smoking
 

Had to stop real fast the other day, smelled burning oil turned around and saw it coming left pipe. What would cause this? Should I be concered?

Check your airbox. You may have a small pool of oil in there that ended up in the carbs. Oil in the airbox is caused by just one of two things:

1. excessive blowby carries oil into the airbox through the crankcase vent.
2. overfilling the crankcase, and oil gets into the airbox by the same method.