque which makes the bike more usable for a real world non-racing situation and obviously more environmentally friendly too. I for one wouldn't want an inline 600 on the road that was sluggish in the mid range torque band but was marginally more powerful around the red-line.
Here is it series of photos about replacing the exhaust system:
http://www.motorfans.com.cn/bbs/t_17344398.htm