OK, so I went to do some simple carburator maintenence on my YZ426 tonight and now it won't start. The task was replacing a worn out needle and emulsion tube with new OEM parts. My bike's got some considerable hours on her and it was getting near impossible to lean it enough with a worn out tube and needle. After a simple switching out of parts I re-assembled and went to test ride....no joy. I scatched my head for awhile and decided to put it back as it was knowing those new parts couldn't have killed the bike but had to be sure. Still, no fire but an occasional pop. I really just need a fresh set of eye's to see whatever it is I can't, figuratively speaking of course.