My 400ex is 4 months old, I have changed the oil often, cleaned the filter and it just recently starting blowing blue smoke and burning oil. Anyone had problems similar to this? Any ideas? My guess is the rings burnt up, but i dont know how.

 

IT may just be your oil.
What type of oil are you using?
You should be using a 20 -50 synthetic for best results.
I run Amsoil 20 -50 with no problems.

 

Your rings may not be bad. They just might be aligned wrong. I'd check that first. Good Luck!