So I was cruzing ebay on monday and came across a great deal on a Q2 for my '04 450. Also this week I was preping the same bike for a ride on saturday. now I have this rule that has developed over the years, it is a very simple rule but I still cannot stop myself from breaking from time to time, especially when I come home to find a cool new part sitting on my porch that I didn't ecpect until next week. The Rule is simply --Do not modify your bike the night before a ride-- Me being the sucker that I am for new parts, immediatly forget about my rule and pull off the heavy as hell (I didn't realize how heavy it really was) stock pipe and throw on the new shiny Ti Q2. Now keep in mind that thursday I had changed the oil, drained the carb of the crapy winter fuel we have around here and the bike ran just fine on the warm up ride around the neighborhood. So with the new pipe bolted on I pull the choke and thumb the starter. The starter starts to spin the motor sounds like it's going to catch...and then BANG one of the loudest backfires I have ever heard. I scratch my head for a moment and try it agian same thing but this time I keep diligently pressing the button, and the bike keeps diligently refusing to start and ocassionally shouting at me from the shiny new Q. So I go over the carb, adjust fuel screw, inspect plug and just for the hell of it throw in a new on. Futher attempts to start (by kicking no less, because I have worn out the battery) result in the same refusal to start and some what less shouting from the tail end. Since I have broken my own rule and modified my bike the night before a ride I figured I would see if anyone had any ideas that might save me from taking my trusty 400 on the ride wich I am getting ready to sell so I really don't want to bang it up anymore than it is. So any ideas for this undiciplined rule breaker?