I have a 2001 400 ex and it was smoking white really bad. I was driving it and it died. I tried pull starting it and it worked for about 30 seconds. Now the wheels wont even turn when trying to pull start it. Its really making me mad and i was hoping someone could help me.

 

hey man u rode it way too lean
did u make any mods to it without jetting it?
what happened is u were getting to much fuel and air and not enough oil essentually u cooked it. when it shut down u should have left it because by restarting it u ceased it. before, it would have been much easier to rebuild with a stock piston and rings setup but now u need to bore it and go bigger. not bad but expencive. also u may need to get a new head. yours may be able to be resurfaced but by the sounds of it you may need to replace it.