XR4 burning oil on start up

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.

Valve stem seals.

Seems to be quite common from reading on here.

Valve stem seals.

Seems to be quite common from reading on here.

How big a job/pain in the arse is this to fix?

You gotta pull the head to replace the valve stem seals. A competent shadetree mechanic with a manual can do it in 2-3 hours. Some people have replaced these seals without removing the head but their technique always seems like some ghetto rig job they conjured up over a case of Old Milwaukee.

Is it possible that you overfilled with oil? This is a common mistake on dry sump XR engines.

I think I remember someone having the same problem and it ended up being that oil got sloshed around into the head during transport and that was why it was smoking. Next time you try it let it sit a while after unloading it when you get home and see if it still smokes.

-john

Is it possible that you overfilled with oil? This is a common mistake on dry sump XR engines.

I agree. When filled with the proper amount of oil, the dipstick will read on the low side. Many will add another half quart to bring the level up to the middle of the stick, which will cause the symptoms described in the original post.

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