Ok so today I took the yz 400 to my xc race I pre ran the track 2 laps then shut it down till I was getting ready to race. O f you didnt read my post about the popping I have just re shimmed the valves on it. So I was riding to the starting line just idleing in first and the bike wasnt warmed up yet but it was warmed up enough to run off of choke and it stalls. I start it again and it now has a top end loud ticking sound on the left side. Needless to say I didnt race today:foul: . I have no Idea what it could be. I havnt opened it up yet but will tomorrow. Anyone have any ideas?