valve adjustment and shimming for kfx450r

[bigrailer19]

I've had my KFX450 for about 2 years and if a valve adjustment was needed its prolly long past . But It runs great still, and I'm curious as to if they come shimmed from the factory. I really am just asking who has had it done (valve adjustment), and in what intervols (how often). Any replies are appreciated, thank you!