I recently bought a 2003 xr400 and it works great I have put about 20 hrs on it scence I bought it. Today I loaded up for a ride and when I got to the drop off site I started my bike and if smoked alot and its never done this before. But once it was warmed up it seemed to go away go I did my 2 hour ride no problems. When I got home i washed my bike and then started it again, It was hard to start and once i got it running the was no smoke and then bam it was like a wall of smoke then once it was warmed up it stoped. let me know what you think I would like to get this fixed. thanks.