Ok, I just posted to share my experience, and it got transferred to the Exhaust tech section. Now, since it has gotten to be a tech post...here's my story. I bought the bike 2 years ago second hand. THe prior owner bought and installed the D & D's. He also installed D & D's supplied matched jets. I have not taken the time to see what jets are installed. It does seem to run a bit rich, but it runs good. The only thing I did when I got it was open the mixture screws out from 3 to 3.5 turns so it wouldn't backfire...and it doesn't anymore. Is the "lightshow a bad thing? I get about 40-50 mpg