Problem with my 400ex but no idea what it is!?

Question

ok, ill try to explain as best as possible. i was riding my 400ex on my track and suddenly it started to bog down, so i stowed and put it in neutral and it died! no idea why, i tried to start it and it was like the starter wouldnt catch it just spun, so i pushed it to my neighbors which is about 1500 feet downhill, i got there and figured id try one more to start it and it worked, so i quickly took it back to the house and parked it. i shut it off and started it about 5 times straight, no problems and it was runing strong, but i noticed that there was a little bit of smoke coming from behind the pipe gaurd, i removed it and the header isnt cracked or broken, but the quads running fine now, i would just really like to figure out why it cut out, wouldnt start, and if the smoke from the header is anything to worry about, thanks in advance, if you can email me any info my email is [e-mail]

Answer 1

Im not saying this is the right answer but i had a banshee that did the same thing and it turned out that i had burnt out one of the rings! I had been riding it pretty hard all day long and was on my way back home when it did the same thing your explaining.  Dont know if this helps but its a start!