My 2006 Honda 400 EX blows all the oil out the exhaust pipe. What could be the cause? And now sounds like has blowback in top end.

 

Do a compression and a leak down test.

Could be rings or just valve guides.

Have you kept up on valve adjustments???

 

No, it has less than 50 hours on it. But it was wrecked - went down off a mountain - but the engine had no damage - ran great for about 2 months afterwards - then all of a sudden, just started blowing all the oil out.

Thanks for responding.