.....I have been dialing in my yzf450 for months. I finally got it super sweet. 8oz flywheel 47 rear WB Carbon Pro Exhaust Azonic Bars CR HIGH Pro Circuit Susp. The thing glides a round the track, and the power is super sweet--. .....But I can't get rid if it decel-back firing. I hear other guys around the track having a little bit of it, but mine does it a lot. It also acts like there's an air leak somewhere. When I am comming back into the pits, it idles high until I snap the throttle a little. .....My track buddie who I carpool to the races with, laughs at me. He rides a Honda 450 and just bags on my Yami. In good taste, he kindly mentions how his doesn't back fire or idle up. I gotta get this figured out. You know when you are super confident in your machine, you're that much faster. .....Thanks in advance guys, Any info or suggestions would be greatly appreciated. -Spode.