400ex is smoking! im new at this stuff please read!

[VanEpps44]

My 2001 400ex has been smoking out the exhaust. i am sixteen an have no clue on engine problems. some people have told me it was there valve seals! but! i do not know where or how to replace the seals. if anyone could do a photo opperation of replacing valve seals that would be great PLEASE SOMEBODY!

[01boneless]

if it smokes all the time and is blue your getting blow by....rings or piston and possible bore job will need to be done.
If it just blue smokes on start up its the valve seals...
If its black smoke its to rich
blue= burnt oil
black unburnt fuel

[Mtndew99]

The top end isn't hard to to even without much mechanical experience if you have a service manual and sme wrenches you should be able to replace the valve seals and the rings

[OZ-T]

Is the choke on? They will smoke a lot when the choke is on after they heat up..

It's 12 years old, you just can't expect something that old to run like it did when it was new. My quad is a 02 and has it's fair share of issues and it too burns some oil and I have to add some from time to time, just the way these things are.
You might also check the spark plug, if it is fouled it will cause it to smoke. If it does turn out the piston rings are in fact fried, you can still ride it if you want. These old style honda air cooled engines are virtually indestructible I've came to discover; I used to have a 1995 Honda XR250R dirtbike and one day on a trail ride the oil drain plug came loose, fell out, and I lost all the oil while riding and fried the piston rings. I pushed the bike back to camp, rigged up a new oil plug that would get me by, dumped some oil back into the engine, kicked it over a few times and it fired right back up. Smoked like a really rich running 2 stroke, and had zero compression, but ran! I rode that bike 2 more years like that before I stripped it down and parted it out and got something newer. Certain it would still be running today if I still had it.

Don't be too scared about it man, all these things are part of getting into the sport and learning all about riding. I remember when I was in your boots as well, good luck and I wish you the best!