hello i just ordered a pro circuit r304 shorty for my 2001 kx 100...in the picture it says factory sound on the pipe...does this mean its not going to sound different?? Is it going to sound stock...please respond if u know...thanks
Don't sweat it.. That is normal. Factory does not mean stock, it means Factory Race, like "what the pro's use". That is normal for pro circut products. Like FMF, it stands for Flying Machine Factory. It's going to be loud.
As for performance, the shortys were designed to increase the low-end area. Since your 100 has little performance down low, you are going to gain some power there. Enjoy your pipe, and silencer.
But remember, most tracks and riding areas (about 95%) were closed down due to noise complaints. Though alot of it was because the new 4-strokes uncorked.