I bought my '01 YZ426f about a month ago and it wouldn't start once I got it home (wouldn't even try and fire). So I tried a new plug and it fired right up first kick. I then took it to the track in 30deg weather (was excited to run it!) and let it warm up while I was getting ready and once riding it backfired/poped real bad on de-acceleration. Once it was really warm it ran great untill my chain broke (not at the master) which I have never seen happen before and ended my frosty ride. Since then I have started it every weekend and it has started fine untill yesterday...now it tries to fire, but wont stay "lit" It is cold here, but it stays in a insulated garage. Is there maybe something else going on here that I need to look at? Could I be fouling plugs that often? I did use Sta-bil in it a couple weeks ago, could that be it?